Sizing Your System: Part I

Sizing a photovoltaic system to meet all or a portion of your demand is quite easy actually. When considering such a system however, you need to ask yourself a few questions first.

Will a PV system make financial sense? Start by finding out what you're being charged by your utility per kilowatt hour. Take your total monthly charge and divide it by the total kilowatt hours used that month. The national average is 8-9 cents per kWHr. If this is in your range and your bills are small to moderate, installing solar will probably mean more out-of-pocket expense at this time. If you're a heavier user, start by cutting back on consumption if you haven't already. This means replacing old lightbulbs with fluorescent bulbs; getting Energy Star appliances; upgrading pool filters; installing better insulation and solar attic fans; and start switching off lights and computers when not in use.

In San Diego, the five-tiered billing system starts at 13.4 cents baseline and goes up to 20.1 cents per kWHr in the top tier. Such rates coupled with a rebate and tax credit for solar installations makes financial sense for many homeowners.

What incentives are there for solar installations? Go to the "Solar Incentives by State" link in this blog. A U.S. map will come up and then click on your state for a list of incentives for renewable energy. My previous blog (below) "Silver Lining to a Bad Energy Policy" details the upcoming federal incentives for solar.

Financial reasons aside, how does solar benefit the future of energy? One 2500-watt PV installation reduces greenhouse gas emissions by two tons per year by not using coal or natural gas-produced electricity. Contrary to what most people think, oil is used only in Hawaii for producing electricity but reducing use on fossil fuels is making sense both financially and environmentally. Solar-powered electricity also reduces the need for more nuclear power. Even as nuclear plants seem safer than ever, the problem remains on what to do with the waste.

Next week we'll actually size a system to meet your needs in your part of the country.