Is Solar Thermal Dead?
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- čas přidán 6. 09. 2024
- In this video I talk about why some people claim solar thermal is dead. Also I cover why some systems fail and why ours works seamlessly. Ultimately, off grid type solar power systems and other forms of renewable energy must be in our future, and permaculture is part of the solution.
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We have three twenty-tube panels on our house. They supply almost all our hot water needs, except for an overcast week here and there when a coil in our woodstove takes over. We're very happy with their performance. The downside: careful design is required, plumbing is required, glycol is needed as a working fluid if you live in a freezing climate, with a heat exchanger to transfer the heat to your domestic water.
If we wanted to generate this much hot water with photovoltaic panels we would need about three times the area. Having said that, heating water electrically is much simpler, with no moving parts. It just requires a LOT of square footage, which you may not have room for.
One more thing: every winter we still make significant amounts of hot water at minus 30C. As long as the panels are free of snow they work. Even a light coating of frost hardly affects them.
We're off-grid in Williams Lake, B.C. Canada
In the refrigertion industry they have a pipe insulation called armaflex which you can get with a hard outer surface to prevent birds from picking at it and prevent to sun rays from breaking it down I've used this a little bit where I live it works great
I got a plastic, hollow owl from walmart. I put in 5 lbs of aquarium rocks in it to keep it from blowing away on windy days. Works great! I spent total of $15. No more annoyance bird problems. My son named it "Owl Pacino"...
Interesting explanations on a number of subjects, but the answer is being totally off grid. We've been off grid for over 10 years and will never go back. When the power goes off down in town, we're the shining beacon in the hills above. Pumps run. The refrigerator runs. Lights shine in the dark. One thing not mentioned as a solar thermal advantage is that it's quite a bit more efficient to make water hot in the sun compared to even the most efficient PV panel. The overheating dissipation loop is a good idea, and something I don't have here, but we have our panels vertical, so the most direct sunlight takes place in winter (and I built the system specifically for radiant floor heat). I monitor the tank temperature with the differential controller, and my simple idea was that if things get too hot, simply cover a portion of the panels. ....I'm retired, so am available to the system most of the time, so manual adjustments might not appeal to everyone. As far as that foil and the birds, you've likely got the pecking issue fixed, but if not, build a plywood box over the insulated vertical plumbing run. A narrow vertical box won't weigh much, and windage shouldn't be a problem. Thanks for the video. I like to look at other projects and ideas.
Definitely not a dead technology...in fact it isn't utilized enough!!!! We are the only home in a community of 300 homes with PV and SHW...
I personally believe solar PV and hot water should be mandatory for all new construction at a minimum...and most additions should be required to install 50% of the home daily electric use in PV...
Behind every mandate (law), however good intentioned, is a gun pointed at your head. Good intentions do not justify violence. If it's the moral thing to do, it's the practical thing, meaning no threats are necessary.
Not gonna happen till anyone can go to their local box store and buy one off the shelf that meets the to-be-written code. The heat pump based units are quite efficient ... especially in hot climates since it basically supplements air conditioning as waste.
BeeFriendlyApiary What’s the science behind it and how do it in a cold climate like Washington state. It gets freaking cold here.
@@billiamc1969 Your comment is foolish -- have you ever had to maintained one of these systems? They are known to fail, not because good technology doesn't exist, but rather because people don't maintain them properly. Solar PV generally speaking is quiet and reliable. Solar thermal can also be reliable, BUT most people don't install the protections required to prevent the glycol from boiling when it gets too hot. As this guy says in his video he is using Solar PV to power his SHW pump which means it never fails even when the grid is off. And then he's got the 3-way valve as a backup which is very smart. Possibly charging people a small fee when they don't choose SHW would be a good motivator. But making it mandatory is going too far.
get some thin wall pipe split it and encase the insulated pipe , your welcome.
For the magpies - get a thick see through small plastic bag (sandwich bags are great), half fill it with water and hang it by string on the collector. They don't like the reflections it makes it scares them off. Same thing works for flies if you hang it in front of a window or door it stops them flying through
This was interesting, useful, and easily understood by non-engineers. Thank you. Excellent video.
You consider photo voltaic PV for domestic how water (DHW) as a part of electricity generation system part. I'm thinking hooking up 2-4 panels to a mppt tracker and hook them up straight to the heating element inside DHW tank, once that is heated up, into the thermal buffer tank. I heard enough from the people that have systems like yours to make an option that: heat exchanger, long piping, auxiliary pv for solar pumping, or big tank on top of the roof for natural convection.... For me PV is the way to go, considering i might install more in the future. I'll give solar thermal this: PV is only 20 percent efficient while thermal is above 95, which is nice.
I agree, especially in a cold climate like mine. 2022 modules cost 10% of ten years ago too, hard to beat.
I have a friend in the Wisconsin Dells. He runs a motel up there and has had Solar Thermal there for DECADES.
It provides RIDICULOUS amounts of hot water for the site. Two heated pools and a hot tub.
In late September, mid-October, you can hop in any of the pools at 9PM and they're still bathwater warm!
As for protecting the pipe.
Insulate it normally.
Get some larger PVC pipe.
Rip it up the length.
Stretch it around the main pipe.
If you haven't solved your magpie problem yet, you might consider black stove / engine paint. You can pick up spray cans of it at the hardware store, and it should handle the high temperatures easily. I don't know if it will stick directly on the aluminum though. You might need a high-temp primer first.
If that doesn't work, I'd be tempted to try 4" flexible plastic drain pipe. Cut a slot in one side so you can wrap it around the pipes. It doesn't have to be tight - in fact you may need an air gap depending on how hot your pipes are to keep it from melting. Cut it to length to fit sections of pipe, and keep it in place with plastic zip ties.
I've been thinking about one of these systems for my own home. I'd really love to dump extra heat into my house in the winter!
Cynthia Cantrell Have you done it yet?
I have a 60 tube evacuated tube array on my summer home in Michigan. It provides 100% of my domestic hot water in the summer. I have to cover about 30 tubes in the summer to keep from collecting too much heat. In the winter I switch to heating the house. The collectors keep the 2400 sqft home above freezing all but usually 5-10 days all winter, I drain the water system so freezing isn't a problem. I had planned to install a 2400 gallon tank under the floor when I built the house to have enough heat storage to ride through the real cloudy and real cold days but didn't. With more storage (only have a 120 gallon solar storage tank and a 50 gallon standard electric hot water heater) I have no doubt I could keep the house above freezing. The system has been running for 7 years. We are in a resort area with plenty of guests in the summer. We have had 14 people in the house taking plenty of showers and have never had to turn on the electric hot water heater. I have even challenged my guests to run me out of hot water. If I start running low on hot water I uncover a few more tubes. The collectors collect plenty of heat on all but the most cloudy days. With snow on the ground they collect about 50% more heat. My system needs 110 volt power so I have a expansion tank that keeps the system from purging when I loose power not ideal but it works. My collectors are on the ground so I can cover the tubes to keep from collecting too much heat. The system does heat the house if the system gets too hot, not fun on a hot summer day.
Wow! love to see your system! im also doing a DYI! and i make alota heat and also have to cover some panels
I've seen a bird deterrent that is like a number of springy wires with little weighted balls at the end. This messes with the birds wings, landing or taking off & they hate this worse than landing on spikes which irritate their feet. It does not catch or injure the birds, just taps into a primal fear...messing with your wings if you are a flying creature is beyond irritating.
I used a toy snake from my kids, that did the trick and scared the birds off my strawberries.
Interesting idea!
Many excellent points raised............thanks. you could get that plastic spiral wrap used on vehicles looms and hoses.wrap round and throw on a few zip ties.
You could just paint the foil so it's not shiny anymore.
Thanks for the ideas!
The foil is there to reduce emission losses in the IR spectrum. If you paint it you are emitting again. Just build it in to a box a clad it with roof paper.
@ferkemall cut a plastic tube along and fit it above the tube.
@@per.kallberg Is it not the other way around? By painting it black it will not reflect the light cumming from the outside and will in fact absorb some of it. Its gets hotter and dissipates less heat from the inside out. What i'm i missing?
MaxSantos the “paint it black” was to not have magpies take the shiny stuff.
You are correct in that black absorbs more but it also emits equally more. Since the vacuum tubes creates very hot water even when the sun is not shining the emissions is a bigger problem
If you use PV Solar for heating, you could store heat in a hot water tank instead of storing electricity in batteries.
Dan, this is true. Electricity is a high-grade energy whereas hot water is a low-grade energy. If you can afford it, batteries are a much better way to store excess electricity. Dumping electricity into a hot water tank is a good option if you are off the grid.
The largest energy consumption of any dwelling in high Northern or Southern latitudes (>42°- 45°) is by FAR heating. Even in very sunny/warm climates hot water demands represent a very considerable proportion of the energy mix. It makes ZERO sense to rely on Solar PV, at best an 18% efficiency producer of electricity from the solar energy available, to produce heat energy. FAR more effective to collect the heat directly. There are THREE basic solar heat collection technologies available. I'm excluding air and ground heat pumps as they do not relate directly to solar power except as mentioned below.
1. Direct solar heating of simple pipework containing a heat transfer liquid (least efficient - think of a hosepipe lying in the sun for an hour).
2. Direct solar heating of water/glycol mix via vacuum or inert gas filled glass tubes with high efficiency collectors fitted internally (as seen in the video). These are very good but not the most efficient and typically lose most if not ALL their heat generation capability during hours of darkness. These units may, or may not involve the equivalent of a heat pump to improve the overall efficacy and efficiency of the system.
3. The very latest, and in my book as an engineer, the VERY BEST and MOST efficient technology (particularly for cold environments) is that embodied in the emerging cryo panels that operate night and day via heat pump technology. These provide tens of kW heat output per a few square metres in sunlight and an extremely useful amount during the hours of darkness even in temperatures down to -10 or even -20°C. Basically think of a big freezer panel capable of cooling to below a GOOD Sushi freezer (
@@boblewis5558 Today, in the real world, nothing heats more water for less cost than evacuated-tube solar thermal panels. I've been there, done the installations, calculated the costs. It's relatively straight-forward, reliable, doesn't require the hiring of expensive engineers and technicians and is able to perform far below zero if using a non-toxic glycol with heat exchanger. My home system has been running for almost ten years, without issues.
@@paulmaxwell8851 in terms of simplest installation and overall cost I totally agree. Anyone using solar PV as a PRIMARY source to heat a building or water is wasting up to 80% of their money AND energy.
The upcoming phase change technology I mentioned as number 3 in my list, without a doubt WILL provide the most total heat output though.
At present however it has not yet reached sufficient market penetration or prominence to be lower cost.
Installation wise it is typically a little less cost than solar tubes, due to simplicity of operation, but as it works 24x7 (albeit at a lesser output at night) it has a much faster return on investment due to winter night time energy savings.
Given the choice today, I'd probably opt for your system, but if there were a good offer on my favourite I'd plump for that. Air heat pumps are just too low in actual COP for the UK as well as horrendous system installation costs but nowhere near as ludicrous or disruptive as ground source pumps which are SO expensive, achieving payback takes far too long ... MANY years, even at today's energy prices!!
Hi , just to let you know that, you wouldn’t have to cope with the excess heat if you had a drain back system, they wouldn’t be any water in the panels, this would be because the water would drain back when the call for heat has gone
I've had solar thermal on my roof for many years with absolutely no problems. They are up to 70% more efficient than solar photo voltaic in terms of energy production. I currently have a 240v powered circulation pump but a solar powered one sounds a great option. My system has survived several hail storms and the worst thing that happened was two tubes became cracked. There were no water leaks. I just replaced the two tubes in about five minutes. I wash the glass tubes every couple of years. The only thing I have done to the system in recent year was mounting my tubes in air conditioning duct and conduit. They are good for appearance and thermal efficiency but the duct should be given extra support (to keep it closed) as the roof heat weakens it, and it can distort. The ducts and conduit should be painted. Prior to using the ducts my tube insulation was painted.
In regions of the United States or any other location wherein cold weather dominates for a few months of the year, solar thermal applications that work in conjunction with hot water systems make sense. Heat bills are the largest utility cost in regions of the country where winter weather is the norm for the percentage of the year.
Personally I like solar PV plus a heat pump water heater.
That can be a good combination but it does not protect you against power outage unless you have the right switch gear.
We don't get many outages, and the 50 gal tank holds the heat a long time.
@@tedrees5989 is exactly right (and he spells his last name correctly). I calculated a 50 gal tank would only lose about 2C over a 9hr period. I did a blog about a new hybrid heat pump + tankless setup over at my blog at tripzero.io
@@tripzero0 PV more ideal for urban as natural gas is commonly available. In rural / suburban where gas isn't readily available but comes with larger land lots solar thermal becomes more practical. Although, mainly more economically practical when building diy downspout thermal air and / or diy pex + aluminum hydronic sheets contoured to wrap around the pex.
Which either system must have thermal storage built cheaply to make it practical whether it be sheer mass of rocks or 250 - 300 gallon IBC totes protected by metal cages then spray foamed.
Take your drive way dig it up lower and grade it then plan out a solar themal pipe system pex will be fine. Use your drive way as the thermal panel pour concrete on them to protect encase and give thermal mass to them then cover the concrete slab with ashpalt ultra black. Its better if you put insulation under the concrete as the ground will leech the heat in the summer. If you dont want to use insulation you can use sand and gravel but go a few more inchs deep as the sand will add thermal mass. Black top gets very hot so this should work and since its ground level you dont need a very strong pump or maybe any pump to move the water.
Here in the year 2022 we slap a couple of second hand PV's on the bottom heater of our electric water heater, and hot water is free after that. Project cost
We have been installing drain back solar thermal systems for 8 years with next to NO maintenance. Minimum glycol degradation and great performance.
What is your company name?
@@VergePermaculture dh solar engineering ltd. Based in the UK. We love solar thermal and believe that each technology has its place. Thermal still has a massive part to play but I agree that systems failing due to bad design has given it a bad name.
But what about - 20 C temps in canadian winter(?)..
Industrial alu covers around your tubes , isolation is 3 times to small ! Once make a test with a thermal camera (in the winter ) ..;
I've had one for about 10 year and its always worked brilliantly
Like I think the best option is to cover your whole roof in solar 80/20 PV/ST and you can do it in steps if you want and honestly I would leave the solar thermal until last because solar PV has more functionality. Also I would be worried about the little solar panel getting covered, or something, I personally would want a battery backup, nothing to terrible large just something that can run that little pump for like at least 3 days and an alert that the panel is down.
out here in vietnam, solar thermal is still rocking. my house here has just 1 panel and covers the hot water needs for 8 people. will be installing another panel for a new house being built a well as prices for solar thermal here are very low. $150-300 for a good size panel.
I suggest wrapping a wire net around the pipes with a gap so their becks can't reach or you could put pvc pipe over the top. I realise its already plumbed you could cut the pvc pipe down one side and stretch over. Or there may you could use that pipe (has lots of tiny holes) they use for drainage and cut that to fit.
You can also get DC elements to convert at least 1, if not both of your elements in the water heater. Then connect the panel to the element. I love SWH, but I think it's so much easier to use PV.
If you build a big heat sink thats very insulated you can store all the extra there just as long as you size it right. Then you could crack open the insulation to let out the heat if needed.
If you put the solar thermal tube panels on the ground and connected the water pipe circuit to a hot water tank at a higher elevation, say in a second-floor bathroom, couldn’t you eliminate the need for an electric pump? Wouldn’t convection move the hot water from the tube panels on the ground level up to the hot water tank? Our wood-burner back boiler system has a convection driven, non-electric heat transfer to our hot water tank.
Great video I do have one bit bigger than yours but on multifamily house very happy with it, it makes about 70% off hot water. But i would not recommend it for one family residence.
In the late XIX-early XX centuries, engineers like Augustine Mouchot or Frank Shuman insisted that after the depletion of coal the civilization can rely on steam engines powered by Sun
Right now you can get a 150$ 10 tube+roof reservoir unpressurised water heater that can easily can be installed by yourself and have not all year but close showering pleasures. Compared to folovoltaic there is no comparison price and simplicity wize.
It will be interesting to compare cost and temperature functionality envelope of solar thermal vs. solar electric powered heat pump solutions.
Thank you for the video. Great solutions to thermal run away. They should all be built this way.
How to determine the size of thermal run away? And: Imagine the temp is so high that the "thermal valve" opens. In this case goes now energy at all in your water tank. Means it gets colder and colder. So I believe you need a slightly "intelligent" valve that opens the path through the thermal run away in case the water tank temp is as high as you wish.
Is the used valve "kind of digital"? Means have it only two states like "valve is fully(!) open" or "fully closed"? What about a "device" that shades the tube? Too complex?Too many things that can go wrong? Too high/too much additional maintenance? ... Would love to design the 100% perfect solution - that is "easy" = cheap, has low maintenance, needs no electric energy from the grid (like your DC pump = which is genius!!) ...
PV win every time...once the water is up to temperature the power can be used elsewhere. With a standard resistive element the components can all be insulated and under cover. a good portion of heat is lost in the transfer to ground level. I have tried both and I feel thermal is dead. Just purchased used 250w panels for 18 dollars a panel...why bother with water pipes everywhere. In my opinion it is equivalent to running a petrol car versus an electric car...less moving parts.
Thanks mister. Lots of interesting stuff here.
PV panels will never deliver hot water and space heating, another myth, but a quality heat pipe system will, as I have experianced over 16 yrs in my UK house. But you need a open vented Thermal Store, I first developed in 1991, now produced in litre volumes of 100,000 L
I would love to hear more about this, could you send me details?
Well, yes and no. I have a pressurized water tank system, a pair of tanks. Three 20-tube panels. More hot water than I can use. But yes, a really large non-pressurized tank would have been better still. I won't argue with that.
How long does it keep heat on cloudy days?
Could you design a sand heated earth bed from your solar thermal. Like a queen size earth bed. To be grounded when your sleeping like set-up in the basement to cut down on RF radiation.
Can be used to heat the home, and can be installed a big tank to store excess heating. When is cloudy you can use from that thank
The whole reason for me to mentally prefer photovoltaics to thermal is to avoid plumbing as much as possible. I don't like plumbing. I don't like heat exchanger loss. In most photovoltaic situation you don't know where to dump all this excess energy. My parents house have 1976 thermal panels, those work, but the main problem is the pump and sensors : a photovoltaic DC pump would be much better!
Run a DC pump ( around $100) directly from a PV panel. That's what I do. It's very reliable. Make sure the PV panel is at least double the pump wattage. Good luck!
Birds are an issue. On roof piping for ac same issue. What I have used with success is a pvc pipe covering. Too slippery for birds to peck apart. And they give up. Nice white clean look. You should look it up.
You can make a stand alone dc pv system that is way simpler and reliable that doesn't rely on grid power.
It's not dead.
But it is niche. The versatility/portability of electricity wins in many applications. Plus storage is bulky.
In the 70s I worked at a solar water heated and cooled factory. Yes cooled. Hot water accelerated evaporation in a kind of swamp cooler.
Anyway, within a decade of spending million$ to install the system, they dismantled it. All of it. An acre of panels that could be rotated to clear or avoid snow, as well as the sun once the 20,000 gals of expensive "food safe" antifreeze laced water had reached thermal max.
After the third unscheduled spill of 10,000 to 20,000 gals they realized they were fighting redundant extreme failure opportunities.
They removed the tanks and internal plumbing. Everything.
It's not dead. But it's still an unbroken wild horse. If you dare to ride the water collection method, don't get complacent.
On the other hand I personally know a guy who has a 20+ year old hot water system mounted on his roof. A pretty large system. All his families hot water, plus some heat comes from that setup.
A couple years ago he gave me a detailed tour. Very well engineered. He said it's paid off many times over.
would like a hybrid PVT panel but I do worry about the increased points of failure
Hows about painting the foil black.
Put wire mesh around it so they can not get close enough too get at it. A ring/tub design 4-6 inches.. is what i would try
very good ptoject #bestsolarpanelsystemthishashtag
Thanks for the idea!
Wow , Sounds good . I had never thought about this solution.. ... So you have revealed , once again, that "There is wisdom in a multitude of council. ( A quote from Solomon , King of israel )
For those of you who are doing Voltaic systems what you could do is just what Tesla is not the only company that makes power wall storage solutions there are other companies out there that make power wall storage solutions as a grid parallel system the grid parallel systems what they do is if your power walls are large enough and you have enough of them tied together your home actually runs off of the power wall and your solar and when the power walls get low on charge then they draw from the grid and when the grid goes down you don't have any disruptions because you're already running off the power walls and just charging the power walls off of the grid for your usage that your solar panels can't provide even though the Tesla power walls seem like a great solution Tesla has some for a limited them so if you lose connection to the Internet and the para walls lose connection to Tesla they are rendered ineffective and they go offline If they lose communication with Tesla for more than 24 hours But the Tesla Power walls being as smart as they are are really nice because the inverter they use can not only pull power from the grid but it is also a grid tie inverter and it can feed excess power to the grid meaning during the day if your power walls are full and you are solar panels are collecting more energy than you are using at the time it will feed that back to the grid Most likely at a higher electric rate then what you are using to charge the power walls at So there is Solutions for people who want to do photo Voltaic as well Because many people who are doing photo Voltaic who are primarily living off of great electricity are only playing these grid tie systems and as he mentioned in the video when a grid tie system is utilized if the grid goes down you don't have any electricity even though you have the solar panels Retie is good on a small scale for a self on installation considering there is a number of grid tie solar panels that pretty much come as plug and play panels at this point where the grid tight inverter is Built-in to the panel but for a larger installation you should definitely think about a battery backup solution so that way when the grid goes down you at least have the option to switch over to using your batteries and can at least power your home Essentials with your solar And if you're only using your Solar System for a backup power system and just occasion role utilizations to lower your electric bill you don't even need to have that many panels 500 W worth of panels would be good for an emergency utilization system just as long is you have 5 or 6 kW worth of batteries Andrew mystically it should be more between 8 kW of batteries to 12 kW of batteries or even more because you don't Want to run the batteries below 50% if they are lead acid or gel cell technology if they are a lithium battery Lake a lead acid drop in replacement 1 then 1 100 amp hour lithium let us had a replacement drop in battery Is good for a little bit over 1000 W of usable energy apiece Plus those batteries are designed to last many years longer 3 times longer easily and easily take 3 times the amount of cycles even if you are charging them fully and pretty much fully discharging them the lithium batteries are way better and a much better Bang for your buck to as a long term investment for how you are going to get your money back If you're going to invest the money in a Solar System and you want to make it a grid backup system the batteries are not something you want to cheap out on you also want to get a decent pure sine wave inverter that has a decently high rating for being a grid backup system as well your inverter should be a minimum of 2 kW and if your solar array is very large and your battery bank is very large you could easily find in averters large enough to power your whole home and despite what people say you can buy multiple in verders and parallel them together you just need to make sure that the output side is paralleled so they are in sync with each other so each inverter can act as a single phase side.
Cover the foil in something the birds hate. Or a hard shell like pvc.
paint the silver insulation tape to matte black color ..
Thanks for the advice.
To stop the bird from removing the insulation. You can cap it with silver metal. It takes a little work to look good but Will stop them. Like your video very helpful Thanks
Thanks!
PV panels deteriorate over time in direct sunlight, they eventually fail. Naturally, some are better than others.
do you have to use ethyl glycol, why not alcohol or propyl glycol? you can buy five gallons of propyl glycol for END's systems aka e-cigs fairly cheap.
it would be beneficial to upgrade the tech to make as hot steam as possible
thermo couple to make electricity from hot water and steam
you could have passive copper heat regulation system, like house heat radiators
fridges run with heat too
I use PV without battery and converter. The AC current is dangerous. Don't get above 200 Volt. Use a AC Switch.
It works fine.
I use DC not AC
Hello, i do have 120 58mm 1.8m vac tube, 4 manifold, Grid went down i was panicking, emptied the system so no pressure, than i was out and the system went mad, overheating, manage to bring it under control, i like your dc system, can i purchase it please, or let me know what his needed, Thermals r a lot better, got rid of gas in the house, thank gordy
Mine works perfectly...9 years now and 1 change of Glycol. and VERY hot water all year long. from end october to mid march it just raise the water to 20/45 degrees and the bio mass boiler complete the rest.....
Hi interesting video and insights, I was interested in the 3 way value you mentioned to divert excess heat to a dump load. Do you have a link or further information on the value you are using?
I am interested also in this 3 way dissipation valve..Need a link.
@@grokstone Just google mixing valve. They are common to all hydronic heating systems and easily adjustable.
Technical but easy to understand as always. How is the bird problem going? I've had luck with ultrasound to deter them, though I only found one model that does the job. Good luck!
I was on a small farm in sweden and they used a thermoelectric generator to generate electricity from the difference of the house heat and the outside. Maybe yu could use a thermoelectric generator to get energy from the waste heat from the solar thermal panel. If you put up another panel you would get more hot water and the possibility to get more electricity. I do not really know if this might even work. Thank you for the nice video.
why there is no converter for heat energy (ionize the metal by heat to generate current) to electrical to avoid wastage when overheated occurs?
Hey there, hope you are well? I loved all your eco friendly things. I think it's disgusting that every new build by law doesn't have at the very least PV panels on the roof to feed into the grid, at what point will the world wake up to the issues we've created?!
But anyway, I'm looking into solar heating for my dad's very very cold house. He lives in Portugal which sounds great for solar heating options but actually the houses out there are (or were) built so badly it's actually quite difficult. So there's zero insulation and the walls are just one piece of very cold concrete right now. I have been trying to work out if solar heating could heat the house or if he needs a proper gas central heating system. There's nothing in the house at the moment and the winters are getting too much for him and he's actually getting quite ill from the cold so I need to step in and do something.
I'm not really sure what to do about the insulation yet, tbh the whole house needs knocking down and a lovely warm modern home build but sadly that's not an option. As a quick fix I kitted out the lounge with thick insulation form boards, it looks odd but works an absolute treat and with either an electric radiator or the log fire the room gets lovely and warm and stays warm. I guess maybe cladding all around the house to create a second insulating layer is possibly the best way to go, I'll have to look into that a bit more.
Looking at my solar options evacuated tubes seem very impressive, especially on cold winter days which is when he needs them most. I just wondered if you thought heating an entire house with thermal panels is doable? Or am I missing something obvious like of course can't heat a volume as large as a house because of X, Y, Z. I guess any calculations would be hard to do without know the exact about of heat getting to the tubes, efficiency of the system, size of the house and then how well we can insulate it. But do you have any pointers? Any idea on how many tubes would be needed for a house sized project etc?
Can you split a pvc tube down the length of the tube then open the tube put it over the aluminum pipes to protect them ?
up i used splt "french dain" split so i could get more insulation
Solar Thermal IS DEAD for residential hot water now but this is an old video. Maybe it isn't dead for solar plant growth assist etc. BTW it does use electricity just not grid electricity. This electric component can fail also causing the same problem as a grid is down. You dont need a battery bank at all to heat water with PV direct power and basically nothing to leak etc.
These systems are very popular in Mexico.Propane gas is expensive and most people use these systems to heat the water in theirs homes.
what are the advantage of that type of solar thermal panel as opposed to the copper pipe 4 ft by 8 ft solar panel with glazing on the front?
using plastic cable ties to create some sparky to prevent birds.
Why do so many americans take into account grid failure? Is it that common? I personnaly have never seen a grid failure in my life. Is it different in the USA?
We had a 50 million person failure a couple of years ago for 2-3 weeks in eastern Canada and the US. Read the Black Swan by Nassim Taleb.
Hello Sr. I am trying to install a system like yours for our pool can you please advise me about /like where to buy the tubes and the 3-way valve etc, thank you in advance, respectfully Dio
Simple Solar! Calgary Alberta eh
the 3way helps cool if over heating
Good ideas. Thanks!
I wish such experts looked at thermal stores, which can dump all these Glycol myths and the use of pump stations and closed loop systems. My new heat pipe tube collectors shut down at 80c, so you can over design for greater winter hot water for heating, without the worry of over heating in summer time
Eric, I would love to see more details on your system sometime!
this is my personal and business combined web site (www.thermaltricity-int.com) includes my e-mail contact
Hi Rob again, I have re run your video twice and love how you are explaining all your problems and most of the worlds problems regarding solar thermal and why the solar thermal guys jumped ship to install PV systems, as there is 90% less call backs.
I did not start in developing a solar collector until after I started to sell my own hot water tank design.
The KEY to solving every solar water heating issue is to re educate plumbing, heating and solar thermal engineers to how a THERMAL STORE WORKS.
I was one of the early pioneers of Thermal Stores back in 1989, when I owned a luxery batheroom showroom/installation business.
Unlike the USA and most of Europe, you have all been sold a unvented pressure hot water cylinder, heated by gas or electric. In simple terms, your cold water at mains city pressure flows into the bottom of the tank and flows out of the top.
Then the solar era happened and for the USA was all about making BIG boxed flat plates with copper absorber tubes under the glass. BUT, then the tank companies added a solar coil, that was the start of all the failures we have across the world today
Hi Rob again, to how maybe YOU and 20 others LIKE YOU, could re start solar thermal as I have been developing successfully until the banking crash.
Every UK solar system I sold when I owned my solar distribution company up until 2009, was always with my open vented multi fuel hot water tank, made in copper in the UK, today is made from stainless steel, but again NONE pressure.
My larger longer coils in my thermal store is not for solar, its where cold water at mains pressure passes through the bottom coil, then into the top coil and flow out to your showers and baths ect at MAINS CITY PRESSURE.
In order words, the delivery of hot water is INDIRECT instead of DIRECT as common across the USA
The water in the vented store is now none drinking water, which is the same water as in my Apricus heat pipe collector I developed with an Australian in China back in 2001.
I have NO solar coil, no glycol, no pump station, no closed loop parts, becouse all my fill and vent of the collector is through my open vented cylinder.
I have proven all this in my UK home since 2001, plus the solar heated thermal store also supports my home heating through 12 steel radiators. My system costs, is $500.00 less than your system, and zero service costs.
Great video
No just hook your PV directly to a DC water heater, then you need no battery and you need no grid, and it's cheaper. It's just about how you choose to use PV.
Yes it is a good idea, but only if you have enough space for a large Solar PV array, and you can spare the power that will not be going into your battery bank, people must remember that some of the best PVs are only 22% efficient at converting light to electricity, but even homemade solar thermal can be around 70% efficient at converting light to hot water.
It really does depend on circumstances, using electricity to heat water is simple and convenient.
BAD IDEA. Electrolysis
search for bird spikes on amazon. They are spikes you can wrp around the section the birds are pecking.
Solar thermal-up to 80% efficient at converting sun to heat. Can be stored in sand or water for later use.
PV-20% efficient, requires chemical batteries to store electricity.
They both have advantages, but roughly 70 to 80 percent of total residential energy consumed is as raw heat. Only 20% needs to be in the form of flowing electrons.
If you install an AC system based on evaporative ammonia chilling (like propane fridge) you could also meet you summer AC needs with thermal.
Batteries need replaced. Sand doesnt. A 10x10x10 foot box heated to 800f and cooled to 200f equals the same amount of natural gas as 2 months of what I use during winter in our 1400 sq ft house.
Just some thoughts off the top of my head.
That's why I have grid-tied PV. I can also export surplus energy when I'm away. Can't do that with thermal.
Wrap it in metal mesh screed to prevent the birds from pecking...
PV water heating is in its infancy and just about no one on youube is doing it right. I heat water with PV and it is pretty nice. It works in conjunction with the off grid system and any extra PV energy goes into heating water. It is dirt cheap to build. All that extra energy from a few additional panels allows you to run a smaller battery in your system and possibly some AC in the summer. I have only one battery and have a dishwasher with heated dry! The heated dry is part of the PV hot water electronics. So you are right. The PV systems out there mostly suck if using batteries and inverters. Done right it is pretty sweet. And relying on anything solar to provide 100% of hot water is not economical.
Thanks for your comments.
If I wanted to supplement the heating of a greenhouse could it be done? Heat Black barrels and extra heat into climate battery?
James Coleman You could certainly use it as a heat source for a greenhouse. I was actually thinking that the heat reject line would do well plumbed into a ground heat sink within the confines of a passive solar greenhouse.
I have system u can make ur self look me up or go to Guilt Free Hot Water
Install a 1/4 " screen around all piping. stand it off far enough so the little guys can not reach it. How about a battery operated blind which rolls down and reflects the sun?
Did anyone ever get a response from the question on the link for the 3 way dissipation valve. Since it is so important, I would think k it would be available.
Isn't it just a 3 mixing valve like the ones used for an outdoor wood boiler? Used too cool down domestic hot water so it doesn't scald? I'm just getting into this vacuum tube for domestic hot water and possibly floor heat and will have to address the overheat issue at some point also..
Can't you install a drainback to a storage tank instead of a dissipation devise?
This is an option, yes.
No! The evacuated tubes must be cooled if they are in direct sun. If you were to drain the system the heat pipes would overheat and the foam insulation in the aluminum header would be damaged. I've seen it happen.
As long as the sun shines you must keep that pump running to remove the collected heat. If you no longer need the heat then dump it. There are numerous ways; mine is a liquid-to-air heat exchanger with fan, very much like a vehicle radiator.
I would use
en.m.wikipedia.org/wiki/Thermal_mass
Solar Thermal is not dead, the future for thermal is with PV as a PVT system with a thermal store and a water to water heat pump, which powers the heat pump and turns waste heat from PV panels up to 60-70c to heat water
I agree, however, a lot of professionals around me claim that they are.
If you spend money heating your home and use more than most in heating water then Solar thermal is obvious. Think everytime you wanted to boil your kettle, the water was already warm. Poor solar thermal installs are no different to poor pool PV installs. You can install underfloor heating and dump the heat into your water tank. I'd like to see options to allow hot water to be used in clothes washers and dishwashers. Your heating water to do this daily. Free heat could also be used for Tumble dryers. In theory free heat can also be used for a greenhouse to accelerate crop growing even if its just for home comsumption. Naturally in Sun Belt areas, PV to power Aircon (or offset the grid cost) is a better bet as Aircon sucks power when the sun is out and so its Solar PV working (PV storage then allows that excess power to be used later or to recharge something regularly). If you do used energy to heat your home interior then thats the biggest power of your home energy bill, way more than cooking or your electricity bill (for most). I notice alot of solar thermal owners start out with one panel and then add others later to boost the water heat presuming they can find uses for that heat.
Thanks
Cool system. One way to stop the bird problem is go to your hardware store and get some HVAC foil tape.
That is what I used. The birds love it!
The birds are probably attracted by the shiny reflection. Can try to spray paint it. Alternatively, if the diameter is suitable, cut pvc tube/pipe in half and wrap over the pipe insulation to give it a tougher shell.
You might want to use fiberglass pipe insulation instead of armaflex. It's totally worth the cost to have insulators installed it and clad it with aluminum. Magpies will be a thing of the past.
I want to learn more
Great idea having a PV-powered DC pump! what voltage is it? Where can I get some? I'll be heating a 350m3 underground STES, so I will never have too much heat! (capacity from 25-55° is ~25 MW/h)
The PV-direct pumps I use are available in both 12V and 24V, and three sizes. I buy them from U.S. Solar Pumps in Pennsylvania.
Have you looked at pv direct to heater element and compared?
what’s the website for your friends company? I’m interested in a system like yours
What type of DC motor are you using? Any recommendation?
Cold Steam the efficient way to use the sun or composting and rocket stoves as heat sources to produce electricity and or distilled water explained from basic concept to employment. Water boils in a vacuum at 75 F or 24 C
Two open containers one full of water the other empty connect them at the bottom and water will reach an equilibrium 50 50. If one is sealed except for the connection the other will remain empty because of the vacuum created in the sealed container.
Gravity will overcome this vacuum if the containers are taller than 34 feet.
If the tanks are 40 feet tall the tanks will reach an equilibrium of water levels at 34 feet leaving six feet of hard vacuum in the sealed tank. This makes a vacuum pump set we need two of them if we were going to distill water as the cold side open tank is used to collect the distilled water from it as the continuous input of water needs to go somewhere.
Each sealed tank has four valves three at the top two of those on opposite sides (B&C) one at the very top (D) one at the bottom on the side (A), water-based vacuum pump operations are, Close bottom tank valve A and top tank valve C. Open top tank valve D. Fill sealed tank through top side valve B. Close valve B and D when full. Open bottom valve A.
This primes the system to let the warm water in that will vaporize and run through the system when you partially reopen valve B (to control flow rate) and open valve C to its fullest.
For only power generation need one pump set and one vacuum tank so we can have a Hot side and a Cold side one to boil the water and one to have the low pressure/vacuum to draw the steam in through the turbine then the cooling coils then to the tank.
At the bottom of the cold side, tank is a return pipe with the one way valve to the heat source the one-way valve prevents expansion back to the cold side and as the hot side vacuum chamber is the only outlet for the expanding water and it is drawn by the vacuum the cycle proceeds.
You can combine the two and get power generation and distilled water keeping the return line from the power generation system will let you switch if you don't need distilled water on a continuous basis in large quantities.
I am going to make one feel free to make one as well it is open source.
Tried to wrap the pipes around with wire mesh
Snakes will discourage the magpies that are causing your problem. This even works in Hawaii where there are no snakes, except rubber ones..
I like Brad Lancasters hot water tank system. Now he is not in cold Canada so his might not work well where you are at either lol.
Sounds like an over complicated solution to an existing simple function?
one time where to much Cha Cha Cha is warranted. aka too much explanation LOL. Bona fide Certified Photovoltaic / Solar Technician here. Solar Thermal is not dead. reason they fail is because of those who connect it wrong. the flow at the Flat Panel Collector is wrong. your solar thermal collector is a Evacuated Tube Collector. the three way valve is called a Mixing Valve. giving thumbs up on your video. i Like, OLE!
by the way, crows, magpies, ravens like shinny things. they'll steal jewelry. that's why they're picking at it. take that off and leave the black insulator.
Is there anyone in Texas that sales and installs these systems? PLEASE let me know
Can magpies chew through aluminium sheeting? It seems your actual problem is that you're using the cheapest solution in exterior conditions and then you get exactly what you asked for.