• What is a PV array?

• Are solar electric systems safe?

• What is PV conversion efficiency?

• What Happens If the Sun Doesn't Shine?

• Are solar energy systems becoming cheaper?

• Isn’t Solar Electricity Expensive?

• I Already Have Utility Power — So Why Should I Choose Solar Electricity?

• What Is a Grid-Tied Solar Electric System?

• How Do Line-Tied Solar Electric Systems Work?

• Can I Use a Line-tied Solar Electric System as a Back-up Source During a Utility Power Outage?

• Does My System Have to Include Batteries?

• How can I find about the financial incentives and rebates in my state?

• Are Tax Credits Available?

• Can I Sell Excess Solar Electricity Back to My Utility?

• How Do I Know What Size System I Need?

• Who is doing research on solar energy?

• How can I estimate my ROE of a solar project?

• What is a PV array?

  A PV array is an interconnected system of PV modules that function as a single electricity-producing unit. The modules are assembled as a discrete structure, with common support or mounting. In smaller systems, an array can consist of a single module.

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• Are solar electric systems safe?

  Yes. Solar cells are mostly silicon, the primary component of sand. There is no exhaust and no toxic materials to leak out of the system. The electricity coming through the inverter is just like the electricity coming from household wall sockets; you should use the same care you would with utility power. All components are approved for utility interconnection and are installed according to standard construction practices.
  

   

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• What is PV conversion efficiency?

  It is the ratio of the electric power produced by a PV device to the power of the sunlight shining on the device.

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• What Happens If the Sun Doesn't Shine?

  Receiving and using electricity is depended on the storage system for a stand-alone PV system. The following are factors to consider for an off-grid system:

  - Days of autonomy
  - Battery capacity
  - Rate and depth of discharge
  - Life expectancy
  - Environmental conditions
  - Price and warranty
  - Maintenance schedule

  For a grid tied system, your line-tied solar electric system will continue to produce electricity during cloudy weather at a slower rate. At night or during inclement weather, additional electricity is provided to your home through your utility connection.

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• Are solar energy systems becoming cheaper?

  Solar panels are still quite costly when compared to conventional electricity. This is because the production of solar panels requires high tech equipment, still is labor intensive and requires special materials. However, every solar panel purchased makes the next one cheaper, in stark contrast to nonrenewable sources, which become scarcer and more expensive with every ton that is burned. The price has gradually been coming down in recent years because of market growth, improved materials and production processes.

   

  

   (Courtesy of Solar Energy Industries Association, SEIA)

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• Isn’t Solar Electricity Expensive?

  No. The cost of solar technology has dropped dramatically in the past 10 years and thanks to many state rebates, income tax credits and net metering, a solar electric system may be your most cost-effective power solution. With current cash incentives, a typical California family, can expect to spend about $12,000 on a solar electric system that meets at least half of their household electricity needs.

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• I Already Have Utility Power — So Why Should I Choose Solar Electricity?

  Solar electric systems allow you to lock in your electric rates at today’s prices. With fossil fuels likely to become more expensive in the future, purchasing a solar electric system today is a smart economic move. Solar electric systems also offer greater self-sufficiency, reduce dependence on imported oil and are far better for the environment than power from conventional power plants. Altair Energy’s line-tied solar electric systems make it easy and affordable to produce electricity right at your home.

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• What Is a Grid-Tied Solar Electric System?

  “Line-tied” means that your system is connected to the utility lines or the “grid”. A line-tied solar electric system is designed to meet all or a portion of your daily energy needs. This connection enables you to obtain the balance of your electricity from your local utility; it also allows you to send excess solar electricity back to your power company for use later.

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• How Do Line-Tied Solar Electric Systems Work?

  Line-tied solar electric systems use photovoltaic (PV) technology to convert sunlight into electricity during daylight hours. If your home or office requires more electricity than can be provided by your system, the balance is provided through your utility connection.

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• Can I Use a Line-tied Solar Electric System as a Back-up Source During a Utility Power Outage?

  A line-tied solar electric system will continue to provide electricity to your home during an outage if it has a bimodal inverter and batteries. Aten Solar solar electric battery back-up systems (SunSystemsPLUS) are specially designed to provide power to such critical loads as refrigerators, furnace fans, lights, security systems and computers. In the case of a power outage, the SunSystemPlus will instantaneously provide power to your critical loads.

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• Does My System Have to Include Batteries?

  No. Batteries are only essential if you want ‘back-up’ power in the case of a utility outage. Otherwise, your Line-tied PV system will send any excess generated electricity back to the utility, using the utility grid (rather than batteries) as the storage medium.

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• How can I find about the financial incentives and rebates in my state?

  Many states now allow for the exclusion of a solar electric system from property taxation as long as the property does not change ownership. In other words, while the value of your house will go up with the installation of a solar electric system, this addition can be excluded from your property’s assessed value. For the latest information pertaining to rebates and incentives in your state, visit www.dsireusa.org .

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• Are Tax Credits Available?

  Yes. Over 25 states now offer a personal income tax credit for the installation of a solar electric system. In California, a one-time tax credit is available to home owners who install a solar electric system by January 1, 2006. For tax years 2004 through 2005 purchasers can take a 7.5% tax credit. New York state offers homeowners a 25% personal income tax credit (or up to $3,750) of the cost of equipment and installation of a PV system. In Arizona, a Personal Income Tax Credit in the amount of 25%, (up to a $1,000) is available to individuals buying a PV system. the credit drops to 7.5% during 2004 and 2005. For the latest information pertaining to your state, visit www.dsireusa.org.

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• Can I Sell Excess Solar Electricity Back to My Utility?

  Electric utilities in California and many other states now give retail credit to solar customers who feed excess solar electricity back to the power grid. Known as “net metering,” this utility policy is implemented by letting your electric meter spin backwards when you feed excess electricity into the grid.

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• How Do I Know What Size System I Need?

  The best indicator for sizing a solar electric system is your historical electrical usage, or the number of kilowatt hours (kWh) you consume each month. It is especially important to determine an annual average of your kWh usage, because many families experience seasonal spikes in usage. This average gives you a starting point for comparing the energy output of various systems. Contact your local utility to request an annual summary of your monthly electric usage.

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• Who is doing research on solar energy?

  http://www.nrel.gov/ncpv/documents/seb/seb8.html
  http://www.nrel.gov/ncpv/documents/seb/seb9.html
  http://www.nrel.gov/ncpv/documents/seb/seb10.html
  http://www.nrel.gov/ncpv/documents/seb/seb11.html
  http://www.nrel.gov/ncpv/documents/seb/seb12.html  

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• How can I estimate my ROE of a solar project?

  There is a few financial calculators offered free of charge on the web. They are as follows:

   

  www.consumerenergycenter.org/renewables/estimator/index.html

  http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/

  http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version2/

  www.findsolar.com?new_sess=1

  http://solar.coolerplanet.com/

  www.retscreen.net/

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    Solar and wind intensity global chart

   For detailed information, please visit:
http://www.bergey.com/wind_maps.htm