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Building a Solar Hot Water Competition, Thermal vs. PV
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- Опубліковано 1 лют 2019
- Which is best to heat water, solar thermal or solar PV? I'm building a real life test to compare the two. This is going to be a long-term test so we get sunny days, cloudy days, cold and hot. Lots of data will be gathered and shared to dive into the efficiencies of each system.
I have flat plate solar collectors to heat water on my house and garage. The garage system is connected to my radiant floor and heats the space. The house system is tied to a 250 gallon thermal storage tank for heating domestic water (DHW).
I'm using two salvaged 55 gallon drums as my tanks. By using the barrels the two tanks are equal volumes. The Thermal tank has a temperature differential controller and a 12 volt DC pump. The PV tank has a 48 volt DC 1500 watt element.
I'm using an Onset data logger to capture the tank temperatures in detail.
If you would like to find out more about why we are building this experiment, please watch our introduction video here: • Solar PV vs. Solar The...
Playlist building my solar hot water system in my house: • DIY Solar Thermal, DHW
Bandsaw: www.harborfreight.com/10-amp-...
Bandsaw Blades: amzn.to/2GhFjMQ
Pump: amzn.to/2Wh9BF6
48v Heating Element: amzn.to/2Tehx83
“As an Amazon Associate I earn from qualifying purchases.”
Thanks for doing the leg work! I'm looking forward to the results!
The shot of your baby started out my day on a very high note, Thank you for that. Now I will watch the rest of your program.
Good job. Great video. I look forward to the test results. I have a drain back preheater system using that same small pump you are using ( replaced the pump about 4 times) and its been working for about 4 years. My summer temps hold at 120 degrees most of the time. Winter temps with a week of clouds has never gotten lower than 65 degrees. I have a heat exchanger made with a 8 gallon stainless tank in a 2 hundred gallon hot tank with 2 inches of ridged foam all around. It started out as an experiment, but it works so well I am still using it.
Looking forward to this experiment, solar panel option appears to be a simpler system to install in comparison. Keep up the good work! 👍
David! you're the man! Just really enjoy all your stuff. I doubt there's anything you couldn't accomplish once you decided to do it. Love your wife and daughter occasionally getting in on the action. (I'm sure they're much more involved than we actually see in the finished video.) You have such a great attitude about work. Good luck in all your endeavors.
Thank you very much.
I don't know why I am like him😂😂
It will be interesting to see the results. Based on my own experiments and back of the envelope calculations, I went for PV heating of my standard, two element water tank. In the end, the simplicity of no moving parts, no potential leaks, and relatively low voltage sold me. Long-term, I'll take reliability over a little efficiency. Thanks for sharing your experiment!
It won't be long, I'm editing a "results" video now. Thanks for watching.
This is an excellent video...been looking for something like this. Thanks so much for all the effort.
Your welcome. I wanted to figure out where the limits were. It was a fun experiment to set up and build.
Very ingenious and simple on how to mill the 2 x 6s flat. 👍👍👍👍
Man that was cool makes me like jigs even more.
KUDOS for your effort. I see you know how to wrap the lines. I bought tubes for $10 each from China. Shipping those things is high unless they are containerized which would be thousands of tubes per container. The 80 tubes I put in 1 got broken when the class 3 hurricane hit that complex in Victoria texas 1.5 years ago. Didn't bother the array. That was pretty phenominal since it caved in the side of 1 building and ripped 2 HVACs off the roof of one building and tossed them into the courtyard 60 feet. The hail and wind didn't break the tube but a piece of shrapnel hit the end tube. I did wipe the tubes off last year as they accumulated pollen and dirt over 7 years.
GOTTA see what your finding are.
Love your projects, keep em coming.
I Installed a Grumman/Sunstream 80gal system in 1978. It was perfect for my cape code south facing roof at some three degrees off optime wintertime angle. It lasted thirty years.
The year befor the install my old oil fired boiler with domestic hot water used 200 gallon of heating oil from mid March untill mid September. I was told by the hvac guy the boiler was about 60% effeciency. The first year of the solar unit the fill up was 20gallons, a shock to me and the delivery guy. My observation was the 80 gallons of 150 to 170 degree water was dumping heat into the boiler, tempering the heat which served to prevent the boiler from needing to run. I almost never saw the tank tempture below 100° even on shortest day of the year.
As a stop gap, when the tank developed a leak I put a 50 gal electric in place of the 80 gal tank. My electric use went up 280 Kwhr month over month in the fall thru spring period and 200kwhr spring and summer..
I'm now installing a PV powered electric hybrid 50 gallon unit to be run on hybrid mode only. Will comment aftet a year of use.
I am skeptical of home made systems and the cost of a hybrid electric with PV is likly close to what is spent on a amature efforts!
Dude @ 4:00 I was salivating thinking how elaborately you planed that deck! 🤩 THEN HE PULLS OUT A PORTABLE BAND SAW! 🤪🤪🤪
You had all my toys in your video. Router crimper stapler and plumbing. Only I like to play with pex. Good video glad I found your channel thanks
I love working with PEX too. I can't use it with a drain-back system because there can be conditions where the panel gets hot, then the pump turns on, and the first little bit of water steams and that steam melts the PEX. You can probably use PEX with a closed-loop glycol system, but I've never built one of those.
Watching with great interest.
Thanks for watching.
dude , that router idea was just plain genius.
Meh, just bust out the grinder with a flapdisk and eyeball it
Cool setup with great effort and simple explanation.. really curious how they would compare..
I would use both. Solar thermal hot water heating to get the water up to temperature and then feed that into a hot water tank to hold the temperature. When the temp drops then I'd have the tank draw electricity from a battery bank powered by photovoltaic panels to keep the water at temperature. That way instead of trying to heat up over a large difference it can sip on electricity to just maintain.
How about a water jacket on the back of the solar panels. Use the heat the panels absorb to warm the water and then the power from the PV to heat it further or on demand.
@@Sethjxl that's a good idea for fresh/cold water to pass once, if it recirculates, it's going to overheat the panels
@@Sethjxl Another problem here, Seth, is you run into serious heating differences on the panels and it causes them to literally shatter, Wish I had that on video from my experiment... $200 solar panel wiped TF out half way through the first day lolol
Outstanding idea. I was going to respond with combining the two myself. You took it a step further. Good job!
@@Sethjxl a hybrid as you described does exist for the purpose of cooling the pv temp to optimize its output but it can do as you say
I like this test very much! Thank you for this video David!
Very nice experiment. I am installing solar water evacuated tubes system. Evaculated tubes are so efficient then thermal according to me. I did experiment on both of them and Chinese evacuated tubes win in the end. It is more helpful in North then South Florida.
But we have lot of cloudy days so its same.
Id love to see ur system?
Nine work when cloudy,alot less but still
Solar electric heating usually uses the PV to power a heat pump. You get about 4 times the heat energy from the same PV power that way.
This is super cool got me interested in solar again
Wow---what you folks with brains will do to prove a point! Got to say I love it because I would have NO idea how to do any of this. It's a hoot to watch y'all. Thanks
Thanks for watching. If you have any questions I'm happy to help.
Great experiment. Very interested in the outcome. I subscribed!
Thanks for watching.
A fair comparison would have equal surface area for collection. The photovoltaic has a distinct advantage in this test.
Love the project and the progress.
Thanks for watching.
Very cool experiment !
thank you for solar thermal video
Awesome comparison David!
Thanks.
This was great I'm Also from mass and looking into solar thanks for the video
Looking forward to seeing the results, because I am looking to do the same!
Hopefully I save you from having to go through the hassle of setting up your own experiment.
DavidPoz Hi David yep that might be, currently I have start looking into underground heat source pump system and place temperature gauges around the garden to see the range. We have here in the UK, Wales to be precise, and above ground it’s 4.5 c and a meter down or just over 3 feet, it’s 6.8c. But this is near the house going to plant some further out!
For comparison sake, why are the 2 sol.arrays not of the same size?
great work!
You have definitely satisfied me in elaborate planing methods, not taking a shot at you, likely what I would have done in terms of thought process.
Thanks Blaine Reeve. My goal is to give both systems the best fighting chance. I don't want to favor one or the other.
Sweet Job! we have to do a SHW project one time!
God bless the work of your hands
Who said the work of science was easy?! LOL.
Thanks for your followup.
Great video!
Awesome show thanks
I have been wanting to do a side by side test like this as well David. Cool deal. I think doing both as a hybrid system is the way to go in the end for anyone looking at solar thermal or electric hot water and get off NG and propane. Both systems need the sun to work however at least on the electric side you can put a cutover switch to battery storage and run that at night. A separate battery bank from your solar battery backup or off grid setup, since voltage to run the DC heater element is much higher than 24v or 48v solar battery setup.
Dave you got quite the setup 48 volts at 1500 watts is'nt that over 30 amps 😀 definitely interested in seeing the outcome of this project, May the force be with you 🤔
The next video I make will be about the electric side. But, yes, the amps could be over 30 given the right conditions.
Amps mean little - 48V @ 30Amps = 1.44kW. The heating element is 1.5kW. But 2 panels can only deliver about 560W depending on their rating. Meaning to fully energise the heating element he’d need 5- 6 panels in parallel (assuming each panel is around 46V. Alternatively David could just use a diverter and use his full system. There in lies a bit of the problem - for solar panels to be effective you generally need more sq metres of roof space. But cost wise they’re pretty comparable.
The solar thermal panel works best at low temperatures, then efficiency tapers off to zero. After this comparison test is done, try mounting the heating element halfway up the tank that is connected to the solar thermal panel. That might work best, with the solar thermal panel heating the cold water first, then the solar PV raising the temperature of the top half to bath water temperature.
Evaculated solar tubes works best compare to thermal. Both has it's own advantages and disadvantages. Evaculated tubes are light and could heat up to 212 F
This will be a good test and well done
Thanks.
The most efficient solar hot water system is a non-draindown glycol thermal syphon arrangement. But, the tank must be above the collector. Thermal syphon systems are both self pumping and self regulating. There is no need for ANY pumps or control circuits. Glycol will flow everytime the collector is warmer than the tank and will stop as soon as the collector is equal or coller than the tank temperature. Give it a try. I think you will be very surprised at how efficient they are.
You shouldn't bath or drink Glycol
@@homertalk You shouldn't drink radiator water either.
Water destroys glycol any day in thermal dynamics..sorry friend..
On the solar therm o heater I would have placed the return to tank line at the bottom of the tank. Your dumping all the hot water at the top . Won't be heating as well I think. Dang, Painting the inside of those drums with a good coat of Epoxy Paint would have been enough to make them last a fair long time.
This is very interesting to me,,, thanks for the entertainment,, Kinda like Bill Nye the science guy
thanx 5 sharing myan
great content thanks
Went to the beach put 3 quanity x 1 gallon black glass jugs in direct sun light temp was 112 degrees very hot. To hot to shower with had to use some 1 gallon glass clear jugs at 90 or 95 degrees just right. Temp out side 2 weeks ago in August was in high 80's or low 90's in the sun.
You need a buddy to help you, sure make things a lot easier! Maybe your friends are like mine. When they want help I’m always around to help them. But when I need help my friends are no where to be found! LOL
I am already running my home geyser on PV solar only - no grid input during summer halve of the year. We have a 150 litre double insulated standard cylinder with 6 x 200W panels and custom controller to serve 3 people and there is always hot water. The controller is set to 72 degrees Celsius - it's high to limit hot water use and keep some thermal mass for mornings and cooler days. During winter we will use some gridpower to top up the temperature. Location: Cape Town, sunny South Africa
Interesting watch. I do not know how often you work with your solar panels, the first time I soldered and crimped with pliers the MC4 connectors easy to do. Now I have an inexpensive crimper. But just buying ends and having cable may be handy for you, instead of a full roll you could buy a 100' jumper and cut it to lengths perhaps.
Thanks. I'll probably try that if I build another array. I just don't do this very often. Thanks for watching.
Interesting concept to using PV panels for a heating element. Basically you have a system that doesn't have a freezing issue except for the water in the barrel. Now if you can only move the whole deal closer to the garage then you could keep the barrels inside and avoid long cable runs (death to a DC system) and any heat loss would be inside. I'm curious to see the cost difference between the two systems and which one heats more water quicker. BTW, I still feel cheap electric water heaters ($100?) would be a better choice for your tanks. They come with many threaded fittings, t-stats, insulation, heating elements, (that you don't have to use) and are generally lined for corrosion issues.
Yes, I have an electric water heater, 50 gals, as a tank for the solar water panel. The pressure relief and drain ports are perfect for connecting to the panel.
Running wires is much easier than running pipe lines that far, and more efficient as well. It's also much easier to relocate the barrels, if necessary. You'll lose too much heat through pipes, unless you can insulate them with aerogel. DC really isn't a problem for wires, just the terminals. That can be largely solved with dielectric grease.
King of the solar panels bro
I'm interested to see the results of this, I bought a load diverter to try this, in the summer my battery bank is charged by noon, so I can divert 100 amps at 24 volts straight from my solar panels, not my battery bank to a element in my outdoor wood boiler
One thing I might add is, the bottom of the 55 gallon drum conducts to the wood meaning you will lose reserve potential of temperature by the loss of the seam at the bottom of the 55 gallon drum. Test this theory of mine in the cold of winter and see how warm the wood is at base of drum.
What I did I just used my 50 gallon water heater and changed out the two heating elements and replaced them with two 12 volt elements I have one 245 watt solar panel running it works great
You've convinced me. I own a place in Colorado and Minnesota. I've been looking at water based panels but now that I've seen your test is seems the PVs are going to be the most cost effective to heat water. PVs aren't my favorite choice due to the natural resources needed to manufacturer them. Any thoughts on that topic? My goal is to build an off grid water heating and storage system for water and space heating. Maybe even incorporate a heat pump in the mix. Want to find an inexpensive and easy to diy way to transition into off grid solar.
Thanks for sharing your experience. The videos are great!
The Colorado place 100% gets the sun necessary to feed a thermal water heater system year round if it's built right.
Minnesota might be more dark and cloudy in winter?
Here in the PNW I've just accepted that I need to use wood for winter heat because we're just too dark and cloudy for a modest solar system to provide it.
Got to save my batteries and drastically reduced PV production for the refrigerator and freezer and miscellaneous power uses (technically I could shut the fridge down and use the outdoors with some kind of well protected locking cabinet... But getting a fridge sufficiently clean and empty to sit idle for months without anything nasty growing isn't easy lol)
making those boards flat was genius.
You could listen the low boards, and shim them!
Impatient to know the results.... Btw, don't forget to add the extra mount of power in favor of the solar panel linked with the 12V pump associated with the thermal panel. It won't represents a lot of watts .... but can increase a bit more the temperature for the pure solar test.
I'm sorry, but I don't follow...
@@DavidPozEnergy Your thermal panel need a 12V pump turned on ? right ... so some extra power to be added for the solar panel to be fair....
O, OK. Thanks for the clarification. I have a kilo-watt meter on the extension cord that runs the differential controller and pump. I'll let everyone know how many kwh were consumed during the test. Thanks for watching.
Great work, if it's possible to make the chassi of solar panels rotational (motorized) so it's perpendicular to sun all day the effeciency will be much mich better like more than 50% 👍
heya that is gone be a nice test
That poor pump. All those metal shavings...
I just got 2 of those panels. Wait for it... FREE!! This video is awesome!! Just genius!!!
thats a good experience...think the thermal is more efficient..
Turn water on and off with temp in the collector
Next trip use the top bungs and an inside pipe to drop the element or find an old water heater to salvage.
love the router trick
Thanks. I use it once in a while for making table tops from wide glue-ups.
I live in a rental unit in Australia and we are fortunate enough to have a solar hot water service with a gas booster. It works amazingly well in summer but even in our winter's without the booster the water only gets warm. I know because we had a problem with the gas in winter. I suspect the PV will do better in winter.
And our winter's aren't even remotely cold.
That's cool you can use renewable energy even in a rental situation.
I live in Massachusetts state, US. So we get pretty cold. I have a big 250 gallon thermal tank inside my house and this time of year it can't seem to get very hot. That's one of the reasons I am doing this. My wife does not like "warm" showers, she wants them "hot".
@@DavidPozEnergy ah I completely understand. I'm watching with interest. Having said all of that with a gas booster I have the cheapest electricity bill ever. Looking at it perhaps you could combine them into the one tank. So that you can turn on the water heater when needed and the thermo panel takes the edge off the water temperature and the element finishes it off. Maybe after this you could add the element to the thermal tank and try it out.
When I say gas I mean propane we call propane gas and gas petrol.
This is going to be a fun experiment!
Thanks.
Also going to be very expensive - thank you David! I hope you get value out of the resulting systems.
With the drop of PV prices direct solar hw just makes less and less sense. Once you add the piping, the maintenance of the panels and hardware like relief valves. Powering the pumps, the controller cost. Replacing all those items during life cycle. A PV system, one you will likely use to power other stuff and spread the cost over more quality of life items starts making more sense
you need roughly 7KW to heat 120L of water to 80C over a period of 4h 30m
can you afford to install a 8-9KW PV system? oh, wait, it needs to be over 10KW because nothing works at 100% efficiency ...
Looks like a very nice set up for a test. I like the attention to detail. I may have missed this, but, to be fair, I would think that the solar electric should have a MPPT and be of the same collector area as the solar thermal...
I would love to add an MPPT, but I'm not very good with building electronics. I've watched some of Opera's videos because he makes some, but I don't understand how to do it yet.
Using the same collector area is not fair due to the efficiency differences between thermal and PV. You need at least double the area on your PV to make it closer to and apples-to-apples comparison. If PV ever gets to 40% efficient you can get the job done with similar areas.
@@TrackGeeks isn't that the whole point of the test ? IE: to see how efficient PV is vs a flat plate collector per-sq meter of exposed area ? .....lol
If its sunny then solar heated will win, if its cloudy then the PV will. Best option is build both and use them both at your home. I used to make solar boilers and panels. Every house should have one. (i would not put solar heating after 55-57 latitude, ambient light would be better for installing a PV )
A good video. However in my system here in Europe we use a much smaller diameter of copper pipe on a thermal system..12mm to be precise. This saves thermal loss on the copper pipe and moves the water around the system faster, but not the same quantity obviously cos the pipe is smaller. To avoid using a pump I use thermo-syphon but as you say for outside this causes the problems. My system is also an indirect one so I can use anti-freeze to prevent problems in the winter. Heating water from a woodburner via a back-boiler we use 3/4 pipe which heats the water quicker than the solar, and again this is an indirect closed loop because it shares the same tank as the solar feed ( twin coils) Good vid though, thanks
One StarTraveller Markeymark , interesting about a smaller pipe being more efficient. It makes sense but it's not intuitive at first!
Has anyone experimented with compressed R410A panel? It would be a thermodynamic solar flat panel, sort of an an air source heat pump.
My vote is for the solar water heater.
You mentioned adding another PV panel to the electric heating tank. I'd like to see the experiment with equal sun collection area, (like a single 2x4 foot panel on each for example), or an equal build cost (say $200 worth of materials in each case, which might amount to 1 PV panel vs multiple thermal panels). I'm just looking for some sort of "like for like" comparison, either with space or cost (or some other item... build time?) remaining constant between the two. Thanks for the great work.
I was thinking the same thing when I was first planning this experiment. It would be very cool to have equal area of both. But, I'm working with panels I already have and won't be buying new panels just to get a unit size that matches the area of the collector.
Once the experiment is over I will gather the data, and normalize it. So we can see BTU's/sq.ft. I can also show the data in BTU's/$.
Thanks for watching.
@@DavidPozEnergy Excellent plan! Keep up the good vids. I've subscribed and will be watching for updates.
To make the test fair the solar thermal panel should have the same area as the PV panel. The amount of energy received from the sun varies with latitude. The average is 1000 watts per square meter, you are probably less up north. The PV is starting with an advantage receiving more energy right from the start.
I had the same thought at first, but that only applies if its on valuable limited roof space, But as its ground mounted if its cheaper to have water panels vs PV panels that would win, but they aren't cheap i don't think, so its likely better to just to buy an extra 5 PV panels to help heat water.
Very intrigued by the idea of using the PV to heat water.
I have 1200W of panels standing by that I was considering for a battery backup system, but now I am thinking 'thermal battery'. We all need and use hot water, so instead of dropping a huge chunk of change on electric batteries, an open vented heat exchanger to preheat my water heater inlet side would be a great way to utilize that energy simply and cheaply without having to plumb pipes all over the property to a liquid solar collector. Just waiting to see how well it performs!
That would be a great way to start using them right away. And if you don't like it, you can always add batteries later. I did something very similar last year. I wanted to get using some panels I had so I hooked them up to a heater: ua-cam.com/video/jFoxIit8NYA/v-deo.html
Further enhancement might be to use a portable air conditioner to improve efficiency. I.e., exhaust the cool side and save the hot in the winter, and dual purpose it for cooling my garage during the summer heat.
You may want to take a look at the TechLuck MPPT converter for this purpose.
To my knowledge there is no video out there where a proper comparison has been made to prove that device (Techluck) is MPPT and makes more hot water.
I have found a study of MPPT vs. Non for DC solar electric heating which supports the claim of improved efficiency. I couldn't find reference to what MPPT they used however. It appears legitimate and well thought out with controls.
"Use of maximum power point tracking compared to fixed optimized load resistance increases the annual yield by 20 to 35%."
www.hindawi.com/journals/ijp/2017/7540250/
Very cool experiment. Great potential for households. Imagine everyone having renewably powered heated water and thermal mass floors? My question or comment is about the equal square foot between the two competitors. The solar PV electric water heater has multiple times as much surface area contrasted to the solar thermal water heater. You've done a nice job here!
In an upcoming video I will be comparing different arrangements of PV for optimization. At the end we can normalize for area. I will provide all data so we can learn together.
Sounds great. Good work!
I just love your enthusiasm .
Has anyone thought about a hybrid where they add glass over the solar panels for heat capture somehow and be able to use the solar? Obviously would need to use unglazed glass to let the uv through but may work?
So what is the result? I have small house on the Sea area, temperature doesn't go under zero Celsius almost all the time on winter. I want to make some kind of boiler or solar panel to heat the water on winter but also i want to make it sure that it doesn't cracks if temperature goes under zero Celsius..., So im thinking also what is better, solar panel that makes electricity and then electric heater, or simply solar heater or boiler...
Won't the hot water panel drain every time the controller shuts the pump off? And then won't the panel warm up faster then cool down quick because of the injection of cool water. the way I'm kind of understanding the system works with that controller is that water would need to sit in the panel and heat up and then that water would be injected into the tank so I would think you would need to have a check valve holding water inside the panel so that it won't drain every time the controller shuts the panel off when the tank is warm enough or the panel is cool enough.
The controller won't cycle very often, only if there is a long period of shading, or after the sun goes off the panel. You can not put a check valve in, because it won't drain back when the pump stops running, and will freeze.
I suggest you check the label on that silicone you used to seal the heating element. Even though the big words says "100% waterproof", I think you will find that the fine print says it's unsuitable for continuous underwater use.
OK. I've already finished the test and emptied the barrel. It was 100% waterproof for a month. Thanks for watching.
@@DavidPozEnergy I see, I assumed a test like this would go on at least a year, to get all the seasons, and maybe even be a permanent installation.
I saw a video that someone had solar and programmed it that when the battery are full the low voltage DC water heaters would get the power not needed. If you had wind generator with your solar the good wind controller has resistors to use the power not needed, wind generator can must have a load to keep them from over speed. Just an idea may not be something that will help you. If it isn't something you can use just trash it. I don't know what all you have and need. Just had the thought and pass it on.
muito bom
to give you people an idea, on an overcast day, the PV made 25% max output, the vacuum heat pipes at the other hand only 4% of max.
Putting the barrels right next to the solar collector gives it the best chance. I still stand by my last prediction at this point, that the thermal will achieve 100 degrees sooner than the resistance element powered by photovoltaic panels, but the electric, over time, will finish at a higher temperature. The only thing that concerns me, is in low light, the panels will suffer voltage drop. They are constant current devices, so a little loss of light will greatly reduce the power available to the water heater element. A maximum power point tracker, or even a simple pulse width modulator, that will throttle back when the panel voltage gets below a threshold will put more average energy into the element, with varying light conditions. Adding more solar panels will help in low light, but you're leaving a lot on the table when there is bright sun. The Thermal panel will exploit the bright sun, putting it ahead. It's tough to match a Photovoltaic panel to a pure resistance, with varying light conditions. Very narrow operating window.
I agree that it is hard to match PV to element. My next video is going to be dedicated to this topic as I had a hard time figuring it out.
@@DavidPozEnergy Yes, you'll need an mppt controller or dc-dc boost or buck converter with enough grunt to keep the panels at their mpp while also driving the element at its optimum too.
A controller may expect to work with a battery just to complicate things.
Connecting the element directly to the panels would just pull the voltage down to a few volts and you'd get next to nothing out!
I don't know enough about MPPT controllers that can work in a direct setup like this. I've been watching some of Opera's videos because he makes some, but I just don't know enough about electronics yet.
@@DavidPozEnergy You're on the right track, to just build the rig, and adjust by trial and error. Without data, I'm no help. There's only one way to get the data: Experiment! one thought to simplify things, Connect the water pump to a small photovoltaic panel, on the same plane as the thermal panel. If there's enough sun for the pump to run, there's enough sun to heat up the thermal panel. Automatic, with no electronic controls. On a bright hot sunny day, that pump will really get going, which is necessary to control temperature rise within the thermal panel. Again, it's the matter of choosing the optimum size photovoltaic panel to run the pump only when there's enough sun to heat the other panel.
@Vincent: I thought about a 12v solar PV panel to run the 12v pump. My understanding was they can increase risk in my setup. I address this topic in the video at 23:17. I may have missed something as I've never built a pump directly connected to a panel.
Definitely interested in the outcome. I have a large hydronic system, that i picked up cheap. I bought it for the pumps, heat exchangers, and controller, to use with a wood fires boiler. I have become intrested in running the wood fired boiler in the winter, and the hydronic system the rest of the year, to provide domestic hot water. With the drop in cost of PV, it might be an option, since there is a significant reduction in complexity.
Sounds like a good setup. If you build it, I'd love to see how you set it up.
This experiment will definitely help me out...I bought an off grid place, it has two large 4x8 panels that had glycol in them....they were on the roof ...the next owner moved them to the ground....They also left two hot water tank elements/12volt behind...looks like they were in the process of using both systems....So now I'm curious to see how this works out...they had two hot water tanks /one was propane and they other looked like a pre heat tank where the glycol piping ran into the tank...once that water was preheated it went into the hot water tank....they also had a cook stove hot water tank connected to the system...I'm not running any of it at this time as there's piping running everywhere...and I will need a plumber to take a look at this mess...And everything is marked or written in German...
Wow! That sounds crazy. I'd love to see a picture of the "Before", and later when you work it out an "after". Do you have any pictures on facebook, or e-mail?
I will be down there again in a week or two.....I do have some pics and will take some more...I took 92 batteries off the property (as he had passed in 09 and his wife and daughter only went there in the summer and the place was falling into disrepair) ...you wouldn't believe what this guy was doing...he passed away before he could complete his projects...He was a CEO of a telecommunications company in Germany and I guess going to retire here in Nova Scotia and he had a place in upstate NewYork finger lakes area?... I have a very old computer and cant attach pics right now but I'm working on it lol...Is your email on this channel....I will try and attach some pics in a few days...I will send you some pics and you will either shake your head or will be amazed at how this guy had his solar system set up...
You can send me an e-mail through my website: www.davidpoz.com/contact or message on facebook: facebook.com/DavidPozEnergy/
How many watts are you running to the element.... I'm sorry if I missed it.... How many watts is the element rated for... And lastly do you need a thermostat.... Thanks brother you're amazingly AWESOME....
The electric heating element was a 2000 watt model, and I ended up connecting it to 1,095 watts of solar panels. I have more info on that in this video: ua-cam.com/video/kVaxAfXQPDU/v-deo.html
Hi David did you follow up with another video about the comparison between PV and solar thermal hot water heating?
Thanks for doing this
Yes. There were a few video in the series, but if you want to skip to the end, here it is: ua-cam.com/video/KVeGummoXS0/v-deo.html
If it was a closed system and you criculate the water it would work alot better because the water the pipe/ close loop will become hotter
Great effort but more insulation needed around the barrels and pipes. Better pump maybe? 😀
Sorry, I had to skip an ad. It was 14 Minutes!! UA-cam is out of control. I always let ads less than 2 minutes go as a way to fund the channel. I realize you may not have any control over the ads but just wanted to let you know if you did have influence. I enjoy your channel and will always let a 2 minute ad play to help out a little bit.
I'm not a YT expert. I know how to turn on monopolization, or turn it off. I'm not aware of any other controls, if there are some. I would have skipped a 14 minute ad to, so I'm with ya.
DavidPoz i just penned the video again tonight and ... no ads. Hmmm. Tonight I am casting from my iPhone. Last night I was using the UA-cam app in Roku. To comment I have to use iPhone/iPad/web browser but the ad occurred before I logged on from phone. It’s no big deal really except I hate to not give you good channel providers credit.
On the other hand, this was a very interesting video since I always thought hot water heat, not PV was the way to go to heat water. Caused me to rethink my hot tub project. Thanks for al your work to make these videos good to watch and educational. I like to call this UA-cam University. Haha
Oh, when I posted before I forgot to ask what the wattage of the electric heater element was. Considering the PV panels have limited output before voltage drop it would be a consideration to have enough panels (200 watts each?) to match the draw of the element so it works to it's ideal range when the sun shines.
My next video will be about the electrical hookup. Thanks for watching.
Hi rupe53, This is a 1500 watt @ 48 volts. I think I linked to it in the description if you want to see more details about it.
BTW, older comments are hard to find. UA-cam notified me that you made an edit, but then I had to scroll through trying to find it. This might get lost in the shuffle, so if you don't mind, make a new comment. That way UA-cam posts it at the top of my account and I can respond quicker. Thanks.
Would there almost always be a significant temperature differential? The test is a good idea.
I'm happy to help, but what two things are you asking if there will be a difference?
Apparently I wasn't the only one?
That thought.
You were taking the long way around the barn ...
I'm sorry, I don't know what you are referencing. I'm happy to try to help if I can.
My guess, before watching the video would be that thermal will outperform PV in efficiency because PV has only an efficiency of roughly 20% (the left over 80% get turned to heat on the panel).
So why don't we see an experiment to collect heat from the back of the electric solar panels ? There was an experiment in the Middle East to determine how much energy is lost by the background such as sand or dark. Reflective was not tried, and putting solar hot water heater on back was not tried.
Ever consider just using a couple tie down straps to strap the barrel down to keep it from rocking? Those boards can and probably will still warp/twist/swell over time! Tie downs least keep it sturdy and less chance of ever tipping or falling over for any reason?
Thanks for the suggestion.