Posted by: Engineer on 2007-07-15, 17:26:55

I designed and installed my own grid-tied solar system on my house, which was built in 1973. I have a degree in engineering though and would not recommend such a project unless you have similar training. Even so I used a licensed electrician to do the final wiring for me. Therefore you should be looking for a reputable solar installer. I installed my system about 4 years ago and to date have generated about 22.5 megawatt hours of electricity, which has saved about 19 tones of CO2 emissions. My system saves my about $1200 per year on my electrical bill and generates about 75% of my electrical needs. I have included a very good website that can both help you estimate the costs of a solar installation and can help you find an installer if you decide to go forward with your project. I also inclued the site where I bought my solar panels and inverter (the third link below). I can give you a bit of background about solar systems to help you get an idea of what to expect. Solar electric systems come it two types: grid-tied or battery backed. My system is grid-tied. That is the most popular type because it is much less expensive and requires less maintenance than the battery backed type. However, during a power outage the grid-tied system will go out too. So if you want continuous power you would have to have batteries. Most systems for home use run from 2 to 4 kilowatts in size, which is a measure of the peak power output of the system. That will provide between 50% and 75% of a typical home. A system in that size range will cost between $18,000 and $36,000 to install. Depending upon incentives offered by your state or local government or utility you can expect to receive tax breaks or rebates of between about $2000 and as much as $15,000 leaving you with a net out-of-pocket cost of between $10,000 and $30,000. The website below has a very nice estimating program that will recommend a system sized for your needs and can calculate all the tax and rebates available to you based on your zip code. You will need to give it how much electricity your home uses. Look at your last 12 months of utility bills to calculate that. The program also calculates your monthly, annual and lifetime savings as well as the break-even time for you system. It also estimates the increase in property value that a solar system will provide you with. I think you will be very pleasantly surprised to learn how fast a system can pay for itself. Including the added property value most systems will reach break-even in less than two years. See the second link, which is directly to the "My Solar Estimator " page. It is very easy to use. Before you select your system's final size you should consider replacing some of your appliances. This is especially true if they are the age of your home. Newer appliances are much more energy efficient. You can reduce your solar system size by purchasing a couple of thousand dollars worth of energy star appliances first. That will actually make your total system cost, including new appliances less - plus you get new appliances - nice! Appliances to focus on are: electric stoves, dryers or ovens, consider replacing with gas; refrigerator, washing machine and dishwasher, consider replacing with a new energy star rated unit. If you have electric central heating consider replacing that with a heat pump or gas furnace. The solar estimating program can help you evaluate the economics of these changes. Also do not forget to replace all incandescent light bulbs that you can with compact fluorescent units - do that this weekend ;). Note also that the My Solar Estimating program will calculate the cost of financing a solar installation. Most people finance the installation by refinancing their mortgage and the program will tell you how much additional your monthly mortgage will be to finance the system. The Find Solar site is one of the best places to locate local reputable solar installers once you are ready to pursue the installation. Another very good source of general information about solar and other renewable energy options for homeowners is Home Power Magazine (third website). Good luck with your new system.

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