Does solar thermal work in very cold temperatures? There is heat in light!
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- Опубліковано 26 лип 2024
- Does solar thermal work in very cold temperatures? there is heat in cold temperatures?
• How well do solar ther...
• Installation of a Sunm...
A solar thermal collector is a solar collector designed to collect heat by absorbing sunlight. A collector is a device for converting the energy in sunlight, or solar radiation, into a more usable or storable form. This energy is in the form of electromagnetic radiation from the infrared (long) to the ultraviolet (short) wavelengths. The quantity of solar energy striking the Earth's surface averages about 1,000 watts per square meter under clear skies, depending upon weather conditions, location, and orientation of the surface.
The term solar collector refers to solar hot water panels, but may also refer to more complex installations such as solar parabolic apparatus, solar troughs, and solar towers; or less complex installations such as solar air heat. Solar power plants usually use the more complex collectors to generate electricity by heating water to produce steam which drives a turbine connected to an electrical generator. The less complex collectors are typically used in residential and commercial buildings for supplemental space heating. perpendicular to the sun's rays. - Розваги
If you set a mirror in front of the unit, it would double the sun
hitting the solar tubes. If you need more heat, add a few heliostats
reflecting even more light. The fact that the heat stays inside the
vacuum tube is a great thing.
Helped a guy build a solar water heater on a boat one winter (in Turkey) about 3 years ago. Think he only wanted it for the ladies who used to visit and always complained about the lack of hot water on board. Anyway near the end of the build during the test he nipped off to town, I had to phone him for advice when steam started to appear. He told me to close it down. It worked so well he installed a radiator and hot towel rail in the heads to use up the eccess heat. My wife also got some work sowing canvas covers for the panels when it got too hot.
lol. when you said 25 degrees, i went " why the hell are you wearing so much clothes?!" then i realized ohhh, farenhieght, not celcius. lol
You use lol's like quotations marks lol
as a canadian yes haha
It's -15 here, C, and I still wear shorts.
its only -3 Celsius about its not even cold yet for people in north.
thanks everything i needed to know. Im sort of a mcgiver and wanted to heat up a 90 gallon pond. Did not know how good it works and this vid answered most of my questions. . Now to build one lol.
I'm in central British Columbia, Canada. I have three sets of 20-tube evacuated tube panels for domestic hot water and floor heating. I can confirm that these panels do heat water very nicely at temperatures down to minus 18C or so. Below that, hoarfrost on the tubes cannot 'burn' off and the water heating slows dramatically. But it depends where you live: if hoarfrost does not appear often then these panels can run at even lower temperatures. Money well spent!
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.
Im in northwest michigan in the snow belt. Ive been thinking that combineing thisnwith a geothermal loop would be massive boost in efficiency. But theory and numbers is one thing reql world is a whole different beast.
Certainly the vacuum tube solar thermal heater is very efficient. I also believe there is not enough water flow through the collector since both the inlet temperature and the outlet temperature should be within a few degrees of each other. Lots of heat is being lost.
But in the end it is my belief that solar PV is the way to go. For significantly less money I can buy 4 solar panels, a controller and have all the hot water I need. I can also use the excess power to do other work on those days I am not using a lot of hot water. And of course an 80 gallon storage tank can store all the hot water you need at night or in the early morning until the sun comes up. There are no contractors even selling solar thermal installations in my area of Arizona anymore. Everyone just goes grid tied solar panels instead. No pumps, no valves, no leaks and no freeze worries.
If you don't mind the look you can also install a few mirrors in the back and on the side of the collectors to generate even more heat.
Very important input 🙏
great, I would consider solar PV too. Both continue to come down in price.
I have a similar receptor on the roof... Besides of hot water, is there any other energy output to this system? Even if a converter is needed...
Thank you, great video
Great video . thanks.
Wow that's amazing but I wish you used *C on the other side of the pond.
Can you help me set my system up? I have some questions and I have the vac tube heaters already. Jim
An 18 degree difference in Fahrenheit temperature within the chamber is significant. If you can claim it by transferring it back into the pool at the proper rate, then I love this system.
I swim at a indoor pool, Centennial Pool Longmont, CO, that has installed solar tubes for supplemental heating. We have had three and four foot snows with no problem with snow accumulation on the tubes. The tubes are simply at the best angle for catching the most heat. Snow simply falls through the tube set up. The outer glass is envermential tempature so there is no ice buildup. Any frost quickly melts as soon as the sun comes out since there is no mass to hold the cold. Of course there is a fence with a hedge to keep the collectors protected and concealed. Talking to the maintenance man he tells me the collectors have reduced the gas needed to heat the pool particularly in winter. Again, no snow build up, most effective in winter. And yes bellow zero winter weather at times.
Salaams brother (Peace Be upon you) nice job. Now we just need a home to with this great opportunity when we head back to Michigan, GOD BLESS your hard work. Insha'Allah we will contact you soon.
So last year, it got to about 6 deg F here, and historically, we've gotten below zero. How long does the water stay hot theough the night?
2 Comments: 1) Thank-you. I appreciate the details in your presentation. 2) Your title is misleading. Barely getting below freezing is not "very cold" and though your numbers are interesting, they do nothing to help assess if these tubes actually work in "very cold". When temperatures stay around -20C (-4F) for several months (dipping to -40C), I'm trying to find evidence that there isn't some operational curve where these tubes stop creating a +50C differential between ambient air and heated water. For the record, I'm not citing temperatures from the arctic. I live 6 miles north of the US border. "Canada's Hot Spot". The prairies get hot in the summer but cold in the winter. These are normal, seasonal temperatures that we need to work with.
Ed Hammerly of New Jersey renewable energy forgot to mention some important points in his video on Sunday Feb 03.
I find that most green energy folks always forget to mention reality and how it actually works, especially when talking about solar water heating systems or electric cars in cold climates with one to two hour commutes in rush hour traffic like in Chicago when it is 10 F - Fahrenheit or colder with the heater running full blast.
Most home hot water heaters are set at 120 F for a reason. Legionella bacteria (i.e., that can cause pneumonia and mild flu like illness called Pontiac fever) can grow in water temperature between 68 and 122 F. And, most people like to take showers that are around 100 F. My wife prefers 105 F. We would be very unhappy having to take showers at 75 F to 89 F. Our hot water heater is set at 140 F, which is probably 20 degrees above average.
Ed indicates that the water tank is 80 gallons. At 12:30 pm, the temp in solar collector is at 138 F, the temp in the tank at the top was 79.5 F, middle 64.4 F, and bottom 62.8 F. By 2 pm, the temp in the collector is 138.9 F; the water at the top of the tank is 88.3 F, in the middle 72.9 F, and at the bottom of the tank 72.0 F. By 3 pm, the collector is at 115.9 F (a loss of 23 degrees F or 16.5%) the top of the tank is 88.2, the middle 79.0 F and the bottom 78.6 F.
Ed then states that we have gotten a free tank of hot water; he should have said warm water (80 F to 85 F) and stated the actual cost. It was not free.
energy.gov/energysaver/articles/solar-water-heaters
“Doing the Math on Solar Water Heaters”
A solar water heating system cost from $8,000 to $10,000 for households with four to five people.
Assuming an average life of 20 years, that is from $400 to $500 per year, before maintenance. The average energy bill for a single family home is about $2,200 per year. Of, this 14%, or $308 per year, is spent to heat water.
www.americanthinker.com/2012/06/doing_the_math_on_solar_water_heaters.html
Ed also assumes that no one is taking a shower in the afternoon on Sunday or washing clothes. An average 10 minute shower can use from 25 to 50 gallons depending on your shower head. A fully loaded washing machine uses 25 to 35 gallons. A dishwasher uses about 3 gallons. If you are running these after 3 pm in the afternoon, you will run out of warm water.
askville.amazon.com/gallons-water-average-10-minute-shower/AnswerViewer.do?requestId=2548818
homeguides.sfgate.com/many-gallons-water-average-washing-machine-hold-full-80612.html
Ed also forgot to show up what the temperatures in that 80 gallon water tank were at 6 pm or 8 pm, 10 pm or 6 am the next morning. My wife and two children take long showers before going to bed at around 10 pm. Sometimes, my wife and I use the about 50 gallons in our whirlpool tub in the master bathroom in the master bedroom. We have a 75 gallon hot water tank that works wells, which reheats sufficient amounts of water for all those activities.
Ed forgot to mention that if you do take showers at night or in the morning, you will need a back-up water heating system (i.e. gas or electric) unless you like taking cold showers.
Anyway, I have just explained the reality of solar water heaters in cold climates.
Well… George. I don't think I have the time to go over point by point on your book report, but you make a few valid points and concerns. I'm not sure why you think I don't have a back up system to make hot water when my solar system is unable to perform the job completely. That said, the technology has many great advantages and will become more viable to more Americans as prices continue to come down. For now, in many cases, as the world calculates costs, its not the cheapest alternative. I'd argue that the installation cost is what tends to drive up the price. But what many people don't want to admit is that we can keep doing what we have been doing. The environment and finite resources won't allow it. The cost of doing things the old way aren't included in the price of your fossil fuel devices. Human health issues, environmental damage and military costs in dollars and lives securing these resources across the world. As seen in the Ukraine recently, many european nations are stuck between a rock and a hard place, because of Russia's control of the natural gas in the region. Sustainability is going to be the word of the next century.
Yeah I'm not reading all of that.
I agree with most of what you say. Yes a system like that cost much more than just using fossil fuels! But I have to say that when I researched the average 10 minute shower it was 10 to 15 gallons. I can't imagine what a person would look like if they showered long enough to use 50 GALLONS... Must be a typo since most homes I have installed water heaters in were 30 gallons. I have done one or two 40 gallon but "Holy Science" for someone to need a 70 GALLON tank is ridiculous. I think you are the most water wasteful person I have ever heard bragging about it. My wife and I had a grey water system and our average DAILY use including; Shower, bath sink, Kitchen sink. came up to a whopping 15 gallons per day. You must let the water run when you shave and brush your teeth. Also, it's not that difficult to turn the water off while washing your hair and while washing your body. I let it run the entire shower if it's really cold in the house but most of the year I turn off for hair wash and off for body wash and it takes far less water that way.
George, everyone, the only safe way to use Solar Thermal with potable hot water is to heat the storage tank from the top-down!
For example, the heat exchanger systems that use coils inside the bottom of the tank may not provide hot enough water. Therefore, it is best to have a second coil at the top of the tank. The hottest antifreeze enters the top coil, exits, then enters the bottom coil, then back to the solar collector.
A set of thermostat-controls are also essential for controlling a couple pumps. There is no point in circulating the antifreeze until the temperature at the collector exceeds two temperatures: 120-140 °F (typically what is set on hot water heaters), and Also exceeds the hottest stored water by at least 10 °F. It may be best to use a proportional speed controller on the pump to at least maintain that temperature, so I recommend a DC motor.
If using an external heat exchanger, place the heat exchanger at middle of the storage tank to heat the potable water.
When the potable water exceeds the setpoint *and* exceeds the storage tank temperature (at the top), pump it into the *top* of the storage tank. This can also be a proportional speed pump, Or, the circulation may occur by *thermo-syphon* Feed the heat exchanger from the tank bottom. Also, heavily insulate the heat exchanger, pipes, and fittings.
This provides hot tap water that is safe to draw from the top of the storage tank. Finally, the storage tank temperature may far exceed Scalding temperatures, so use a mixing valve!
Really? It is possible to go to home depot and buy the parts to construct an inexpensive solar water heater with copper piping for a couple of hundred dollars, my dude. Furthermore one can make a water heater storage tank that is vacuum flasked so that it will store the heat nearly indefinitely.
Also how much money does our government military industrial complex spend every year combating the effects of global climate change due to the carbon emissions from fossil fuels, how much money do the U.S. and other spend to fly jets spraying heavy metal aerosols to reflect sunlight to lower surface temperatures on earth. How much do individual Americans spend treating respiratory illnesses from breathing in heavy metal aerosols, the rapid rise in degenerative neurological diseases and autism can be tied to increases in weather modification programs.
So before you start analyzing just how much it will cost to heat a home with solar, just think the Trillions of dollars the world has spent just so people can get a cheap gallon of gas, the trillions spent combating the effects of global climate change with weather modification programs, the money spent fighting forest fires due to increased temperatures and increase air conductivity. The billions of dollars we may have to spend to address rising sea levels and it's effects on coastal cities, mush of Florida will be underwater.
Why don't people factor in the actual costs of using fossil fuels?
ua-cam.com/video/TDvLCPe8viU/v-deo.html
hehe this video made me remember 50 years ago when i had gotten a glas bottle of coke with me to our local beach.
it was in the spring and quite chilly,,, but i love my coke COLD.
So i layd my bottle in the water arond 1 feet deep that was almost to cold to swim in,, but it was a cool SUNNY DAY..
After 1 hour ore so i got the bottle out of the water and it was to hot to hold with bare hands. hehe
so yes it worked,,, but for a solar heat collector to work 100% in cold climates its best to insulate the the heating part in cind of like a greenhouse.
normal cheap insulation on the backside... and double layer insulation GLAS on the sunny side.
21st century & still some people still need to be convinced. ANY car, in a winter climate, on a sunny day….WARM. SCIENCE!!!
This is nitpicking a bit but there is no heat in light. You can convert the energy in light into heat (solar thermal), or electricity (PV), or chemical energy (photosynthesis).
Why is the temperature in the collector so much hotter than the temperature in the storage tank? A solar thermal collection system is most efficient when the collector temp is as close as possible to the water temp. The collector efficiency goes down as the temperature rises above ambient so you want to see the collector only a few degrees hotter than the water in the tank.
A smaller water tank would have you right where you need to be, or just get a bigger grid and insulate it a bit more.
The snow and mountain images I posted in this video are from Antarctica. As long as you followed the design parameters for you specific location, it would work. Keep in mind, the light that lands on you traveled millions of miles through space. It can surely handle -40 degrees, ;)
These look good for people who live in places where there is lots of sun, but what if you don't get much sun what kind of result would you get, presumably very poor.
At lest it is testable you could try it in the shade, but living where the sun don't want to shine or is always kept away by polluted clouds means other ways need to be found.
But these look hood for those who get lots of sun.
Yes, more sun the better. However, you would be surprised how well they still work in light cloud cover.
Great idea for areas that see little to no snow. My location averages 75 inches of snow that would have to be cleaned from the collector. Not to mention the ever present clouds that bring that snow. Good idea though.
You make it sound like the 75 inches of snow all fell at one time. How hard would it be to brush off an inch or two of snow on a ground-mounted collector, assuming it even stuck to an angled, rounded surface?
woodledog Snow adds extra work to something like this. It's not only after a storm but drifting can cover the collector with snow that is difficult to move.
I've seen panels like this mounted vertically on the side of the house (in Wales!) and the owner assures me that the hot water he gets from two of these panels is well worth the investment.(He has solar-pv panels on the roof!)
John Benton Panels mounted vertically still get sunlight but no where near as mush wattage as if they were mounted at angle. The payback period would certainly increase, maybe worth it, maybe not.
The vertically-mounted panels are solar-thermal, with the solar-pv panels on the roof. The owner of the property (as of 2 years ago) was consuming less than 10% of the house next door. So he was saving over 90% on his electricity bill. All his panels were installed by the owner (who is a very skilled sort of chap) and the original plan was to run a 6-room B+B without paying for his electricity. He hasn't quite managed it but a 90% saving is not to be sneezed at. (He also boasts an unlimited shower service for his guests - and they are very good showers!)
Why don't you put that unit in a box with plexi-glass? I would think that it would get hotter and would keep it warmer longer.
Wonder if that's cost effective ? I think adding a few more solar panels would be better, that would produce more power to supply electricity to the water heater. I run a complete electric house in NJ. Zero bills until I reach Nov/Dec into March. I need to upgrade to the 400+ AC panels to cover our power needs. 19K isn't covering everything.
Any idea is anyone has done a solar water furnace?
George Lewis states that these cost $8,000 to $10,000 to make and install. on a DIY system, it would be hard to get to $800, maybe $1,000 if you bought a new water heater as a storage unit for inside the house. even at $2,000 for all new parts at retail, the payback would be in green energy and lower use of fossil fuels. assuming a pre-heater storage tank of 85° and a final storage tank of 115°, just cutting down the energy by half wold still pay you back. but in the summer, the problem is reverse. the tank gets closer to 185° and you have to shed the excess heat.
bottom line is that even with a 5 or 10 year payback, the reduction is fossil fuel use is worth more.
I have never seen these cost $8-$10,000. A 25 tube unit costs around $800-900USD. Now you may need to add in around $200-400 for a stand if you want a ground unit. You will need some pumps, but those are small. The only way for a system to cost that much is if you are using a full system with geothermal. IE, geothermal water tubes in ground heat water to aprox. 50F, then to the solar tube, then to a heat exchanger hot water heater which can become expensive, but are not really always necessary unless you want to store large amounts of hot water for radiant heating, which in that application would be a better way to go. These work pretty well. And the crappy (Older) model he has no reflectors behind it, so he is only collecting half the light per sq area due to space in between the vac tubes. The new ones have these and reflect light in a near 360 degree around the tube, making them much more efficient and hotter achievable temps. And NO I don't have any affiliation...lol. I have been just doing a lot of research on them. Great stuff
SuperDaveisme Thank you for your input. Tell me this, could the energy from these collectors be converted to the house as a whole, and not just to the heating system, or the hot water heater. This would apply to a home in the southeast part of the US, that consumes approx 750 kw during the fall and winter months, and approx 350 kw during the spring and summer months. Could a DIY collector be wired into or work in conjunction with the standard electrical set up, and or have another meter that would calculate and send the access back to the local power company. If so, how long would it take to get to the break even point on this investment ?.
shed the heat into electricity
How about some data what it does over time, winter month averages
Can it work when it is cold and cloudy.
There is a 3.44 psi difference in air pressure between air at 25 F and 138 F in a sealed container such as the space inside of a compressed air engine cylinder. 3.44 pounds per square inch amounts to 4187 pounds of force on a one meter diameter piston. The maximum Carnot efficiency at that temperature difference is only about ten percent but it is twenty to thirty percent at typical summer temperature differences. Heating up the air with concentrated solar after it has been preheated by the panels might greatly increase the theoretical possible efficiency of such an engine. But the Carnot efficiency limit might not apply anyway because it is not a sealed up system and there is no compression stroke. The speed at which it can operate only depends on how fast the heat can be transferred. With the piston only moving one meter per second with an average force of 2000 pounds on the piston, the engine would put out about five thousand watts average.
have u moved it to ur Roof? mine are at ,on FB, "Guilt free Hot Water" page
Airgain wie feel that Americans do not know, that outside the states other countries do exist :-(
Do you think a system like this would heat the water consistently enough to heat a hot water radiator system in a 125 sq meter home where the average daily temp is 45F?
I would say yes, but you’d have to match the proper BTU required.
The system would function better if set up to use liquid metal rather then heat water!
What about at night when the temps drop down to -20°F. Frozen pipe that’s what.
Conny Bjaaland, depends. The vacuum tube systems can circulate enough (backwards) to avoid freezing in the manifold or circulation pipes. Or, a drain-back system will empty out until the manifold exceeds temperature in the storage tank.
Those tubes have antifreeze in them and a heat exchanger in the tank
"its about 25 degrees out today" and he has a coat on jesus, thats a heatwave in the UK lol
+Lebalusch Pretty sure he's talking celsius, in fahrenheit thats 77.
+Lebalusch ... 25F, which given his data shown on the laptop (that's in Fahrenheit ), is -3c. Now as someone that's lived in Northern Canada for a while, where winters get to -40F/C, I don't think -3 is a heatwave for you.
Works great in very cold climate... -3*C is a cold climate? Come to frikking northwestern Ontario in the winter and tell me how that solar heater works when it's -40*C at night and -30*C during the day!
i think the snow would be more detrimental to its performance
Rachel Brinkley, that's right. It is best to keep the bottom of the vacuum tubes higher than the snow drifts. Also best to keep them near vertical. Still have to sweep off sticky snow. Maybe RainX™ would help.
Really cold... You sure as hell are not in Canada. Well you many in the Vancouver valley.
How well does it work at -30 to -40???
It will work in the arctic. Light turns to heat when it strikes an object.
So whats the cost of something like this
unfortunately, with fracking bringing down the cost of gas, solar thermal isn't too cost effective at the moment. A residential solar thermal system might run around 8k or so.
Sorry, but did you say a tank full of 80 degree water? You need at least 100 degrees for a comfortable shower. Not seeing how this is an advantage over my natural gas heater that costs very little for piping hot water 24/7 when it's 4 degrees outside.
Eric, sometimes my buffer tank water is well over 120 degrees. At that point, I add cold water. When the tank is below comfortable shower temperature, the tankless system will heat water to needed temp. You're still getting all the BTU savings.
You could heat water from 55 degrees in the city water to 120, or you could heat it from 88 degrees to 120. Which takes longer and much more energy?
62 degrees isn't exactly stellar when tap water comes in at 45 degrees in winter already. And that's on a sunny day.
Which means on a cloudy winter day you have absolutely 0 gain from the thermal solar system.
Fact remains that solar thermal is only useful, effective during spring and fall, summer to lower energy costs.
It does not provide real energy benefits during winter.
If that was the point you were trying to make it is moot. Good video and data, very helpful. But the point is lost in my opinion.
At least if the point was about water for central heating and hot water.
I guess for a pool any and all is a good help. It's a luxury not a necessity.
BTUs are BTUs, not sure I see your point. Yes winter will have less available BTUs due to shorter days and angle of sun, but I can always put that heat into a buffer tank.
What happens when it's dark? Doesn't liquid freezes and crashes pipelines?
No, the insulation causes the temperature to drop slowly.
LIGHT IS ENERGY
Why can’t America come into the twenty first century and use metric and deg C?
yea. would not work here. not much sun light, and -numbers in temp.
They use it in the Antarctic.
I doubt it
Mike Warren
Have you ever seen ice melt even though the outside temperature is 15 degrees F when it is sunny? Look for it when we are there again with the temps low and it is sunny with ice somewhere. As mentioned in the video outside air temp changes NOTHING with the strength of the suns rays.
steve b dispute the meaningless insult . here is Michigan
that looks like about a $1,000. unit. far outside the budget of most middle class people and not ever possible for most working class people. ...... Free 80 gallons... Ha Ha ha ha ha. you will never recover the extra expense you paid for that thing, and most solar water heat systems require a "NORMAL" water heater as well - meaning that you didn't just spend $1000 bucks on that thing but $400 or $500 on your original water heating system (if you installed yourself....more if you had it installed)
Bad sound
So doesnt it freeze and break at night? How is that prevented?