Utterly brilliant and very well-timed video, as we had just decided that we probably didn’t need Cosy any more now that the winter is over but weren’t sure what would be a good choice for the summer. With the help of your spreadsheet we worked out that Intelligent Go is the one for us; without that, we’d likely have simply switched to Flux without understanding how to make an informed decision. Thank you!! ❤
Many thanks Tim, your efforts are much appreciated. Your video is very timely, I was only scratching my head today pondering which tariff to choose once my Solar PV and Giv Energy battery system are installed next month.
Thanks Tim. I pondered this myself, but I haven’t the time to actually think it through right now. What a great community feel to find solutions to this energy conundrum.
Thanks Tim and Kat. The video and spreadsheet were. A great help. Much appreciated. I ran my numbers through your spreadsheet and discovered that with the exception of one month, my tariff Octopus Intelligent Go was the most cost effective. The only other option was Octopus Flux which was marginally better on one month and I don’t have a GivEnergy battery so that rules Octopus Intelligent Flus (which was a bit better on one month). I appreciate the spreadsheet is not necessarily precise, but the clarity of the numbers matched my best guess and I’m happy not to need to jump tariffs twice a year with the reasonable certainty that it’s wise and not just lazy.
Many thanks for this. It’s very helpful. However, forced discharge does have an impact on efficiency as alongside usual inverter losses it takes more than a nominal amount to push out high discharge rates to the grid. There’s also an impact on battery longevity.
That's why it's a rule of thumb, not a thorough detailed calculation including all that stuff. The idea was to make it as accessible as possible to make it easy to apply. All those other details are secondary effects for those who want to fully optimise their decision; they won't significantly change the answer.
Great analysis and thanks for the video. I had just watched Gary's video, and when I looked at your chart I didn't immediately realise that it relates to the ratio of generation/consumption during the period of the tariff switch, i.e. in summer months the generation to consumption ratio will be a lot higher than the winter. I've not got my system installed yet (that's next week - exciting times!) but I'm researching to see what tariff to move to, and IOG was the 'obvious' one, until I saw this video. I've got info for our current grid use, so I'll have to take a punt on what I'll get from our 6.8kwp installation over the summer. I've also got shares in Kirk Hill wind farm with Ripple, so that's yet another curve ball! Great work, and thanks again
No problem. By the way, you should have estimated monthly generation figures from your installer, but if not you can use the PVGIS tool Gary mentioned to get a decent estimate instead. Then you can use those figures to compare against your monthly consumption. I hope that helps. And best of luck with your installation!
Swapped to Flux on the 15th. Made a simple spreadsheet to try to work out which was best for me. Didn't look at intelligent flux as I prefer to keep control of my equipment
Yup, that's totally fair. I'm very interested to see how Intelligent Flux works in practice. If I don't get on with it at least I can switch to regular Flux pretty easily.
@@TimAndKatsGreenWalkI tried to find out more details of the model octopus used but couldn't find anything. Is it a modelled on each customer usage and solar like predbat or just their supply / demand. Will be interest to see what you find out 👍
Been on Go since 2nd October. Not used any grid Import for a week. And hated watching export at 8p/kwh so this evening I moved back to Flux. (Not intelligent flux) Octopus have backdated it to midnight so 24kwh exported today at.18.5p (£4.44) rather than at 8p (£1.92) Too late to do a force discharge between 4-7pm. There's always tomorrow 😊
Thanks Tim, Very informative video and very useful spread sheet. With my parameters in the spreadsheet it confirmed I should change from Go to Flux which I've just done. A suggestion of a small mod to the spreadsheet. Change the fill colour of the Tariff prices box columns to the same coulour as the trariff headings in the table below. Regards David.
Good stuff. I'm in two minds about your suggestion for the colours, as I want all input cells to be the same colour to make it clear that those are the ones that can be safely changed by the user (i.e. the light purple). I felt that the vertical alignment of those tariff prices with the tariffs below should be sufficient to make it clear what prices refer to what tariffs but I can see how that might not be quite clear enough. I've compromised by adding an additional row of tariff names above the price input block, so hopefully that satisfies both requirements for clarity.
Interesting to see how close Go and Flux are. Thank you. Plugging in the numbers for my 4 kWp system Intelligent Flux would save me £20 a year. Using Go for four months would save around £35 a year. Not that I can get either tariff at the moment! I look forward to seeing the reports on how Octopus use your battery. I set my system up to force export 18:00-19:00 every evening during the summer. If that does not happen then Flux is likely going to work out better than Intelligent flux for me (assuming they even expand to support other battery systems).
Another great video Tim. I did this analysis about a month ago to compare IOG with Flux, using a modified version of your COGS spreadsheet. For me, it suggested Flux would be better for June and July only and this is confirmed with the 1.4 rule. However, I suspect the Flux rates will drop further in July with the next price cap change, so even that may be optimistic. I'm sticking with IOG throughout.👍
Just one point on solar generation, any solar generated will always be used in the house first and any excess used to charge the house battery or be exported, you cannot actually export all your generation even though you have a battery, you need to set the battery to force export to compensate. Our Powerwall does this automatically, it simply works out we have spare battery so exports this, it ensures the house still runs off the battery until 11:30pm. Your calculations are very useful and I think confirm my decision to simply remain on Intelligent Go all summer, the three cheap hours overnight are not long enough or cheap enough to charge our EVs and our 15p export rate is fixed till next January, there is always a possibility this will change in July if prices continue to go down, so sticking guarantees this rate next winter.
Yes, I did mention that you'd have to force export some battery to compensate for solar being used by your house (in the part where I talk about my assumptions), although I didn't explain it particularly well. As long as your export rate is higher than the off-peak import rate (modulo conversion losses) this is a good strategy regardless, as you are doing with your Powerwall, so you'll probably be doing a bit better than my simple calculations suggest. I think sticking with IOG all year is a decent option for a lot of folks, actually, as Flux and IOF are only really better than IOG when you have a bigger than average PV array.
Thanks for your data & video, you have more clearly defined my own looser calculations with my own battery setup. I have some differing characteristics, but the base data is similar enough to draw the same conclusions. Thanks for doing the hard work 👍 intelligent Octopus Go would give you extra (6hrs) overnight cheap rate window as a minimum of course, just need to update smart meter.
This is exactly what I needed to know in order to decide when to switch tariffs! We are on Flux but have an EV now (Also Givenergy charger so intelligent Go not an option), so needed to think about when Intelligent Flux is better than normal Flux. 1.25x solar seems to be the inflection point.
Excellent, I'm glad this is useful for you! I'm hoping Octopus will get the GivEnergy EV charger integrated into Intelligent Go sooner rather than later. I might chase them up and see if they have a timescale planned.
Thanks again for another great vid! I don't have an EV, my system is GivE and PV's, recently installed end of Jan 24. I moved to Go Lite as soon as I could with export rate of only around 8p. Decided to bite the bullet and change my tariff to IOF, be aware that I was in to my 3rd week until the switch was completed. Had to call Octopus to chase the switch, very odd since I was already exporting with Octopus via Go Lite. Anyway, the switch was made on 19th March. My peak export rate is 35.5p (4pm-7pm) and std rate is 26.6p (7pm-4pm). Something a bit odd is happening when I look at my tariff export card in the GivE portal. If I take export figs on 20th March, I exported a total of 8.9kWh but only 2.7kWh was exported during the peak rate, 3.85kWh was exported between 2.30pm and 4pm, 1.3kWh between 7.30pm and 8pm and the rest exported during the day outside the peak rate! Similar details have happened on the 19th to 22nd Mar too. My assumption when I switched was that almost all of my export would be within the peak rate. I have reached out to Octopus a few days ago to explain, still awaiting a response.
Yeah, that is odd, I'd also assume all the force exporting would happen between 4 and 7pm. Of course you will be exporting some excess solar outside of the peak time so maybe that's it? Look at how much of the export is from the battery vs how much is from solar. You might find the battery is only exporting at the times you expect.
Good video. Switched to Flux from Go on 18th March 2024. Octopus immediately switched the import to Flux but the export can take up to 14 days so stuck on 8p export and cannot discharge between 4pm-7pm for the 28.79p per kWh. One thought for your calculations: We have a 6Kw inverter and a 7.36pwh solar array the generation has been hitting 8.5 kWhs peak over the last week but once the battery is full is clipped to 6kWH. If your inverter is small you are losing out on some generation which is free and can export earlier in the day when the battery is full.
The idea was to keep the calculation as simple as possible. Adding in clipping would introduce significant complications so I ignored everything along those lines to streamline it, sorry about that. I doubt it would significantly change the broad conclusion though, if it's any consolation.
I *don't* (yet) have enough battery to power the house all day. Just putting in last year's actual figures for consumption and export, ie breaking one of the assumptions, reduced the Flux (we're not eligible for Intelligent Flux) suggestion to just two months, May and June. So I modified the sheet to include percentage of import according to rate (the two IOG rates). Not ideal of course, given several of the variables, as well as not being able to find rates for Go, Cosy or Intelligent Flux, but I don't s'pose those would suit anyway. It did bring the monthly cost column for the tariff I'm on (IOG) much closer to what we actually paid, so it seemed it might be at least slightly useful. Just that modification didn't make any change to the cheapest-for-me tariffs, still suggesting Flux for just May and June.
Yeah, if it's reasonably close that's good enough, really, as there are so many other things that can shift it one way or another. If the choice between two tariffs is marginal then the choice isn't super important. It may not even be worth bothering to switch for just two months of the year, and stick with IOG all year.
Only had my system installed in December (6.5kwp array and a pw2) Factoring in the saving sessions march will hopefully be the 1st month we have a negative bill, and thats on IOG with a model x which isnt exactly the most economical of EV's So looking forward to seeing how it performs over summer.
From what I've heard, Octopus don't make particular effort to export much during peak rate with Intelligent Flux - they may export quite a lot of solar directly, rather then storing it in the battery. So maybe only a small fraction (0.1, 0.2 ?) is exported during peak. Perhaps separat that out as a different input parameter ? For the other tariffs, surely how much you can export during peak rate is dictated by battery size - in midsummer, you can't expect to export 20kWh in 3 hours from a 9kWh battery, for example. Any consumption during that time isn't exported, and you need to hold some back for evening, to avoid importing at day rate. But in the cooler months, you might be able to fit most of the generation into your battery for export during peak rate. So perhaps model it as,say, up to 6kW per day exported during peak rate, and the rest of the export at day rate. (On the longest days, there will still be some PV generation during peak rate, to complicate the modelling further.)
The point of this video was to keep it as simple as possible, that's why I don't have loads of input parameters and make some broad assumptions. I feel there is more value to getting a "reasonably good estimate" for a lot of people rather than getting the perfect value for the small number of folks willing to model all the tiny details. By all means take a copy of the spreadsheet and make you own additions, however. Regarding Intelligent Flux, watch Gary's video where he explains in more detail how Octopus manage the battery charging and export.
I’ve been enjoying playing the Agile import/export game for the past few months - not sure I’m willing to give away full control as HomeAssistant & PredBat running well. Likely Flux could be better for me. Interesting rules of thumb 👍
@@SimonApperley I found this recently, it's pretty handy: octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/ The short answer is, yes, it seems they do!
@@TimAndKatsGreenWalk I wasn't brave enough to switch to Agile until the negative plunge pricing this week, changed about 2 days before it and I've already saved about £20 in a week, it's silly how cheap it is, it's compatible with all chargers as well, if you can set a price cap on your charger and it pulls octopus rates, it'll charge at whatever the cap is and below, I set my Ohme to charge at 0p and I got paid to charge my car, admitedly it was only 30p, but I got 40 odd kWh and 30p profit, this week I've averaged 21kw daily at an average cost of £2.35 a day, which works out at about 10.25p/kWh, no solar or batttery storage, just EV and Agile.
@TimAndKatesGreenWalk Thanks for your efforts with this video. I have a Tesla so currently on IOG, but I only very rarely charge at home (free charging at work) so I'm a pretty unusual case.. I wonder how I can maximise income from solar export over the summer. It's a little tricky to work out my usage as I generally charge the batteries fully in the cheap rate and then discharge them for export at the end of the day before charging again. If I look at the Octopus app and my Growatt Inverter app, I can see that in 2023 I Imported 10000kWh, and I exported 6000kwh, my solar generation was 6000kwh. I'm not sure where that leaves me... 🤔 🤷♂️
It sounds like sticking with IOG all year is not a bad choice for you given those figures. You might find a couple of months over the Summer you'd be better off with Flux, but probably not by much. If you have your estimated monthly generation and consumption you could plug your numbers in to see. In either case, charging cheap and exporting higher, as you're doing, is going to be beneficial.
Thanks for getting back to me. It seems to me that many of these kinds of videos and spreadsheets don't look into the possibility of dumping stored energy to the grid at peak rate, and maximising profit from battery and solar installations. Just converting total usage and total generation to various tariffs doesn't take into account the possible behaviour changes that could be made to maximise profit. I'd like to explore this myself but haven't got the Excel skills.
@@themorfill yes, force exporting will certainly change the equation a bit but for this particular video I had to make some broad assumptions to keep the calculation as simple as possible. Although, by force exporting you'll always get a slightly better result than my spreadsheet suggests so it can be viewed as a conservative estimate.
I think you need to look at Octopus Cosy - it's available to anyone one with heat pumps and offers two off peak periods at times when it's more useful: 4-7am and 1-4pm. For us, this usually means we are exporting at Peak times and never importing then. Things are nowhere near as simple is your assumptions make it though, for instance if our solar panels pointed more westerly we could be selling directly to the grid at peak value. Whereas our SE facing panels will have the battery charged to 100% by 10am and then we have to sell at a low rate. Battery capacity and Max Charge/Discharge rate, also makes quite a difference in the calculation.
Take a look at the spreadsheet, I added Cosy to it after this video. If you've got solar and battery, and an EV (so you can get Go or IOG), then Cosy is beaten by Go/IOG in most situations over Winter due to the significantly lower off-peak import rate you can get. And is beaten by Flux/IOF in Summer due to the better export rates those tariffs can get. If you only have a heat pump and don't have a battery or EV then Cosy is a viable option, but as soon as you add those other things it becomes less attractive.
Interesting and I like your idea of trying to produce rules of thumb that would suffice instead of doing detailed analysis. I was looking at my own consumption and generation data in Home Assistant and I’m not yet at parity on the two, so confirms my thinking its not yet time to switch but its getting there. I’ll have to do some massaging of my data to work out my historic consumption which I don’t easily have. Have solar generation but last year I changed supplier and only got export setup in August and Home Assistant in November. Unfortunately the givenergy portal data is very inaccurate for multi-inverter setups. It would have been really useful if you’d covered non-EV tariffs as well like Cosy, Tracker and Agile. I’ve done a rough comparison of Agile vs Flux and think based on last September data that Flux is only about £5 a month better off. More analysis needed …
These are the tariffs of interest to me, and probably most folks with solar setups, so I decided to keep it focused rather than making the video too long and complicated by including other tariffs. There are too many now!
Hi Tim, thanks for another informative video - I have been pondering this over the winter and for me Intelligent go seems best. I did wonder about your assumption though regarding for ed exporting a days worth of usage from the battery - my battery can power my home whilst all solar is exported, so no assumption required - is this not possible with the givenergy system?
I would love to be on IO Flux for the summer. However I have dual AC3's and apparently you can only have 1 giv inverter to join IO Flux. 1 device, 1 inverter and multiple batteries are fine. Same issue having dual zappi's and switching to IO GO.
New changes to Cosy tariff coming. New video? 😉 My own spreadsheet takes my use and calculates my total use in each of the 48 half hour time periods and applies the tariff rates to estimate a cost (or uses the average half hourly tariff rates for Agile).
Hi T & K I see ASHP get a lot of publicity and you never hear about modern night storage heaters. Perhaps a comparison might be an idea. I have 4 Dimplex Quantum RF100 heaters and a Nissan Leaf which does not get much use. I use a max of about 250 kWh / week in the depths of winter then of course it tails off. I am on Octopus GO at 9p off peak. I have 3.5kw of solar plus iboost and An 8.3kwh GivEnergy battery. Plus FIT. I use well over 90% off peak power and no gas. I also have a Mixergy hot tank.
A few people have asked me about storage heaters and how they compare to heat pumps. I should do a comparison video, you're right. My answer is that heat pumps are over 3 times as efficient as storage heaters, so use a third, or less, of the total electrical energy to get the same amount of heat out. That's why they're so good. Storage heaters can cost a similar amount to run as heat pumps, assuming you can charge them up with off-peak electricity. But if you combine battery storage with a heat pump you can also at least partially run your heat pump using off-peak electricity too (in fact we have used only off-peak electricity for our heat pump system since mid January, although we have 14.7 kWh of battery storage), so then a heat pump becomes significantly cheaper to run than storage heaters. Of course, if you can't install a heat pump, for whatever reason, storage heaters are probably the next best thing.
@@richardspencer6695 I show my monthly data in the video (and in many past stats videos), if you're interested in comparing, although I caution you to not draw any conclusions from that. Doing those sort of comparisons is pretty meaningless as lifestyles and houses are all so different.
@@TimAndKatsGreenWalk yep it is difficult on these vids as of course last weekend we had a good one and basically used 90kwh for free but you cant model. Not everyone is like me with ADHD and checking the data/prices every few hours ha ha If you want a set up and go tariff I think IOG is the best with all the caveats on EV usage and shiftting usage to night.
@@ianrob4760 I'm considering doing a follow-up video for folks who don't want to keep switching every six months. I would agree that in that case IOG is almost always the best choice for most folks.
@@TimAndKatsGreenWalk yep, I should state I work in IT doing data monitoring so just waiting for this to go even further - czcams.com/video/g-RQ0dOPTtc/video.html and of course for some people this is just too much to handle, thats normal.
For Flux have you considered what happens on days when you have low or no generation if you're on GO you don't have to worry or does the Intelligent Flux do that for you. When Sunday roast is on a low generation day I sometimes use most of my 15 kWh batterry
The sunny days more than make up for that. As I said in the video, this is a rule of thumb, if you want a fully detailed calculation you'll have to do that yourself.
Thanks Tim, very instructional. Point 3 in your assumptions says all your solar generation is exported. Does the fact that I cannot run the house off the battery and simultaneously export my solar at the same time mess things up a bit. i.e my battery will always charge from solar until full, only then will it start to export excess while at the same time feeding the house, I can not separate the two. or is that what you mean ?
Yes that was the assumption I was least happy with as well. I guess the counter argument is that when you are using solar to power your home you don’t need to drain the battery and so you don’t need to import as much overnight at the cheaper rate. But it does skew the figures
That assumption works out to be valid if you force export some of your battery too, equivalent to what your house used from solar (excluding any solar that went into your battery). And that only matters for Intelligent Go, the other tariffs aren't really affected by that assumption because of the relative import and export rates.
Very helpful - I’m on Flux but I’ve only had my system since Oct last year so I don’t have a full year of consumption and generation. As generation starts to rocket up, like you I’m in 2 minds when to take the intelligent plunge! Programming the battery is a pain in the @ss. I was surprised that in a cloudy/sunny/rainy day, we generated 24kw from 12 south facing panels - a record for me since installation. As you say it may be easy to switch back with limited fuss. So your advice is go for it from April 1?
Well, I'll be switching early April, and it sounds like it'll be about right for you too, but you can always check using your estimated monthly generation. You should have that from your installer or else the online PVGIS tool is very good for that too.
Thanks, that's very helpful. I started the process but I'm getting a couldn't connet device error message. "Make sure that 1) your device is fully set up on the GivEnergy app 2) Your battery is connected to the internet 3) username and password is correct" Are 1 & 2 the same? My Give app is fully functional but is there something else I should be doing? Have you tried to set this up too? @@TimAndKatsGreenWalk
You need IO Go I can't Flux getting anywhere near it once you've taken into account charge/discharge losses and wear and tear on the battery. Also the small cheap rate window means the house battery would never get a full charge overnight and likewise for the car as when I use it I tend to come home with it empty and want a full charge.
I agree, the 6 hour off peak import window with IO go gives much greater opportunity to fully charge home batteries and EVs, it also means the home battery only has to cover 18 hours. Additionally, the 18 hour period where exports generate 15p (7.5p ‘profit’) means variable solar generation matters less and the absence of the need to force discharge at certain times are big bonuses which are hard to quantify on a spreadsheet. I think system adaptability and tariff flexibility are key enablers to be able to adapt to future tariffs which will surely be offered in the coming years.
@@TimAndKatsGreenWalk , it depends how you define high generation. Over the last 4 years I’ve generated 8000kWh per year on average. My consumption is 15-16MWh annually, so against your 1.4 criteria IOgo is indeed the best option. My point is that with higher consumption / generation, your perfectly valid assumption about 100% battery use and 100% solar export can be constrained by the shorter windows of off peak import rate and peak export rate. Therefore the shorter import window with Flux can constrain the ability to fully charge a battery that can support the whole house throughout the day.
I was surprised by Intelligent Flux in that it actually hardly uses the battery; it discharges it at full speed in the peak period but other than that it doesn't discharge at all, and it either charges from solar or very slowly during the afternoon if it's not sunny enough. It must be one of the best ways to look after your battery. We were on it briefly last autumn but will probably be back on it when it gets a little bit warmer.
Interesting to hear your comments at 9:30 about force exporting as I havent worked out yet how to run the house only from the battery (if thats possible) without solar first topping the battery up before export starts (Ive got givenergy also) and so I was toying with the idea of a forced export from say 2130 to 2330 to near exhaust the battery (or maybe exhaust it) before forced import starts at 2330 to fill up the battery again. I take it this is the scenario you were outlining? Obviously you do lose a little bit through the inneficiency of going via the battery before you export. I'll have to start monitoring what the battery % is in the late evening and also what the export rate the battery can do is (I think its 3.6 even though Ive gota 5kW inverter, but not sure but even with everything ramped up asa test in teh hosue I think the battery maxxed out at 3.6) Looking at your graphs, staying with Intelligent Go also seems simple and avoids the hassle of changing tariffs a few times a year albeit at the cost of giving up some money. My install is new (as is IO I only switched yesterday ! ) but i reckon I'll be on the borderline of IO and Flux, so again sticking with IO seems an easy route. Plus, although my usage is ~6000 kWh compared to estimated production of ~9000 kWh, half that consumption is the car which is at very predictable off peak times so that maybe skews the calc back to IO? Anyway thanks for this outline.
Sticking with IOG is a pretty sensible option for a lot of folks, I think. Although switching tariffs is really pretty trivial with Octopus, it can be done almost instantly in many cases.
Yes, that is an issue. We're the only ones with solar in our local area so no problems for us right now but it'll be interesting to see how that changes as more folks get solar.
is it possible to set the givenergy up to not pull from solar? your assumptions about ‘all house load can be covered by battery’ fits me, but as I use some in the morning, the battery will always first top up and only export the excess. So the battery is never really ‘exercised’. Does that matter in the end or does it all sort itself out in the end?
If you force export a bit from your battery, equivalent to how much solar your house used during the day, then it all works out as if you powered your house only from the battery. You can set your GivEnergy battery to charge from solar only, but not grid only, it seems.
Hi T & K Two questions, can I go on octopus flux if I am already on a feed in tariff? And how do modern night storage heaters compare with an ASHP for cost and power usage? I am on octopus go and my car does not get much use being retired.
I believe that you would have to give up the deemed export part of your FIT in order to get the Flux export. And have a smart meter. You should be able to keep the generation part of your FIT though, you'd only have to give up the deemed export part. As for storage heaters, they will certainly use more total kWh of energy to run than a heat pump (probably three times as much), but if you heat them overnight at low rates then it will probably work out similar cost. However, if you have home storage batteries and solar then you can use those to help support a heat pump while it runs during the day (as long as your battery is of a decent size), in which case the heat pump becomes a lot cheaper to run, as you can effectively use off-peak electricity while also using a third of the energy compared to storage heaters.
Sorry to ask a basic question but I'm quite early on my journey. What is the best way to work out the consumption? I had panels and a battery installed late summer. Before that I worked away from home alot and then retired so my bills are a bit all over the place. On the app I have PV, Load, Export, Import, Discharge & Charge. I wanted to get through my first winter to see what performance was like, pleasantly surprised since mid January. One battery is enough for more than a day but I will get a second.
It sounds like Load is what you want. It should be roughly the same as your grid import plus PV to the home (if your app breaks down the PV in that way).
@@TimAndKatsGreenWalk Thanks Tim, had a nose round and found I can customise monitoring parameters. I wouldn't had thought about it if I hadn't seen this video 🙂
Hi Tim, 1.4? Isn't it funny how Pi turns up everywhere? 😂 Your predictive graphs look similar to my estimates predicting April and October being the tariff swap over points. I was on Flux over summer and have survived on Intelligent Go over winter funded only from the summer surplus export banked into the account which is only coming close to zero now when I'm getting to the April break even point again - so it looks like it's proved possible to have zero bills over the whole year. Over summer I was not AC charging the battery on Flux so it was entirely supported by PV in maximum self consumption mode. Had I AC charged I guess that would have gone out as expert when the battery got to 100% which is more likely earlier in the day before the peak 4pm to 7pm time. I didn't Force Discharge and only let that happen naturally on sunny evenings. So, I suppose there's some further advantage to be had possibly. Oh, and although summer running comes from PV and battery, on the coldest winter days I was running flat towards the end of the day with the heat pump load so I had some peak import. It's all good stuff overall anyway! Interesting to see your estimates.
@@TimAndKatsGreenWalk I was thinking how it fits with your assumptions - so main differences being (1) no AC charge when on Flux (but that might not be best policy), (2) my battery runs flat in winter and (3) I think most export will be earlier in the day especially if AC charged as the battery gets to 100% earlier, so there will be well less than half the export in the peak time 4pm to 7pm - unless you Force Discharge. So, is your presumption that when on Flux you always AC charge and Force Discharge so export is 50:50 split across the two export rates? I appreciate you are trying to keep it simple so not sure if that helps or hinders.
@@johnh9449 for Flux it actually doesn't matter whether you charge up overnight or let the solar do it, since the overnight import rate is so similar to the day export rate. The assumption of 50% peak 50% day export would be affected, yes, but you can adjust that in the spreadsheet based on what you typically see in your data.
Hi Tim. Octopus won’t do intelligent flux for Powerwall 2. I have gone back to Agile from Flux as I can’t see the point of the daily import and export prices being almost identical. Am I missing something? Chris Mc. Only batteries, no ev
Intelligent Flux is only available for GivEnergy systems. Go check out Gary's video comparing Flux with IOF, that's a good summary. The main benefit is the huge export rate, so if you generate a lot you'll get more paid back to you than if you're on regular Flux (as shown by my chart).
Tim. Early in the video you talk as if you can make the battery run the house and the solar go direct to the grid. Mine only goes to the grid once the battery is full. Is there a GivEnergy setting to force this?
I was wondering this myself. In practice you can achieve an equivalent effect by force exporting some of your battery during the day, but that assumption was more about making the calculation simple than the practicalities of it. Having said that I shall be experimenting with the settings to see if it's actually doable.
@@TimAndKatsGreenWalk thanks. We enjoy your channel. Unlike a lot of your followers I’ll be glad of the day when Octopus just controls it all for me (solar, charging, import & export), and I can forget about it. 😀
@@richardeskins haha! Yes, I think the idea of IOF is actually a really good one for folks who don't want to do all the fiddling. It's a perfect plug and play tariff imo. I'm keen to see how it works out for me over the Summer.
Strange you haven't got new rates yet. I got mine about a week ago from octopus for regular flux. Think the assumptions stated in video are more or less on the money in that day export and import are close, within 0.3p per kwh.
I only got notification of the new Go rates, since that's the tariff I'm currently on. They didn't tell me the new rates for all the other tariffs. Good to know my assumptions aren't too far off though.
Tricky. Monday - Thursday 8-5 and Friday 8-2 use 8000kwh per year and produce 6000. Battery present no ev. However, we don’t work at the weekends. I was thinking of just using intelligent flux but maybe just octopus go all year might be the better option. I mean in summer basically 4 days per week oct go is probably better and 3 days per week summer intelligent flux. Winter oct go all the way. Just installed so no figures yet
You should have an estimate of your monthly generation from your installer so that'll help. Otherwise there's a good online tool called PVGIS where you can get a good estimate instead. In either case best of luck with your decision!
@@TimAndKatsGreenWalkthanks Tim. Annoyingly my provider hasn’t given me the monthlies. I can estimate it from our other work site which has a 19.5kwh array (no battery) from 2016 which was a great idea as just got the FIT also. Anyway I think that (based upon the graphs and educationally guessing) the intelligent flux (for ease) is probably best for the summer april - mid October and then October go. I’ll keep an eye on it and see what they do with the battery! Really wish intelligent oct was a battery non eg option. The summer is probably just over 1:1 and with lots of export days that probably swings it and the tariffs are all fairly close around that ratio… v interesting anyway and thanks a lot 👍👍
@@simoncove1 yeah it's complicated! At the end of the day having a solar system will always be beneficial, so as long as you find a tariff you're happy with it's all good.
If I force export, does octopus pay 15p no matter what time? thinking from an automation pov could you schedule your battery to force discharge to eg 10% at 10pm or so, so you’re safely not going to pull any peak grid, then recharge overnight?
Hi Tim, not sure which EV car you have but does Octopus Intelligent Go not allow direct connection regardless of which EV charger you have, we have just bought an BMW i3S, had Easee wall charger installed and have 5.4 Kw array, GivEnergy Hybrid 5Kw inverter with 9.5Kw Battery. I was able to join IOG and use the 7.5p overnight tariff, I’m currently waiting for my export tariff to change to 15p Kw. Your graph seems to make IOG the best all year round tariff for your circumstances. I find your channel very informative, keep up the good work.
Unfortunately IOG is only compatible with certain EVs, or EV chargers. In other words you can either have a compatible EV, or a compatible EV charger (or both). If neither your EV nor EV charger are compatible then you can't use IOG. Sadly we currently have neither. IOG would certainly be best for us over the Winter if we were able to to get it, but over the Summer Intelligent Flux would end up paying us slightly more (i.e. more negative on the chart). If we didn't want to switch every six months then IOG would be the best single tariff for the whole year. I'm hoping we'll be able to get IOG once Octopus include the GivEnergy EV charger in their list of compatible chargers (before October, I'm hoping!).
@@TimAndKatsGreenWalk I’m sure the GivEnergy charger will be adopted shortly as they are certainly one of the main players in the renewables field, I thought about the GivEnergy charger myself but opted for the Easee as I wasn’t too concerned about the smart feature as I’m not looking to use solar to charge the car, certainly not when you can get 15p Kw EXPORT and charge during the off peak, it suits our current circumstances as the i3S only has a 42Kw battery which can easily be charged during the 6 hour window however when I change my car next year our opinion might change if we go for a 2nd EV with a larger battery, we might require the smart facility of IOG at that point. As it stands we are having conflict issues between the 3 apps (BMW, IOG & Easee) so have disabled the smart feature in OIG and only use the BMW app to schedule charging in the off peak period.
Yes, I'm sure the GivEnergy charger will be supported soon. One thing to bear in mind is that to be on IOG they need to see you do a charge using that system every now and then or else they might kick you off the tariff. So you might find turning off the other two apps and letting IOG do the charging is the better option. Presumably Octopus is taking control of either your car or charger in any case, so you can set the other app to just charge all the time when connected (and the IOG will only provide the juice when it chooses to).
@@TimAndKatsGreenWalk cheers for that, I’ll keep an eye on my tariff and see if octopus kicks me off it, I tried all sorts of permetations with the OIG app and couldn’t get it to work as intended, looking at various EV forums and it seems others are having a similar issue regarding the intelligent charging. I’ll investigate further as I’m sure this issue will be down to user error and see if I can have it communicate with only the OIG app.
Hi Dave, not quite related to this, but the figures of Givenergy app and portal are higher than octopus state in ‘my usage’ figures for export and lower for import. Only a few kilowatts over the 3 weeks my system has been on and 10 days exporting but wonder if you or others had similar and how to resolve.
Yes the fix is very easy, you simply have to learn to ignore the givenergy figures. 😂 Joking aside, the givenergy figures are 5 minute samples that are then extrapolated to be what happened for the full period of time. So if you have the kettle on at the 5 minute mark, it’ll look like you had the kettle on for the whole 5 minutes. Likewise if there was a cloud going overhead and your solar was low, the 5 minute data will be at that low level. Its awful but its just the way the givenergy portal works. If you want more accurate figures you need to do something like install home assistant and get the data off your inverter directly
My GivEnergy figures are pretty close to what Octopus say, although certainly I'd take the Octopus figures as the truth since that's what your bills are based on. It's Tim by the way, like in the channel name 😉
Tim, with the 1.4 times rule, if my home uses 5,500kwh and my solar will generate 3,000kwh, then am I right in saying that my case doesn’t satisfy your rule? Thanks
If you break it down into months you may find some months where you generate more than 1.4 times your consumption, and some less. Worth seeing if you can find that data.
@@TimAndKatsGreenWalk Thanks for the info. We just had solar installed in December, so I'll collect data in this first 12 months. On a positive note we're on Octopus Intelligent Go, which by your model looks like 2nd best, so happy to go with that for the first 12 months. Great video - thanks Tim!
@@bloodynorahvan2203 you should also have monthly estimated generation figures from your installer. If not, you can use the online PVGIS tool to get those estimates instead. That should give you a bit of a headstart and save you waiting a year.
Does seem strange that octopus 🐙 has giv energy battery as the only one that works with intelligent flux but dont have their charger compatible with intelligent octopus go.
@@TimAndKatsGreenWalk But that's not correct according to the image (and my current setup). Outgoing Fixed at 15p is compatible with Intelligent Go. I force-charge my battery at 7.5p overnight and then export all my solar during the day at 15p - have been doing so for almost a year now.
@@Rob-ct4xp yeah, that's what I said. You can get outgoing fixed with IOG but not the other tariffs, i.e. you can't use it with regular Go or the two Flux tariffs.
You'd have to find a way to prevent it from diverting during the peak period, while your battery is force discharging, but if you can do that then you could use one. Although in practice that's easier said than done, and you don't really gain anything since exporting to the grid is the same price as importing, so there is no benefit to solar diverting at all on Intelligent Flux.
I actually change the settings on my eddi to prevent soar divert during the Summer for this reason, as I don't want the eddi seeing my force export as solar excess, since I want that to go out to the grid, not into my hot water. The reverse of this, basically: czcams.com/video/tNPE2G4JPZI/video.htmlsi=GXu5MqCq0yMtS_fg
Hello Tim. You have a lot of interesting videos. You might be interested in what I have done. Firstly I've been a house builder for 40 years now retired. I have been a geek about energy. Our last house was 500 sq/m. We had a 12Kw wind turbine plus solar and we were making £7K a year. We were early with the FIT luckily. Our current house - 8 year old is built to passive house standard. It's 400sq/m and the heating requirements for heating is 4Kw. We have a 7kw air source heat pump with underfloor heating. Yes even a passive house needs some heating when it falls to zero. We are all electric but have only recently installed 8Kw ( 20 ground panels) and 2 x 9.5 Givenergy batteries. You missed out COSY tariff from octopus. off peak 04- 00 to 0-700 and 13-00 to 16-00. Not sure it's the best tariff. Our usage is about 20 to 24 Kw/hrs per day no heating on. And about 44kw/hrs for a few months over winter with heating on.One major problem is that the company that installed it quoted for an 8Kw inverter. But they only fitted a 5Kw inverter. Output and input is only 3.6kw. Turns out the 8Kw is 3 phase. I will have to sort this one out. I'm trying to find out if they can fit a second inverter. Our annual energy use is about 12000Kw/hrs I'm still trying to get to grips with settings in the portal. Or just to set it to Eco and leave it. It's early days though.
I'd love to build a passive house one day. I'm not sure it'll ever happen but if Kat and I ever get the opportunity we'd definitely love to try. Yours sounds amazing, I have to say. I deliberately left out Cosy as I don't believe it would ever be the best option for the Summer (since this video was aimed at the choosing the best tariff for the Summer). These four are the ones most folks with solar are likely to be considering, I believe.
@@TimAndKatsGreenWalk You could be right about Cosy tariff. Just been listening to Gary does solar and Intelligent flux sounds good. I think that might be better. Still have to get my export sorted out first. Thanks.
@@davidgray2825 after your comment about Cosy I went and added it to my spreadsheet out of interest. It looks like it's never the best tariff (under my assumptions) with Flux/IOF/IOG beating it in the summer and Go/IOG beating it in the winter. I think the main benefit of Cosy would be when your battery isn't big enough to support your house load plus heating, so you can double charge it to help mitigate that. Anyway, it's in the spreadsheet now!
As far as I understand it you can switch between any of their smart tariffs every 30 days, with the exception of the Tracker tariff. Take a look at their tariff terms of use, it may have changed since but that's what it said when I last looked at it a few months ago.
If you want to be sure I'd suggest emailing them and asking directly. When I did that six months ago they said I could switch back and forth every six months with no problem.
If you don't have a smart meter your options are very limited, I'm afraid. It'd be standard tariffs from any supplier, so no time-of-use tariffs like Octopus Go, for example. If you can find any way to get a smart meter installed it really would open up a lot more options for you.
@@TimAndKatsGreenWalkThanks Tim & Kat, yep that's what I thought. I've had at least 3 meter changes over the last 2 years and they still can't get a connection. When you think how many connected devices we have all around these days it's pretty poor that many meters are still unable to connect. I'm planning on getting another electric car so I can make better use of my spare solar in the summer.
@@Bendydog ah, that's a real shame. I wonder what the problem could be. I guess you're quite out in the sticks? I believe smart meters rely on the mobile data network so if you're in a dead zone I guess that would do it.
I actually live in a busy town in Northumberland so when I moved in I didn't expect there to be an issue. I even contacted Greg Jackson directly and to be fair they have been very accommodating.
@@Bendydog interesting. I had no idea it could be difficult to get a smart meter to connect. It does sound like something that they should be working on to improve. Hopefully a solution can be found in your case. It must be very frustrating.
@@TimAndKatsGreenWalk You are right, it’s down to each one’s circumstances. Eon off peak time is 7 hours vs octopus six hours. I am with octopus and I have no plans to move to eon, but the seven hour off peak would suit me better to charge our two evs
The Generation column on your spreadsheet is white, implying we should not edit it. Is that right? I would expect we'd want to plug in our own expected generation figures.
Wonder how many people are playing this electron game... Surely they all watch this informative channel... Keep up the good work.
Thank you. I hope it helps a few folks, at least.
Utterly brilliant and very well-timed video, as we had just decided that we probably didn’t need Cosy any more now that the winter is over but weren’t sure what would be a good choice for the summer. With the help of your spreadsheet we worked out that Intelligent Go is the one for us; without that, we’d likely have simply switched to Flux without understanding how to make an informed decision. Thank you!! ❤
That's great to hear, I'm glad it was useful.
Many thanks Tim, your efforts are much appreciated. Your video is very timely, I was only scratching my head today pondering which tariff to choose once my Solar PV and Giv Energy battery system are installed next month.
Ah, great. I hope your system works well for you and I hope the tariff you choose proves profitable.
Thanks Tim.
I pondered this myself, but I haven’t the time to actually think it through right now.
What a great community feel to find solutions to this energy conundrum.
I was a bit reluctant to do this analysis myself, but I'm glad I did. I hope it helps.
Thanks for the spreadsheet, very simple way of calculating and visualising monthly costs.
No problem, I'm glad you found it useful.
Excellent. Love a good heuristic, and putting the answer at the start (before the workings) is definitely the best way round.
Yeah, I figured a lot of folks would give up part way through the video so decided giving the answer within the first few seconds would help!
Thanks Tim and Kat. The video and spreadsheet were. A great help. Much appreciated. I ran my numbers through your spreadsheet and discovered that with the exception of one month, my tariff Octopus Intelligent Go was the most cost effective. The only other option was Octopus Flux which was marginally better on one month and I don’t have a GivEnergy battery so that rules Octopus Intelligent Flus (which was a bit better on one month). I appreciate the spreadsheet is not necessarily precise, but the clarity of the numbers matched my best guess and I’m happy not to need to jump tariffs twice a year with the reasonable certainty that it’s wise and not just lazy.
That's great to hear. I think you're right to just stick with IOG for the whole year. Saves the hassle of switching!
Many thanks for this. It’s very helpful. However, forced discharge does have an impact on efficiency as alongside usual inverter losses it takes more than a nominal amount to push out high discharge rates to the grid. There’s also an impact on battery longevity.
That's why it's a rule of thumb, not a thorough detailed calculation including all that stuff. The idea was to make it as accessible as possible to make it easy to apply. All those other details are secondary effects for those who want to fully optimise their decision; they won't significantly change the answer.
Great analysis and thanks for the video. I had just watched Gary's video, and when I looked at your chart I didn't immediately realise that it relates to the ratio of generation/consumption during the period of the tariff switch, i.e. in summer months the generation to consumption ratio will be a lot higher than the winter. I've not got my system installed yet (that's next week - exciting times!) but I'm researching to see what tariff to move to, and IOG was the 'obvious' one, until I saw this video. I've got info for our current grid use, so I'll have to take a punt on what I'll get from our 6.8kwp installation over the summer. I've also got shares in Kirk Hill wind farm with Ripple, so that's yet another curve ball! Great work, and thanks again
No problem. By the way, you should have estimated monthly generation figures from your installer, but if not you can use the PVGIS tool Gary mentioned to get a decent estimate instead. Then you can use those figures to compare against your monthly consumption. I hope that helps. And best of luck with your installation!
Swapped to Flux on the 15th. Made a simple spreadsheet to try to work out which was best for me. Didn't look at intelligent flux as I prefer to keep control of my equipment
Yup, that's totally fair. I'm very interested to see how Intelligent Flux works in practice. If I don't get on with it at least I can switch to regular Flux pretty easily.
@@TimAndKatsGreenWalkI tried to find out more details of the model octopus used but couldn't find anything. Is it a modelled on each customer usage and solar like predbat or just their supply / demand. Will be interest to see what you find out 👍
Been on Go since 2nd October. Not used any grid Import for a week. And hated watching export at 8p/kwh so this evening I moved back to Flux. (Not intelligent flux) Octopus have backdated it to midnight so 24kwh exported today at.18.5p (£4.44) rather than at 8p (£1.92)
Too late to do a force discharge between 4-7pm.
There's always tomorrow 😊
Ah yes, I'm starting to see a fair bit of export too, so the time does feel about right to switch.
Thanks Tim, Very informative video and very useful spread sheet. With my parameters in the spreadsheet it confirmed I should change from Go to Flux which I've just done. A suggestion of a small mod to the spreadsheet. Change the fill colour of the Tariff prices box columns to the same coulour as the trariff headings in the table below. Regards David.
Good stuff. I'm in two minds about your suggestion for the colours, as I want all input cells to be the same colour to make it clear that those are the ones that can be safely changed by the user (i.e. the light purple). I felt that the vertical alignment of those tariff prices with the tariffs below should be sufficient to make it clear what prices refer to what tariffs but I can see how that might not be quite clear enough. I've compromised by adding an additional row of tariff names above the price input block, so hopefully that satisfies both requirements for clarity.
Thanks Tim. Very much looking forward to videos sharing your experience with IOFlux.
Having a bit of trouble switching at the moment but hopefully Octopus can sort it soon.
Thanks Tim. Very helpful. Best regards Martin
No problem, glad I could help.
Interesting to see how close Go and Flux are. Thank you. Plugging in the numbers for my 4 kWp system Intelligent Flux would save me £20 a year. Using Go for four months would save around £35 a year. Not that I can get either tariff at the moment!
I look forward to seeing the reports on how Octopus use your battery. I set my system up to force export 18:00-19:00 every evening during the summer. If that does not happen then Flux is likely going to work out better than Intelligent flux for me (assuming they even expand to support other battery systems).
Absolutely, I'm super curious to see how it works in practice. You can be sure there will be a video to follow, explaining what I find!
Another great video Tim.
I did this analysis about a month ago to compare IOG with Flux, using a modified version of your COGS spreadsheet. For me, it suggested Flux would be better for June and July only and this is confirmed with the 1.4 rule.
However, I suspect the Flux rates will drop further in July with the next price cap change, so even that may be optimistic.
I'm sticking with IOG throughout.👍
Yes, indeed, every tariff change will require an update to this "rule". I'll probably have to issue an updated video each time!
Just one point on solar generation, any solar generated will always be used in the house first and any excess used to charge the house battery or be exported, you cannot actually export all your generation even though you have a battery, you need to set the battery to force export to compensate. Our Powerwall does this automatically, it simply works out we have spare battery so exports this, it ensures the house still runs off the battery until 11:30pm.
Your calculations are very useful and I think confirm my decision to simply remain on Intelligent Go all summer, the three cheap hours overnight are not long enough or cheap enough to charge our EVs and our 15p export rate is fixed till next January, there is always a possibility this will change in July if prices continue to go down, so sticking guarantees this rate next winter.
Yes, I did mention that you'd have to force export some battery to compensate for solar being used by your house (in the part where I talk about my assumptions), although I didn't explain it particularly well. As long as your export rate is higher than the off-peak import rate (modulo conversion losses) this is a good strategy regardless, as you are doing with your Powerwall, so you'll probably be doing a bit better than my simple calculations suggest. I think sticking with IOG all year is a decent option for a lot of folks, actually, as Flux and IOF are only really better than IOG when you have a bigger than average PV array.
Thanks for your data & video, you have more clearly defined my own looser calculations with my own battery setup. I have some differing characteristics, but the base data is similar enough to draw the same conclusions. Thanks for doing the hard work 👍 intelligent Octopus Go would give you extra (6hrs) overnight cheap rate window as a minimum of course, just need to update smart meter.
No problem, I'm glad you found it useful.
Great graph at 15mins!
Why, thank you. I was pretty pleased with it, I have to say.
This is exactly what I needed to know in order to decide when to switch tariffs! We are on Flux but have an EV now (Also Givenergy charger so intelligent Go not an option), so needed to think about when Intelligent Flux is better than normal Flux. 1.25x solar seems to be the inflection point.
Excellent, I'm glad this is useful for you! I'm hoping Octopus will get the GivEnergy EV charger integrated into Intelligent Go sooner rather than later. I might chase them up and see if they have a timescale planned.
Thanks, Tim.
You're welcome.
Very very helpful. Wish octopus had calculators for this stuff to help people choose.
You know, I might just suggest that to them. It's definitely gotten to the point where the choice is a bit overwhelming, for sure.
Thanks again for another great vid! I don't have an EV, my system is GivE and PV's, recently installed end of Jan 24. I moved to Go Lite as soon as I could with export rate of only around 8p. Decided to bite the bullet and change my tariff to IOF, be aware that I was in to my 3rd week until the switch was completed. Had to call Octopus to chase the switch, very odd since I was already exporting with Octopus via Go Lite. Anyway, the switch was made on 19th March. My peak export rate is 35.5p (4pm-7pm) and std rate is 26.6p (7pm-4pm). Something a bit odd is happening when I look at my tariff export card in the GivE portal. If I take export figs on 20th March, I exported a total of 8.9kWh but only 2.7kWh was exported during the peak rate, 3.85kWh was exported between 2.30pm and 4pm, 1.3kWh between 7.30pm and 8pm and the rest exported during the day outside the peak rate! Similar details have happened on the 19th to 22nd Mar too. My assumption when I switched was that almost all of my export would be within the peak rate. I have reached out to Octopus a few days ago to explain, still awaiting a response.
Yeah, that is odd, I'd also assume all the force exporting would happen between 4 and 7pm. Of course you will be exporting some excess solar outside of the peak time so maybe that's it? Look at how much of the export is from the battery vs how much is from solar. You might find the battery is only exporting at the times you expect.
good point
Good video. Switched to Flux from Go on 18th March 2024. Octopus immediately switched the import to Flux but the export can take up to 14 days so stuck on 8p export and cannot discharge between 4pm-7pm for the 28.79p per kWh.
One thought for your calculations: We have a 6Kw inverter and a 7.36pwh solar array the generation has been hitting 8.5 kWhs peak over the last week but once the battery is full is clipped to 6kWH. If your inverter is small you are losing out on some generation which is free and can export earlier in the day when the battery is full.
Or not AC charge if you have a hybrid which can charge the battery with what would have been clipped.
The idea was to keep the calculation as simple as possible. Adding in clipping would introduce significant complications so I ignored everything along those lines to streamline it, sorry about that. I doubt it would significantly change the broad conclusion though, if it's any consolation.
I *don't* (yet) have enough battery to power the house all day. Just putting in last year's actual figures for consumption and export, ie breaking one of the assumptions, reduced the Flux (we're not eligible for Intelligent Flux) suggestion to just two months, May and June.
So I modified the sheet to include percentage of import according to rate (the two IOG rates). Not ideal of course, given several of the variables, as well as not being able to find rates for Go, Cosy or Intelligent Flux, but I don't s'pose those would suit anyway. It did bring the monthly cost column for the tariff I'm on (IOG) much closer to what we actually paid, so it seemed it might be at least slightly useful.
Just that modification didn't make any change to the cheapest-for-me tariffs, still suggesting Flux for just May and June.
Yeah, if it's reasonably close that's good enough, really, as there are so many other things that can shift it one way or another. If the choice between two tariffs is marginal then the choice isn't super important. It may not even be worth bothering to switch for just two months of the year, and stick with IOG all year.
I am on Octopus Agile definitely saves me a lot.
I'm not brave enough to try Agile just yet. Maybe one day.
Only had my system installed in December (6.5kwp array and a pw2) Factoring in the saving sessions march will hopefully be the 1st month we have a negative bill, and thats on IOG with a model x which isnt exactly the most economical of EV's
So looking forward to seeing how it performs over summer.
Yeah, Summer feels great when you start seeing those negative bills. Bring it on.
Thanks for a great channel!
Oh you
Thanks, Great video!
No problem, and thank you for the super!
From what I've heard, Octopus don't make particular effort to export much during peak rate with Intelligent Flux - they may export quite a lot of solar directly, rather then storing it in the battery. So maybe only a small fraction (0.1, 0.2 ?) is exported during peak. Perhaps separat that out as a different input parameter ?
For the other tariffs, surely how much you can export during peak rate is dictated by battery size - in midsummer, you can't expect to export 20kWh in 3 hours from a 9kWh battery, for example. Any consumption during that time isn't exported, and you need to hold some back for evening, to avoid importing at day rate. But in the cooler months, you might be able to fit most of the generation into your battery for export during peak rate. So perhaps model it as,say, up to 6kW per day exported during peak rate, and the rest of the export at day rate. (On the longest days, there will still be some PV generation during peak rate, to complicate the modelling further.)
The point of this video was to keep it as simple as possible, that's why I don't have loads of input parameters and make some broad assumptions. I feel there is more value to getting a "reasonably good estimate" for a lot of people rather than getting the perfect value for the small number of folks willing to model all the tiny details. By all means take a copy of the spreadsheet and make you own additions, however. Regarding Intelligent Flux, watch Gary's video where he explains in more detail how Octopus manage the battery charging and export.
I’ve been enjoying playing the Agile import/export game for the past few months - not sure I’m willing to give away full control as HomeAssistant & PredBat running well. Likely Flux could be better for me. Interesting rules of thumb 👍
I've not been brave enough to try Agile. Maybe one day.
I was wondering about Agile too - just about to try and look up if Octopus allow Agile import and fixed 15p export...
@@SimonApperley I found this recently, it's pretty handy: octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/
The short answer is, yes, it seems they do!
@@TimAndKatsGreenWalk I wasn't brave enough to switch to Agile until the negative plunge pricing this week, changed about 2 days before it and I've already saved about £20 in a week, it's silly how cheap it is, it's compatible with all chargers as well, if you can set a price cap on your charger and it pulls octopus rates, it'll charge at whatever the cap is and below, I set my Ohme to charge at 0p and I got paid to charge my car, admitedly it was only 30p, but I got 40 odd kWh and 30p profit, this week I've averaged 21kw daily at an average cost of £2.35 a day, which works out at about 10.25p/kWh, no solar or batttery storage, just EV and Agile.
1:24 watching this while we have high winds and hail in Yorkshire 😂
Lol. I'm sure you'll have one or two sunny days at some point.
@TimAndKatesGreenWalk Thanks for your efforts with this video. I have a Tesla so currently on IOG, but I only very rarely charge at home (free charging at work) so I'm a pretty unusual case.. I wonder how I can maximise income from solar export over the summer.
It's a little tricky to work out my usage as I generally charge the batteries fully in the cheap rate and then discharge them for export at the end of the day before charging again.
If I look at the Octopus app and my Growatt Inverter app, I can see that in 2023 I Imported 10000kWh, and I exported 6000kwh, my solar generation was 6000kwh.
I'm not sure where that leaves me... 🤔 🤷♂️
It sounds like sticking with IOG all year is not a bad choice for you given those figures. You might find a couple of months over the Summer you'd be better off with Flux, but probably not by much. If you have your estimated monthly generation and consumption you could plug your numbers in to see. In either case, charging cheap and exporting higher, as you're doing, is going to be beneficial.
Thanks for getting back to me. It seems to me that many of these kinds of videos and spreadsheets don't look into the possibility of dumping stored energy to the grid at peak rate, and maximising profit from battery and solar installations. Just converting total usage and total generation to various tariffs doesn't take into account the possible behaviour changes that could be made to maximise profit.
I'd like to explore this myself but haven't got the Excel skills.
@@themorfill yes, force exporting will certainly change the equation a bit but for this particular video I had to make some broad assumptions to keep the calculation as simple as possible. Although, by force exporting you'll always get a slightly better result than my spreadsheet suggests so it can be viewed as a conservative estimate.
I think you need to look at Octopus Cosy - it's available to anyone one with heat pumps and offers two off peak periods at times when it's more useful: 4-7am and 1-4pm. For us, this usually means we are exporting at Peak times and never importing then. Things are nowhere near as simple is your assumptions make it though, for instance if our solar panels pointed more westerly we could be selling directly to the grid at peak value. Whereas our SE facing panels will have the battery charged to 100% by 10am and then we have to sell at a low rate. Battery capacity and Max Charge/Discharge rate, also makes quite a difference in the calculation.
Take a look at the spreadsheet, I added Cosy to it after this video. If you've got solar and battery, and an EV (so you can get Go or IOG), then Cosy is beaten by Go/IOG in most situations over Winter due to the significantly lower off-peak import rate you can get. And is beaten by Flux/IOF in Summer due to the better export rates those tariffs can get. If you only have a heat pump and don't have a battery or EV then Cosy is a viable option, but as soon as you add those other things it becomes less attractive.
Interesting and I like your idea of trying to produce rules of thumb that would suffice instead of doing detailed analysis. I was looking at my own consumption and generation data in Home Assistant and I’m not yet at parity on the two, so confirms my thinking its not yet time to switch but its getting there.
I’ll have to do some massaging of my data to work out my historic consumption which I don’t easily have. Have solar generation but last year I changed supplier and only got export setup in August and Home Assistant in November. Unfortunately the givenergy portal data is very inaccurate for multi-inverter setups.
It would have been really useful if you’d covered non-EV tariffs as well like Cosy, Tracker and Agile. I’ve done a rough comparison of Agile vs Flux and think based on last September data that Flux is only about £5 a month better off. More analysis needed …
These are the tariffs of interest to me, and probably most folks with solar setups, so I decided to keep it focused rather than making the video too long and complicated by including other tariffs. There are too many now!
Hi Tim, thanks for another informative video - I have been pondering this over the winter and for me Intelligent go seems best. I did wonder about your assumption though regarding for ed exporting a days worth of usage from the battery - my battery can power my home whilst all solar is exported, so no assumption required - is this not possible with the givenergy system?
You know, that's a good question, I do need to test that myself at some point, I'm not entirely sure. That certainly would make life a bit easier.
I would love to be on IO Flux for the summer. However I have dual AC3's and apparently you can only have 1 giv inverter to join IO Flux. 1 device, 1 inverter and multiple batteries are fine. Same issue having dual zappi's and switching to IO GO.
Oh really, that's interesting, I hadn't considered that. That is a shame.
New changes to Cosy tariff coming. New video? 😉
My own spreadsheet takes my use and calculates my total use in each of the 48 half hour time periods and applies the tariff rates to estimate a cost (or uses the average half hourly tariff rates for Agile).
Yup, I'm thinking I probably should do an update for this soon.
Hi T & K
I see ASHP get a lot of publicity and you never hear about modern night storage heaters. Perhaps a comparison might be an idea. I have 4 Dimplex Quantum RF100 heaters and a Nissan Leaf which does not get much use. I use a max of about 250 kWh / week in the depths of winter then of course it tails off.
I am on Octopus GO at 9p off peak.
I have 3.5kw of solar plus iboost and An 8.3kwh GivEnergy battery. Plus FIT. I use well over 90% off peak power and no gas. I also have a Mixergy hot tank.
A few people have asked me about storage heaters and how they compare to heat pumps. I should do a comparison video, you're right. My answer is that heat pumps are over 3 times as efficient as storage heaters, so use a third, or less, of the total electrical energy to get the same amount of heat out. That's why they're so good. Storage heaters can cost a similar amount to run as heat pumps, assuming you can charge them up with off-peak electricity. But if you combine battery storage with a heat pump you can also at least partially run your heat pump using off-peak electricity too (in fact we have used only off-peak electricity for our heat pump system since mid January, although we have 14.7 kWh of battery storage), so then a heat pump becomes significantly cheaper to run than storage heaters. Of course, if you can't install a heat pump, for whatever reason, storage heaters are probably the next best thing.
@@TimAndKatsGreenWalk so how does my weekly usage compare with yours?
@@richardspencer6695 I show my monthly data in the video (and in many past stats videos), if you're interested in comparing, although I caution you to not draw any conclusions from that. Doing those sort of comparisons is pretty meaningless as lifestyles and houses are all so different.
How about comparing agile to flux for summer, which one? Currently on agile.
Agile is too volatile to create a simple formula for, unfortunately. It was beyond the scope of this video, I'm afraid.
@@TimAndKatsGreenWalk yep it is difficult on these vids as of course last weekend we had a good one and basically used 90kwh for free but you cant model. Not everyone is like me with ADHD and checking the data/prices every few hours ha ha If you want a set up and go tariff I think IOG is the best with all the caveats on EV usage and shiftting usage to night.
@@ianrob4760 I'm considering doing a follow-up video for folks who don't want to keep switching every six months. I would agree that in that case IOG is almost always the best choice for most folks.
@@TimAndKatsGreenWalk yep, I should state I work in IT doing data monitoring so just waiting for this to go even further - czcams.com/video/g-RQ0dOPTtc/video.html and of course for some people this is just too much to handle, thats normal.
For Flux have you considered what happens on days when you have low or no generation if you're on GO you don't have to worry or does the Intelligent Flux do that for you. When Sunday roast is on a low generation day I sometimes use most of my 15 kWh batterry
The sunny days more than make up for that. As I said in the video, this is a rule of thumb, if you want a fully detailed calculation you'll have to do that yourself.
Thanks Tim, very instructional. Point 3 in your assumptions says all your solar generation is exported.
Does the fact that I cannot run the house off the battery and simultaneously export my solar at the same time mess things up a bit.
i.e my battery will always charge from solar until full, only then will it start to export excess while at the same time feeding the house, I can not separate the two. or is that what you mean ?
Yes that was the assumption I was least happy with as well. I guess the counter argument is that when you are using solar to power your home you don’t need to drain the battery and so you don’t need to import as much overnight at the cheaper rate. But it does skew the figures
That assumption works out to be valid if you force export some of your battery too, equivalent to what your house used from solar (excluding any solar that went into your battery). And that only matters for Intelligent Go, the other tariffs aren't really affected by that assumption because of the relative import and export rates.
Very helpful - I’m on Flux but I’ve only had my system since Oct last year so I don’t have a full year of consumption and generation. As generation starts to rocket up, like you I’m in 2 minds when to take the intelligent plunge! Programming the battery is a pain in the @ss. I was surprised that in a cloudy/sunny/rainy day, we generated 24kw from 12 south facing panels - a record for me since installation. As you say it may be easy to switch back with limited fuss. So your advice is go for it from April 1?
Well, I'll be switching early April, and it sounds like it'll be about right for you too, but you can always check using your estimated monthly generation. You should have that from your installer or else the online PVGIS tool is very good for that too.
Thanks, that's very helpful. I started the process but I'm getting a couldn't connet device error message. "Make sure that 1) your device is fully set up on the GivEnergy app 2) Your battery is connected to the internet 3) username and password is correct" Are 1 & 2 the same? My Give app is fully functional but is there something else I should be doing? Have you tried to set this up too? @@TimAndKatsGreenWalk
You need IO Go I can't Flux getting anywhere near it once you've taken into account charge/discharge losses and wear and tear on the battery. Also the small cheap rate window means the house battery would never get a full charge overnight and likewise for the car as when I use it I tend to come home with it empty and want a full charge.
I agree, the 6 hour off peak import window with IO go gives much greater opportunity to fully charge home batteries and EVs, it also means the home battery only has to cover 18 hours. Additionally, the 18 hour period where exports generate 15p (7.5p ‘profit’) means variable solar generation matters less and the absence of the need to force discharge at certain times are big bonuses which are hard to quantify on a spreadsheet. I think system adaptability and tariff flexibility are key enablers to be able to adapt to future tariffs which will surely be offered in the coming years.
If you've got high generation the exceptional export rate is what wins it for Flux (as demonstrated). That blows away any losses or wear and tear.
@@TimAndKatsGreenWalk , it depends how you define high generation. Over the last 4 years I’ve generated 8000kWh per year on average. My consumption is 15-16MWh annually, so against your 1.4 criteria IOgo is indeed the best option. My point is that with higher consumption / generation, your perfectly valid assumption about 100% battery use and 100% solar export can be constrained by the shorter windows of off peak import rate and peak export rate. Therefore the shorter import window with Flux can constrain the ability to fully charge a battery that can support the whole house throughout the day.
I was surprised by Intelligent Flux in that it actually hardly uses the battery; it discharges it at full speed in the peak period but other than that it doesn't discharge at all, and it either charges from solar or very slowly during the afternoon if it's not sunny enough. It must be one of the best ways to look after your battery.
We were on it briefly last autumn but will probably be back on it when it gets a little bit warmer.
@@philhimsworth that is interesting. Also not what I would want as my battery would be empty by 18:30.
Interesting to hear your comments at 9:30 about force exporting as I havent worked out yet how to run the house only from the battery (if thats possible) without solar first topping the battery up before export starts (Ive got givenergy also) and so I was toying with the idea of a forced export from say 2130 to 2330 to near exhaust the battery (or maybe exhaust it) before forced import starts at 2330 to fill up the battery again. I take it this is the scenario you were outlining? Obviously you do lose a little bit through the inneficiency of going via the battery before you export.
I'll have to start monitoring what the battery % is in the late evening and also what the export rate the battery can do is (I think its 3.6 even though Ive gota 5kW inverter, but not sure but even with everything ramped up asa test in teh hosue I think the battery maxxed out at 3.6)
Looking at your graphs, staying with Intelligent Go also seems simple and avoids the hassle of changing tariffs a few times a year albeit at the cost of giving up some money.
My install is new (as is IO I only switched yesterday ! ) but i reckon I'll be on the borderline of IO and Flux, so again sticking with IO seems an easy route. Plus, although my usage is ~6000 kWh compared to estimated production of ~9000 kWh, half that consumption is the car which is at very predictable off peak times so that maybe skews the calc back to IO?
Anyway thanks for this outline.
Sticking with IOG is a pretty sensible option for a lot of folks, I think. Although switching tariffs is really pretty trivial with Octopus, it can be done almost instantly in many cases.
@@TimAndKatsGreenWalk after the hassle I had connecting with my charger to set IOG upI'm inclined to leave well alone LOL
@@Joe-lb8qn that's fair enough.
I'm limited to 4kwh on exporting the local transformer cannot cope unfortunately. As more houses get solar in the village it will only get worse.
Yes, that is an issue. We're the only ones with solar in our local area so no problems for us right now but it'll be interesting to see how that changes as more folks get solar.
is it possible to set the givenergy up to not pull from solar? your assumptions about ‘all house load can be covered by battery’ fits me, but as I use some in the morning, the battery will always first top up and only export the excess. So the battery is never really ‘exercised’. Does that matter in the end or does it all sort itself out in the end?
If you force export a bit from your battery, equivalent to how much solar your house used during the day, then it all works out as if you powered your house only from the battery. You can set your GivEnergy battery to charge from solar only, but not grid only, it seems.
Hi T & K
Two questions, can I go on octopus flux if I am already on a feed in tariff? And how do modern night storage heaters compare with an ASHP for cost and power usage?
I am on octopus go and my car does not get much use being retired.
I believe that you would have to give up the deemed export part of your FIT in order to get the Flux export. And have a smart meter. You should be able to keep the generation part of your FIT though, you'd only have to give up the deemed export part. As for storage heaters, they will certainly use more total kWh of energy to run than a heat pump (probably three times as much), but if you heat them overnight at low rates then it will probably work out similar cost. However, if you have home storage batteries and solar then you can use those to help support a heat pump while it runs during the day (as long as your battery is of a decent size), in which case the heat pump becomes a lot cheaper to run, as you can effectively use off-peak electricity while also using a third of the energy compared to storage heaters.
Sorry to ask a basic question but I'm quite early on my journey. What is the best way to work out the consumption?
I had panels and a battery installed late summer. Before that I worked away from home alot and then retired so my bills are a bit all over the place. On the app I have PV, Load, Export, Import, Discharge & Charge.
I wanted to get through my first winter to see what performance was like, pleasantly surprised since mid January. One battery is enough for more than a day but I will get a second.
It sounds like Load is what you want. It should be roughly the same as your grid import plus PV to the home (if your app breaks down the PV in that way).
@@TimAndKatsGreenWalk Thanks Tim, had a nose round and found I can customise monitoring parameters. I wouldn't had thought about it if I hadn't seen this video 🙂
Hi Tim,
1.4? Isn't it funny how Pi turns up everywhere? 😂
Your predictive graphs look similar to my estimates predicting April and October being the tariff swap over points.
I was on Flux over summer and have survived on Intelligent Go over winter funded only from the summer surplus export banked into the account which is only coming close to zero now when I'm getting to the April break even point again - so it looks like it's proved possible to have zero bills over the whole year.
Over summer I was not AC charging the battery on Flux so it was entirely supported by PV in maximum self consumption mode. Had I AC charged I guess that would have gone out as expert when the battery got to 100% which is more likely earlier in the day before the peak 4pm to 7pm time. I didn't Force Discharge and only let that happen naturally on sunny evenings. So, I suppose there's some further advantage to be had possibly.
Oh, and although summer running comes from PV and battery, on the coldest winter days I was running flat towards the end of the day with the heat pump load so I had some peak import.
It's all good stuff overall anyway! Interesting to see your estimates.
That's great to hear. Sounds like You've got a good strategy that works for you.
@@TimAndKatsGreenWalk I was thinking how it fits with your assumptions - so main differences being (1) no AC charge when on Flux (but that might not be best policy), (2) my battery runs flat in winter and (3) I think most export will be earlier in the day especially if AC charged as the battery gets to 100% earlier, so there will be well less than half the export in the peak time 4pm to 7pm - unless you Force Discharge.
So, is your presumption that when on Flux you always AC charge and Force Discharge so export is 50:50 split across the two export rates?
I appreciate you are trying to keep it simple so not sure if that helps or hinders.
@@johnh9449 for Flux it actually doesn't matter whether you charge up overnight or let the solar do it, since the overnight import rate is so similar to the day export rate. The assumption of 50% peak 50% day export would be affected, yes, but you can adjust that in the spreadsheet based on what you typically see in your data.
Hi Tim. Octopus won’t do intelligent flux for Powerwall 2. I have gone back to Agile from Flux as I can’t see the point of the daily import and export prices being almost identical. Am I missing something? Chris Mc. Only batteries, no ev
Intelligent Flux is only available for GivEnergy systems. Go check out Gary's video comparing Flux with IOF, that's a good summary. The main benefit is the huge export rate, so if you generate a lot you'll get more paid back to you than if you're on regular Flux (as shown by my chart).
Tim. Early in the video you talk as if you can make the battery run the house and the solar go direct to the grid. Mine only goes to the grid once the battery is full. Is there a GivEnergy setting to force this?
I was wondering this myself. In practice you can achieve an equivalent effect by force exporting some of your battery during the day, but that assumption was more about making the calculation simple than the practicalities of it. Having said that I shall be experimenting with the settings to see if it's actually doable.
@@TimAndKatsGreenWalk thanks. We enjoy your channel. Unlike a lot of your followers I’ll be glad of the day when Octopus just controls it all for me (solar, charging, import & export), and I can forget about it. 😀
@@richardeskins haha! Yes, I think the idea of IOF is actually a really good one for folks who don't want to do all the fiddling. It's a perfect plug and play tariff imo. I'm keen to see how it works out for me over the Summer.
Strange you haven't got new rates yet. I got mine about a week ago from octopus for regular flux. Think the assumptions stated in video are more or less on the money in that day export and import are close, within 0.3p per kwh.
I only got notification of the new Go rates, since that's the tariff I'm currently on. They didn't tell me the new rates for all the other tariffs. Good to know my assumptions aren't too far off though.
@@TimAndKatsGreenWalk Ah that would explain it 😀
Tricky. Monday - Thursday 8-5 and Friday 8-2 use 8000kwh per year and produce 6000. Battery present no ev. However, we don’t work at the weekends. I was thinking of just using intelligent flux but maybe just octopus go all year might be the better option. I mean in summer basically 4 days per week oct go is probably better and 3 days per week summer intelligent flux. Winter oct go all the way. Just installed so no figures yet
You should have an estimate of your monthly generation from your installer so that'll help. Otherwise there's a good online tool called PVGIS where you can get a good estimate instead. In either case best of luck with your decision!
@@TimAndKatsGreenWalkthanks Tim. Annoyingly my provider hasn’t given me the monthlies. I can estimate it from our other work site which has a 19.5kwh array (no battery) from 2016 which was a great idea as just got the FIT also. Anyway I think that (based upon the graphs and educationally guessing) the intelligent flux (for ease) is probably best for the summer april - mid October and then October go. I’ll keep an eye on it and see what they do with the battery! Really wish intelligent oct was a battery non eg option. The summer is probably just over 1:1 and with lots of export days that probably swings it and the tariffs are all fairly close around that ratio… v interesting anyway and thanks a lot 👍👍
@@simoncove1 yeah it's complicated! At the end of the day having a solar system will always be beneficial, so as long as you find a tariff you're happy with it's all good.
If I force export, does octopus pay 15p no matter what time? thinking from an automation pov could you schedule your battery to force discharge to eg 10% at 10pm or so, so you’re safely not going to pull any peak grid, then recharge overnight?
If you're on Intelligent Go the export rate is indeed 15p regardless of time, so yes, you could force export at 10pm, as you suggest.
Hi Tim, not sure which EV car you have but does Octopus Intelligent Go not allow direct connection regardless of which EV charger you have, we have just bought an BMW i3S, had Easee wall charger installed and have 5.4 Kw array, GivEnergy Hybrid 5Kw inverter with 9.5Kw Battery.
I was able to join IOG and use the 7.5p overnight tariff, I’m currently waiting for my export tariff to change to 15p Kw.
Your graph seems to make IOG the best all year round tariff for your circumstances.
I find your channel very informative, keep up the good work.
Unfortunately IOG is only compatible with certain EVs, or EV chargers. In other words you can either have a compatible EV, or a compatible EV charger (or both). If neither your EV nor EV charger are compatible then you can't use IOG. Sadly we currently have neither. IOG would certainly be best for us over the Winter if we were able to to get it, but over the Summer Intelligent Flux would end up paying us slightly more (i.e. more negative on the chart). If we didn't want to switch every six months then IOG would be the best single tariff for the whole year. I'm hoping we'll be able to get IOG once Octopus include the GivEnergy EV charger in their list of compatible chargers (before October, I'm hoping!).
@@TimAndKatsGreenWalk I’m sure the GivEnergy charger will be adopted shortly as they are certainly one of the main players in the renewables field, I thought about the GivEnergy charger myself but opted for the Easee as I wasn’t too concerned about the smart feature as I’m not looking to use solar to charge the car, certainly not when you can get 15p Kw EXPORT and charge during the off peak, it suits our current circumstances as the i3S only has a 42Kw battery which can easily be charged during the 6 hour window however when I change my car next year our opinion might change if we go for a 2nd EV with a larger battery, we might require the smart facility of IOG at that point.
As it stands we are having conflict issues between the 3 apps (BMW, IOG & Easee) so have disabled the smart feature in OIG and only use the BMW app to schedule charging in the off peak period.
Yes, I'm sure the GivEnergy charger will be supported soon. One thing to bear in mind is that to be on IOG they need to see you do a charge using that system every now and then or else they might kick you off the tariff. So you might find turning off the other two apps and letting IOG do the charging is the better option. Presumably Octopus is taking control of either your car or charger in any case, so you can set the other app to just charge all the time when connected (and the IOG will only provide the juice when it chooses to).
@@TimAndKatsGreenWalk cheers for that, I’ll keep an eye on my tariff and see if octopus kicks me off it, I tried all sorts of permetations with the OIG app and couldn’t get it to work as intended, looking at various EV forums and it seems others are having a similar issue regarding the intelligent charging.
I’ll investigate further as I’m sure this issue will be down to user error and see if I can have it communicate with only the OIG app.
@@TimAndKatsGreenWalkNot hearing much positivity on the Fb forums re GE charger..
Hi Dave, not quite related to this, but the figures of Givenergy app and portal are higher than octopus state in ‘my usage’ figures for export and lower for import. Only a few kilowatts over the 3 weeks my system has been on and 10 days exporting but wonder if you or others had similar and how to resolve.
Yes the fix is very easy, you simply have to learn to ignore the givenergy figures. 😂
Joking aside, the givenergy figures are 5 minute samples that are then extrapolated to be what happened for the full period of time. So if you have the kettle on at the 5 minute mark, it’ll look like you had the kettle on for the whole 5 minutes. Likewise if there was a cloud going overhead and your solar was low, the 5 minute data will be at that low level.
Its awful but its just the way the givenergy portal works.
If you want more accurate figures you need to do something like install home assistant and get the data off your inverter directly
Done that with my Sunsynk inverter using modbus and rs485 with an ESP32 board connected to a pi4. 3 second refresh interval 😊
Reflecting further, surely the octopus figures would be lower than the ge import info
My GivEnergy figures are pretty close to what Octopus say, although certainly I'd take the Octopus figures as the truth since that's what your bills are based on. It's Tim by the way, like in the channel name 😉
Tim, with the 1.4 times rule, if my home uses 5,500kwh and my solar will generate 3,000kwh, then am I right in saying that my case doesn’t satisfy your rule? Thanks
If you break it down into months you may find some months where you generate more than 1.4 times your consumption, and some less. Worth seeing if you can find that data.
@@TimAndKatsGreenWalk Thanks for the info. We just had solar installed in December, so I'll collect data in this first 12 months. On a positive note we're on Octopus Intelligent Go, which by your model looks like 2nd best, so happy to go with that for the first 12 months. Great video - thanks Tim!
@@bloodynorahvan2203 you should also have monthly estimated generation figures from your installer. If not, you can use the online PVGIS tool to get those estimates instead. That should give you a bit of a headstart and save you waiting a year.
Does seem strange that octopus 🐙 has giv energy battery as the only one that works with intelligent flux but dont have their charger compatible with intelligent octopus go.
I'm sure they'll get there eventually. Hopefully before next Winter!
Charger is relatively new. I'm sure they have hundreds of devices to integrate into their systems. So many EV chargers out there. Must be a big job.
Confused why would anyone not use the Octopus Outgoing Fix rate which is 15p/kWh. That’s what I now have with IOG as my import tariff
You can't get that outgoing tariff for the other import tariffs mentioned in this video.
Like this: octopus.energy/help-and-faqs/articles/which-export-tariff-can-i-combine-with-my-import-tariff/
@@TimAndKatsGreenWalk But that's not correct according to the image (and my current setup). Outgoing Fixed at 15p is compatible with Intelligent Go. I force-charge my battery at 7.5p overnight and then export all my solar during the day at 15p - have been doing so for almost a year now.
@@Rob-ct4xp yeah, that's what I said. You can get outgoing fixed with IOG but not the other tariffs, i.e. you can't use it with regular Go or the two Flux tariffs.
Hello Tim,
Can you use a solar diverter with Octopus intelligent Flux??
You'd have to find a way to prevent it from diverting during the peak period, while your battery is force discharging, but if you can do that then you could use one. Although in practice that's easier said than done, and you don't really gain anything since exporting to the grid is the same price as importing, so there is no benefit to solar diverting at all on Intelligent Flux.
I actually change the settings on my eddi to prevent soar divert during the Summer for this reason, as I don't want the eddi seeing my force export as solar excess, since I want that to go out to the grid, not into my hot water. The reverse of this, basically: czcams.com/video/tNPE2G4JPZI/video.htmlsi=GXu5MqCq0yMtS_fg
Ok, thanks for advice and all your content, very helpful. Still trying to decide on which Flux tariff to change to.
Hello Tim. You have a lot of interesting videos. You might be interested in what I have done. Firstly I've been a house builder for 40 years now retired. I have been a geek about energy. Our last house was 500 sq/m. We had a 12Kw wind turbine plus solar and we were making £7K a year. We were early with the FIT luckily.
Our current house - 8 year old is built to passive house standard. It's 400sq/m and the heating requirements for heating is 4Kw. We have a 7kw air source heat pump with underfloor heating.
Yes even a passive house needs some heating when it falls to zero.
We are all electric but have only recently installed 8Kw ( 20 ground panels) and 2 x 9.5 Givenergy batteries. You missed out COSY tariff from octopus. off peak 04- 00 to 0-700 and 13-00 to 16-00.
Not sure it's the best tariff. Our usage is about 20 to 24 Kw/hrs per day no heating on. And about 44kw/hrs for a few months over winter with heating on.One major problem is that the company that installed it quoted for an 8Kw inverter. But they only fitted a 5Kw inverter. Output and input is only 3.6kw. Turns out the 8Kw is 3 phase. I will have to sort this one out.
I'm trying to find out if they can fit a second inverter.
Our annual energy use is about 12000Kw/hrs
I'm still trying to get to grips with settings in the portal. Or just to set it to Eco and leave it. It's early days though.
I'd love to build a passive house one day. I'm not sure it'll ever happen but if Kat and I ever get the opportunity we'd definitely love to try. Yours sounds amazing, I have to say. I deliberately left out Cosy as I don't believe it would ever be the best option for the Summer (since this video was aimed at the choosing the best tariff for the Summer). These four are the ones most folks with solar are likely to be considering, I believe.
@@TimAndKatsGreenWalk You could be right about Cosy tariff. Just been listening to Gary does solar and Intelligent flux sounds good. I think that might be better. Still have to get my export sorted out first. Thanks.
@@davidgray2825 after your comment about Cosy I went and added it to my spreadsheet out of interest. It looks like it's never the best tariff (under my assumptions) with Flux/IOF/IOG beating it in the summer and Go/IOG beating it in the winter. I think the main benefit of Cosy would be when your battery isn't big enough to support your house load plus heating, so you can double charge it to help mitigate that. Anyway, it's in the spreadsheet now!
I understood that Octopus were making Intelligent Flux a fixed tariff for 12 months. So no switching just for the summer. Can you confirm?
As far as I understand it you can switch between any of their smart tariffs every 30 days, with the exception of the Tracker tariff. Take a look at their tariff terms of use, it may have changed since but that's what it said when I last looked at it a few months ago.
octopus.energy/policies/smart-tariffs-terms-and-condition/
If you want to be sure I'd suggest emailing them and asking directly. When I did that six months ago they said I could switch back and forth every six months with no problem.
Hi, I have solar but no battery, I store it in the car. What are my tariff options if I don't have a smart meter? It's not an option where I live.
If you don't have a smart meter your options are very limited, I'm afraid. It'd be standard tariffs from any supplier, so no time-of-use tariffs like Octopus Go, for example. If you can find any way to get a smart meter installed it really would open up a lot more options for you.
@@TimAndKatsGreenWalkThanks Tim & Kat, yep that's what I thought. I've had at least 3 meter changes over the last 2 years and they still can't get a connection. When you think how many connected devices we have all around these days it's pretty poor that many meters are still unable to connect. I'm planning on getting another electric car so I can make better use of my spare solar in the summer.
@@Bendydog ah, that's a real shame. I wonder what the problem could be. I guess you're quite out in the sticks? I believe smart meters rely on the mobile data network so if you're in a dead zone I guess that would do it.
I actually live in a busy town in Northumberland so when I moved in I didn't expect there to be an issue. I even contacted Greg Jackson directly and to be fair they have been very accommodating.
@@Bendydog interesting. I had no idea it could be difficult to get a smart meter to connect. It does sound like something that they should be working on to improve. Hopefully a solution can be found in your case. It must be very frustrating.
Just got eon next and have 7 hours at 8p on their EV tariff and if you are a customer they give 16.5 p export. Is that better? ❤
Well, you'd have to enter those values into the spreadsheet to find out.
I'll give it a go.. thank you.
Yes this eon tariff is slightly better than octopus intelligent go
@@serraios1989 it depends how much you import vs export. IOG has lower import, so if you consume a lot IOG will be slightly better.
@@TimAndKatsGreenWalk
You are right, it’s down to each one’s circumstances. Eon off peak time is 7 hours vs octopus six hours. I am with octopus and I have no plans to move to eon, but the seven hour off peak would suit me better to charge our two evs
The Generation column on your spreadsheet is white, implying we should not edit it. Is that right? I would expect we'd want to plug in our own expected generation figures.
Ooh, good spot I'll sort that, thanks Andy. Yup, should be an input column.
Done
for the lazy - just stick it on Intelligent go and leave it there? its best in winter and not massively worse in summer.
Yup, that about sums it up.
The title made me think you’d be cover electric and gas 😢
The tariffs on the thumbnail are all electric ones, though, so not sure how I could have made that clearer, sorry.