The Energy Family Makes A Solar Hot Water Heater

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Step 1:Zack Tennyson (left) and the author lift one of two solar collectors onto homebuilt brackets. Glycol in the collectors is heated by the sun.

We do appreciate the technology, though. Before we installed our propane water heater in 1999, we were living with cold showers--a rough situation up here in northern Vermont. The hot water was a luxury. For two days, we even argued over who got to do the dishes. Since then, we've managed to empty our propane tanks every nine or 10 months, for an annual hit of about 550 gal. of fuel and as much as 1000 bucks.

When it came time to try something better, we quickly decided on a solar hot-water system. To most people, "solar power" means photovoltaic panels that produce electricity. That's a shame, because solar hot-water systems actually make better use of the sun's energy and offer a quicker return on the investment, which can range from about $6000 to twice that. "It baffles me," says Peter Allen, founder and president of Thermo Dynamics (www.thermo-dynamics.com), a Canadian company we turned to for help with the project. "A kilowatt of photovoltaics costs about $7000; a kilowatt's worth of hot-water system is about $2000."

17. RE: The Energy Family Makes A Solar Hot Water Heater
I've been staying at an ecolodge in Southern Laos. Granted, the weather here is very conducive to anything solar, whether you plan it or not. But the passive Chinese-made solar hot water heaters are amazing. I took a shower last night a full 3.5 hours after sunset and I had to mix in some cold to get it to the right temp. The insulated reservoir contains 160L water; the system is controlled using a float valve much like a toilet tank. Water is circulated by natural convection: ie, no moving parts, no fancy working fluid, nothing. The owner bought his heaters for US$400. Some interesting links: http://www.worldwatch.org/node/5060 And: http://www.environmentalgraffiti.com/sciencetech/china-solar-hot-water-capacity-soon-to-be-equivalent-to-40-nuclear-plants/822 These ought to be Made in the USA.

16. RE: The Energy Family Makes A Solar Hot Water Heater
I was thinking of a polished aluminum shallow walled box w/ glass top, loop copper all thru, run a closed loop back to a baseboard heater using a solar powered pump. I thought that the water would heat up enough and the baseboard heater would act as a heat exchanger. What do you think? Mike

15. RE: The Energy Family Makes A Solar Hot Water Heater
Regarding response #7: On demand water heating to 130 deg F is not very feasible using a solar water heater... Regarding response #10: A great reason not to use solar generated electricity to heat water is because of the amount of energy it takes to heat water. Let the sun do it directly. Regarding response #2: A good reason not to use PVC is because it doesn't conduct heat very well. The sun would heat the outside of the tube and that heat would have to transfer through the PVC to the water, losing energy on the way. Copper conducts heat very well and is relatively cheap...

14. RE: The Energy Family Makes A Solar Hot Water Heater
Has anyone noticed the proliferation of news articles professing the "real costs" of 'something' and in the real world the cost is much less before the 'news article' than after the article. Solar hot water heaters can be made very cheaply. Hundreds of dollars, not thousands with materials easily gotten from 'home' stores. Alot of people make solar heaters out of recycled materials for next to nothing.

13. RE: The Energy Family Makes A Solar Hot Water Heater
have you ever thought of acctually making a solar hot water heater using old 30 gallon hot water heaters and a sliding glass door? Its simple look up in mother earth magazine it works and costs next to nothing.

12. RE: The Energy Family Makes A Solar Hot Water Heater
please help me build a solar panel of some kind with materials i can get cheaply either for hot water or electricity -problem retired on fixed income-thank you

11. RE: The Energy Family Makes A Solar Hot Water Heater
Website: www.lumossolar.com
An evacuated tube system is more useful for these sunless northern environments. It is more efficient in marginal sunlight be it shade or cloud cover. Also for a bit more enviro friendly system consider a drainback system using distilled water rather than GLYCOL. Lumos Solar makes a good DIY kit complete with nearly everything one might need. They do flat plate collectors too.

10. RE: The Energy Family Makes A Solar Hot Water Heater
Website: www.maxgrace.com
This may be a dumb question, but if I'm switching to solar electricity, why not simply install an ELECTRIC hot water heater for $500 and skip the SOLAR water heater ($3000 and up)? A sincere question... thanks.

9. RE: The Energy Family Makes A Solar Hot Water Heater
You are making this to complicated. If the water coming out of the solar collector is warm enough, you can heat your hot water the same way it is heated with an outdoor woodstove. A double wall pipe is plumbed from the water heater drain and back into the cold water inlet. The water that comes from the woodstove never mixes with the domestic water. The drain is removed and a new one added an elbow below the heat exchanger tube. The double wall tube is a tube within a tube, the water from the hotwater heater exits where the old drain was, this is the inner tube, it elbows up and goes inside the outer tube, this is the hot water from the woodstove. The cooler water will naturally circulate up the pipe to the top where there is another elbow that takes it to a T where the cold water enters the waterheater along with the cold water from the well or city source. In the winter when I use my outdoor woodstove I turn off my electric waterheater and I never run out of hot water. The water from the woodstove has a pump that runs all the time so hot water from the woodstove is constantly circulating which heats my hot water and my house. Instead of a woodstove I was wondering if the water from the solar collector would be warm enough to work the same way, I could use this during the summer months to heat my water.

8. RE: The Energy Family Makes A Solar Hot Water Heater
could you hook one of these panels up to an old school radiator for a constant source of heat ?and what would i need to pull this off ?

7. RE: The Energy Family Makes A Solar Hot Water Heater
Website: www.circlex2.com
To make it even more efficent they should have used an on demand water heater. The up front cost would have been at least double but they would only be heating the water up to 130 when needed instead of all the time.

6. RE: The Energy Family Makes A Solar Hot Water Heater
this is really great making your own energy to power your house and it helps the environment

5. RE: The Energy Family Makes A Solar Hot Water Heater
I have read your story and am very impressed. I have been researching ideas for electricity alternatives as well. A couple of ideas are 1 an alternative to dry clothes as we have a large family and the other is refrigeration. As for the clothes dryer I have considered a home built wardrobe with a low voltage fan, powered by solar of coarse, blowing across a heater core that is heated by the solar water heater. An automotive heater core can be purchased for $20 to $30. It would likely take much longer to dry clothes this way and they would need to be dried during peek hours, however, it would be free and your clothes come out of the dryer already on a hanger. This is just an idea that I have thought about expermenting with. I don't know if it is realistic or not. If you would like to you can email me and I will share with you other ideas on heating, cooling, refrigeration and more. I am not an engineer or professional in this area by no means, but I have put some time into researching ways to conserve and your story is truely awesome.

4. RE: The Energy Family Makes A Solar Hot Water Heater
Rheem makes a water tank with a heat exchanger in it. An optional back-up electric element also. See model rhm80hx ( 80 gal). About $999 us.

3. RE: The Energy Family Makes A Solar Hot Water Heater
I suggest that "a heat transfer coil that can be installed in the place of on of the electric heaters in a hot water tank" by threading 50' of 3/8" copper tubing in thru the top probe hole and down to the lower one coiling remainder in the tank. The 3 or 4" tubing ends to the tank can be sealed by compression fittings put on in reverse with reducer pipe in the openings. That way leaks can be monitored and less chance of contaimination. Use a string-small weight in top opening and capture the weight of your fish line from the bottom. I say 3/8" because: 1. easy to bend and coil. 2. fluid will give up heat longer / faster with lower pressure and flow. 3. Use lower pressure in tubing than water pressure to reduce tubing flex and cross-contaimination.

2. RE: The Energy Family Makes A Solar Hot Water Heater
Why not just just paint some pvc pipes black and run a loop from a pump straight back to the tank inlet on the water heater? If covered with a pane of tempered glass, it would cut wind cooling down and maybe magnify the heat gain. It would be a lot cheaper and any decent DIYer could pull it off!

1. RE: The Energy Family Makes A Solar Hot Water Heater
Would like to know where to obtain a heat transfer coil that will fit into a standard 50 gal hot water tank so that I can utilize a solar hot water collector, a solar powered liquid pump and water mixed with anti-freeze in the collector portion of the system. This way I can directly heat water in the 50 gallon hot water tank without having a second hot tank for the heated fluid from the collector. A balast tank will be used for expansion of the heated fluid mix. So does anyone manufacture a heat transfer coil that can be installed in the place of on of the electric heaters in the hot water tank. Thanks for any help. - dan

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