In Februrary of this year after a nine day power outage, I began to rethink how we get our utilities and how I could have more control of my own destiny, or at least my own power and water. I live out in the country and surprisingly I have no propane or natural gas. My home is all electric. I had an undersized electric water heater and was trying to decide if I should invest in a propane tank and all the plumbing to get the gas in my home as well as putting in a new larger propane water heater or a tankless water heater, or if I should invest in solar hot water. I decided to jump in feet first and went with solar hot water. I did research online and spoke to a 
few local installers/retailers of the equipment and decided what was best for our climate and situation is a closed loop, non-drainback solar water system. The closed loop part is a propylene glycol & water mixture ( so it won't freeze) that is pumped through 2 flat plate collectors (large panels above) on our roof then through a heat exchanger in our water tank in the house. The glycol mixture is pumped through the system with a small DC pump powered by a PV (photovoltaic) panel. (The small panel to the left of the collectors) So when the sun is shining and heating the glycol, it is carrying the collected heat to our water tank, and at night when the glycol cools it isn't pumped through the tank carying heat out. Inside, the glycol pump, glycol loop expansion tank, cold water expansion tank, shiny new 80 gal water tank and lots of copper piping and is housed. There is a small electric element in the top part of the tank as a backup for cloudy days. I also installed a temperature gauge on the incoming and outgoing glycol pipes to see how the system is running. So far on a really sunny day the incoming glycol temperature has reached a whopping 210 degrees. There is a tempering valve set at 140 degrees on the hot water output of the system. 140 degrees is the water temperature most dish washers run at so we typically don't have to re-heat water with the element in the dish washer.
few local installers/retailers of the equipment and decided what was best for our climate and situation is a closed loop, non-drainback solar water system. The closed loop part is a propylene glycol & water mixture ( so it won't freeze) that is pumped through 2 flat plate collectors (large panels above) on our roof then through a heat exchanger in our water tank in the house. The glycol mixture is pumped through the system with a small DC pump powered by a PV (photovoltaic) panel. (The small panel to the left of the collectors) So when the sun is shining and heating the glycol, it is carrying the collected heat to our water tank, and at night when the glycol cools it isn't pumped through the tank carying heat out. Inside, the glycol pump, glycol loop expansion tank, cold water expansion tank, shiny new 80 gal water tank and lots of copper piping and is housed. There is a small electric element in the top part of the tank as a backup for cloudy days. I also installed a temperature gauge on the incoming and outgoing glycol pipes to see how the system is running. So far on a really sunny day the incoming glycol temperature has reached a whopping 210 degrees. There is a tempering valve set at 140 degrees on the hot water output of the system. 140 degrees is the water temperature most dish washers run at so we typically don't have to re-heat water with the element in the dish washer.The electric element in the water heater is set to 120 degrees so it only comes on when its been cloudy for quite a while or if I use a whole lotta hot water in the evening. We've had the system 6 months now and have seen a noticeable decrease in our electric bill. The major components of the system should last about 30 years so, once it has paid for itself we will have lots of free hot water. The system was expensive coming in over $7000. I could have gotten a cheaper system and installed it myself, but for my wife's piece of mind, we had it professionally installed.
There is a 30% tax credit for solar water and photovoltaic systems that will help come tax time, but yes, it was costly, but definitely worth it!
Here are some handy links if you are thinking solar water:
http://www.dsireusa.org/ - this is a national database of state and federal tax incentives
http://www.suncityenergy.com/ - this is the company where we got our system
http://en.wikipedia.org/wiki/Solar_water_heating - wikipedia article on solar hot water
http://www.altestore.com/store/ - a cool online store
Yay for having it professionally installed!
ReplyDeleteDuring the ice storm, we realized how lucky we were when our mechanical water heater kept us alive.
Are you considering solar powering anything else?
Yes, I am currently powering the Gable vent fan and I've got an attic fan on order that will be powered by the sun. I plan on putting some PV panels on the roof to power everything in the house once I've tamed my electricity and the prices go down or efficiency goes up. The is a gov't sponsored plan to have panels below $2 a watt by 2015 and a few manufacturers are claiming they will beat that date by a year or more... So hopefully soon. I'm also looking at wind turbines, but don't really have quite enough wind to make it worthwhile.
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