Photovoltaics (PV) is a technology that converts sun light into electricity. Photovoltaics refer to the unbiased operating mode of a photodiode in which current through the device is entirely due to the transduced light energy. Photovoltaics is most commonly known as a method for generating solar power by using solar cells packaged in Photovoltaic modules. Generally these individual cells are electrically connected in multiples as solar arrays to convert energy from the sun into electrical energy. Solar cells are made up of a variety of materials which have the ability to absorb photons of light from the sun thus increasing their electronic energy level and creating electricity. Today, these materials include: Crystalline Silicon, Cadmium Telluride (CdTe), Copper Indium Gallium Selenium (CIGS), amorphous Silicone (Si) and continuous printing organic materials.  Due to the global need for energy and the inability of common sources of energy (oil and gas) to keep up with demand and because of negative trade-offs  for other sources such as coal and nuclear many new sources of energy are being explored. Solar energy has significant promise in that it does not emit any green house gasses, it is most efficient during the middle of the day when demand is highest and a solar cell can operate relatively maintenance free for well over 30 years. Solar cells are durable. One of the early applications were on satellites. The cost of solar cells is continually decreasing and the efficiency increasing.   Additionally, solar electric generation has the highest power density (global mean of 170W/M squared) among renewable energy.  There is an abundance of solar energy available. There are 89 petawatts of sunlight reaching the earth’s surface which is more than 6,000 times the 15 terawatts of average power consumed by humans. A 100 mile by 100 mile solar array located in southern Nevada for example could provide all the power needs to the United States.

 The key down sides to PV include the cost, ranging from $6.50 - $10.00 per watt depending on the application and the fact that when the sun is not shinning, very little to no electricity is generated. Therefore solar PV needs either a battery storage system or more commonly it is tied into an existing electrical grid.

 Incentives can help lower the cost of PV installations. (see our home page for details) The purpose of incentives is to grow the industry even where the cost of PV is significantly above grid parity to allow it to achieve the economies of scale needed to reach grid parity. The policies are implemented to promote national energy independence, high tech job creation and reduction of CO2 emissions. Three incentive mechanisms are used: Investment subsidies – refund part of the cost of installation of system, Feed-in Tariffs/Net metering – the utility buys PV electricity from the producer under a multiyear contract at a guaranteed rate, and renewable energy credits. Nearly all areas of the US have one or more of these incentives to encourage PV installations.

Building Integrated Photovoltaics (BIPV) is the term used when PV is incorporated into new domestic and industrial buildings as a principal or ancillary source of electrical power. Typically an array is incorporated into the roof or walls of a building and roof tiles. Arrays can also be retrofitted into existing buildings. In this case they are usually fitted on top of the existing roof structure.

The technology needed for the composition as well as the production of PV cells is rapidly changing.  The cost/performance ratio is continually improving such that the federal government has set a goal of being at grid parity (cost to produce electricity using Photovoltaic is equal to the cost for utilities to produce electricity from other sources such as coal and gas) by the year 2015. The Solar Energy Industries Association (SEIA) has released it's 2008 Solar Industry Year in review highlighting a third year of record growth. 1,265 MW of total Solar Power were installed raising the total US capacity to 8,775MW. Installed grid tied PV increased by more than 18,000 installations in 2008.

Now! With Incentives, companies can produce electricity at below grid costs and make money. We don't know how long these incentives will last, so it may is best to act now.