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Electricity generated by solar panels is referred to as PHOTOVOLTAIC energy. This tongue twisting word is often shortened to "PV," and thus we refer to a solar system that generates electricity as a PV system. Q. What is a PV system? A. PV technology produces electricity directly from electrons freed by the interaction of sunlight with a solar panel made of semiconductor material. The power provided is direct current (DC) electricity. The basic building block is known as a cell. Many cells put together are known as a module, and many modules assembled together form an array. A PV system will consist of an array of modules generating DC electricity, an inverter, and sometimes battery storage back up with charge controller.
A. There are two kinds of electricity, DC and AC. Homes that are connected to utility power use AC electricity. Flashlights, small radios and automobiles use DC electricity. In order for you to be able to use solar to operate the appliances in your home, an inverter will convert PV power from DC to AC. Inverters can be further classified as units that use batteries (UPS) and those that use the utility grid as power storage (Grid-tied). Inverters are now required to possess meters that will indicate their performance and some manufacturer's supply remote display units that can be mounted inside the home. It is important to check on your inverter regularly to become acquainted with its operation and performance.
A. The amount of power produced will depend upon how large the system is. In California the average residential customer purchases 6,500 kilowatt-hours (kWh) per year. There is enough sunshine falling upon on the average home to produce this and a system can be designed to offset all electrical needs. The cost to accomplish a 100% system may be prohibitive and sometimes it makes more sense to simply reduce or 'shave' your consumption. Some utilities use tiered rates when they charge for consumption which means that the more energy you use the higher is the cost per kilo-watt-hour. The most economically feasible size is usually between 50% and 75% of your annual household needs.
A. A solar system using batteries for storage can "ride-out" utility blackouts. Batteries add significantly to the expense of a system while providing no payback, need weekly maintenance, are hazardous and will need replacing every five to ten years. For this reason most city dwellers are opting for a "grid-tie" system.
A. Today in California you may connect your solar system directly into the wires of your utility. Since the "Net Metering Law" allows you to do this you will actually be spinning your meter backwards when your system is generating more power than you are consuming. Thus you can 'sell' electricity back to the utility, up to the amount you would have used. Without Net Metering you would be forced to 'sell' the energy back to the utility at a lower or wholesale rate and buy it back at a much higher retail rate. Net Metering is one of the principle reasons solar electricity has become economically viable Q. Just how big is a typical system? A. Solar PV systems range in size from fifty to four hundred square feet. A system composed of high efficiency cells will produce 1kW per hour for every 100 square feet. In order to qualify for the California Energy Commission's (CEC) "Buy-Down" rebate, the maximum size cannot be more than 200% of the home's annual historical needs. Q. What is the California Energy Commission (CSI) Rebate Program A.The State of California will help you buy a solar electric system. The California Public Utilities Commission will pay you a lump sum rebate up front or monthly for five years based upon the actual performance of the system. The amount of the lump sum rebate is calculated by using an online tool (http://www.csi-epbb.com/) created to take into account module and inverter efficiencies, tilt and orientation, shading and local weather to produce an Expected Performance Based Buydown (EPBB). The rebate was administered by the California Energy Commission (it was called the Emerging Renewables Program-ERP) but the program was extended and altered on January 1, 2007 (it is now called the California Solar Initiative-CSI). In prior years the rebate had been as high as $4.50 a watt but has been reduced to $2.50 in 2007 and is scheduled to be reduced again, soon. You must be serviced by SCE, PG&E or SDG&E utilities to qualify for the state rebate. Q. How can I get information on the State's Rebate program? A. You may apply for the program yourself by going to their website, http://www.gosolarcalifornia.ca.gov . We can also provide the forms and do the necessary paperwork to make your reservation. Q. Is there a program for residents of the City of Los Angeles? A. The LADWP has a similar program for its customers. Information on this very successful program can be found on the web at http://www.ladwp.com/ladwp/cms/ladwp004171.jsp . We can prepare all of the forms and make the necessary submittals. LADWP is funding systems with a rebate starting at $4.50 per watt as a lump sum payment and uses an online calculator ( http://rredc.nrel.gov/solar/codes_algs/PVWATTS/) to assess its value using performance related variables (tilt, shading etc.) Q. How much does a PV system cost? A. As systems get larger, the cost per watt is lower. A two (2) kilowatt system may cost between $16,000 and $20,000 ($8.00 to $10.00 per watt), while a five (5) kilowatt system may be installed for as little as $35,000 ($ 7.00/watt). All of these prices are figured before the rebates or tax credits. The final cost may be as low as $2.50 per watt (or $12,500 for a 5 kW system). Q. Are there tax credits or any other incentives to go solar? A. There is currently a federal tax credit of 30% with a maximum of $2000 for any residential solar system. There is no cap on the tax credit for solar when it is used in a business application. This tax credit is slated to expire at the end of 2008. The Federal (MACRS) and State accelerated depreciation deductions can also significantly reduce the final cost of a system used for commercial applications. Q. Will my property taxes go up if I install a solar energy system? A. In California your home value may not be re-appraised by the County Assessor's Office for solar related property improvements, currently. Q. Are there any other incentives or programs available to help me afford a solar energy system? A. It depends upon where you live. Some municipally owned utilities have established their own programs and some credit unions and banks have special loan rates. For a comprehensive list of incentives, rules and regulations affecting solar energy go to http://www.dsireusa.org/index.cfm?EE=0&RE=1. Q. Why is
there such a variation in prices?
Q. How long does it take for a PV system to pay for itself? A. It is more instructive to think of solar as an investment that yields an annual return, much as a bank savings account provides interest. A solar PV system will generate savings that would equal 7% to 15% per year at today's electric rates. This savings is not taxed as is interest from a bank account. Thus you would have to find a bank account yielding 14% to 28% to equal the return on a solar electric system. The fact is, if you want electricity you will be paying somebody. You may prefer to pay the utility bill forever, or you may choose to become your own utility with solar PV, instead. For more information on payback, please go to our page "The Economics of Renewable Energy."
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