Deciding if Solar is Right for Your Home

What is the first step I should take when looking into solar?

Reducing your electricity use will have the quickest and most positive impact on the environment and on your pocketbook. Start with your electricity usage. Pull out your electricity bills. What has your kWh usage been each of the last twelve months? How much are you paying for electricity? What rate plan are you on? The objective is to understand how much electricity you use, what you are using it for and when you are using it. This information is critical to conservation, energy efficiency efforts and to proper sizing of a solar electric system. Armed with this information do an energy efficiency audit.

PG&E offers free energy audits to its customers online at http://www.pge.com/res/energy_tools_resources/energy_tools.html. Print out the audit results, if you do decide to go solar, a copy of the audit will need to be submitted with your solar rebate application.

Why does it matter when I use most of my energy?

A solar electric system that is tied to the electrical grid feeds electricity into the grid when the system generates more electricity than you use. You receive a credit for the electricity that you feed to the grid. You can then draw on electricity from the grid using the credits. Your electrical use is calculated over a twelve month true up period. This is called “net metering”.

PG&E offers several Time of Use (TOU) rates for which it charges more for electricity during peak hours occurring weekday afternoons, and less for electricity during off peak hours. TOU metering often works well with solar electric systems. These systems generate electricity during peak times crediting the homeowners account at the higher rates. If the homeowner uses most of her electricity during off peak hours, she then draws against those credits at the lower rates, allowing her to use more electricity than her system generated because she is using it at times when the rates are cheaper. If you are home and using power during the afternoon, investigate different rate schedules.

A solar contractor can help you determine which rate schedule is best for your electricity usage patterns.

Is my home a good place for a solar electric system?

Shading, roof orientation, the amount of space on a roof and the quality of the roof are all factors which need to be considered. You want to install a solar electric system in a location which is free from shading, ideally on a roof which is oriented south or west. Shading, roof orientation and the angle of the solar electric system will affect the amount of electricity your system produces, and are factors considered in calculating your state rebate. Shading is a significant factor. A fairly small amount of shade on one panel can greatly affect the production of each panel that the shaded panel is electrically connected with (similar to how a kink in a hose slows down the flow through the rest of the hose). Ideally, you should have unobstructed sun from at least 9am-3pm. Make sure your roof is in good condition, solar panels have performance warranties for twenty-five years and systems can last much longer. You don’t want to have to take the system down to fix the roof. Oftentimes, you’ll want to reroof at the time you put a solar system up.

A solar installer will come out to your home to do a site analysis and will take each of these factors into consideration when providing you with a proposal of a system size, the system’s estimated performance and installation cost.

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