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Installing a solar electric photovoltaic (PV) system on your home provides you with a clean, renewable source of power that will pay for itself after a period of time, and then continue to save you money by providing some – if not all – of your electricity needs.

Before deciding to go solar, you may want to consider some of the variables associated with installing a solar system on your home. Once you decide to investigate solar, it’s important to ask the proper questions when obtaining a quote for your solar system. Silicon Valley Power recommends the following:

    • Determine how much electricity you are using by checking your electricity bill for the past year. Electricity is billed per kilowatt-hour (kWh). Some customers average under 500 kWh per month, while others may use over 1,500 kWh a month. A 12-month total will be most helpful, as your usage will vary from season to season. 
    • If you have partial shade, or shade at certain times of the day, on your roof where you wish to put your solar array, the amount of power that can be generated throughout the year will be less than is generated by solar panels that are in continuous sunlight. This should be considered during the economic analysis. 
    • The direction your system faces makes a difference in performance. Solar panels facing south are considered ideal for generating power. Arrays facing west and east are less ideal, and panels should never face north. Performance may be lowered by a split system facing multiple directions. 
    • Your roof needs to be in good condition to hold the solar installation. Most solar installations have a lifetime of 20-30 years. If your roof is due for replacement in the next few years, you should consider replacing it before you install a solar system to avoid the cost of removing and reinstalling the system later when you replace the roof.
    • There are a number of experienced installation companies. SVP does not make recommendations, but a list of companies that install home solar arrays in the area is available at http://www.findsolar.com.
    • Prices vary considerably between installers. As with any major home improvement, solicit multiple bids; SVP recommends at least three. Although your bids may reflect special circumstances, the average total cost of systems installed in 2010 was about $7-8 per watt before rebates. 
    • Be sure your installer is a licensed solar contractor and provides you with references. Contractor licenses can be verified at http://www.cslb.ca.gov
    • If you are thinking of expanding your home, adding a pool or buying an electric car, your future electricity requirements may grow. Consult with your installer about the prospect of expanding your PV system later if necessary.

Costs and Quotes

Solar installation company representatives will be able to give you an accurate estimate of how much sun your location will receive throughout the year, and how much energy can be generated by a system. Check multiple estimates and question any discrepancies you might find.

Because electricity rates for SVP customers are far lower than neighboring communities, be sure your installer knows: 

    • How much you pay for electricity (your “rate”) 
    • What rebate you will receive back from SVP (SVP’s rebates are usually higher than rebates in neighboring communities) 
    • What your estimated savings from federal tax credits might be
    • How long it will take for your system to repay you for the cost of installation. The equation is based on your usage, how large your system will be and how much power it will actually generate, how much it will cost to install, and what the projected savings will be.

Your quotes should include all expenses associated with the entire project. Quotes should be itemized and include: 

    • Performance of system: what will be the actual power generated for use in the home? This is determined by the size of the system, the direction(s) it faces, and how much sun it receives. 
    • Payback Estimate: at current incentive levels (SVP rebates and federal tax credits) and your savings on electricity costs, a payback period of between 5 and 8 years can be expected for an average system to repay your net out-of-pocket expense for installation.

Quality Assurance

Does the installer have references in the area that you can call?

    • Will the installer give you a reference to a customer who had a problem that was addressed by the installer?
    • The warranties must guarantee their work, their subcontractors’ work, as well as all the equipment provided for a minimum of 10 years in order to be eligible for SVP rebates.

More information on home solar installations is available at: http://www.GoSolarCalifornia.org.

Last updated: 11/15/2011 8:16:51 AM