I wanted to get a post up about my family’s solar home. I started a much longer version, but have not had the time to finish, so here is the short version.
The first step on any solar home is to begin working on reducing energy demand. Energy efficiency is a must; it makes no sense to waste energy, and the applies to renewable energy also. So all our lights are compact fluorescent bulbs (starting to look at LEDs), Energy Star front loading washer, high efficiency Bosch dishwasher, etc., etc. We had a Home Energy Rating done on our house looking for leaks in windows, doors, and air ducts. This is the best way to understand what you need to be doing in your home to reduce waste. We did work on our heat and air ducts, and some significant air leaks in other parts of our house.
We started the solar pieces as part of the energy efficiency review. First we noticed a few dark places in our house that required turning on lights in the daytime. This included a couple of bathrooms, hallway, kitchen, and a living room. So we installed Solar Tubes in these rooms. This is a form of passive solar day lighting. Check out the video of our install. These are great and really change the feel of these rooms and they are not that expensive — a few hundred bucks. Next, we installed a solar hot water heater. It’s a great addition. Makes no sense to heat water with costly, polluting, dirty rocks from the dinosaur age (coal) when the sun will do it for free. We chose a Schuco system.
This has reduced our electric bill about 20%. I’ll go into more detail on solar thermal in a later blog post, but this also is a real energy efficiency gain, and has a quicker payback then photovoltaic (PV) panels. There are many different models on the market and you can get one from $4,000 to $10,000 depending on the model and incentives. I worked with Ed Zubko at Green Earth Services on both the solar hot water system and the PV system.
The photovoltaic (PV) panels are 36 Sharp 198 watt panels manufactured in Memphis, Tenn. The total system size is 7.13 kilowatts. This is a large residential system, but we hope to use some of the power for electric transportation in the near future, i.e. plug in hybrid. We are using a Sunny Boy 7000US. We bought both the panels and the inverter from Thomas at Big Frog, who can help you with everything you need. This is grid tied, meaning we do not have batteries at this point. We are selling back to the Tennessee Valley Authority (TVA) system through their Generation Partners Program. The program currently pays 15 cents a kilowatt hour, but that is about to jump to over 21 cents. The system is great. We commissioned it February 11, 2009. We are also able to track the performance of the system everyday online. Enter “Knoxville” as the city and click “Smith 7.1 kW.” We didn’t get the Internet feed up until mid-April, so some of the early data is not listed.
I love watching the meter spin backwards. In the first month, Feb 2009, we generated 697 kWhs and only used 455 KWh, so KUB paid us a credit on the electricity of $104. Not bad. The second month we generated 740 kWh and only used 381 kWh, so we got a $111 credit. After the credit our total bill electric, gas, water and waste water was $1.39!!
Bottom line – we love our solar home. Ask me questions and we will continue to post updates. The solution to our energy needs rises everyday in the East.
Check out some of the news stories on the system.