We all know that the sun’s energy creates heat and light, but it can also be converted to make electricity, and lots of it. One technology that converts sunlight to electricity is called Photovoltaics or PV for short. You have probably seen PV panels around for years, but recent advancements have greatly improved their efficiency and electrical output. Enough energy from the sun hits the earth every hour to power our planet for an entire year.
How does Solar PV work?
Sunlight is made up of tiny packets of energy called photons. These photons radiate out from the sun, and about 93 million miles later, they collide with the semi-conductor on the solar panel here on earth. All of this happens at the speed of light. These panels are made up of several individual cells, each with a positive and a negative layer, which create an electric field. It works something like a battery. The photons strike the cell and their energy frees up some electrons in the semi-conductor material. The electrons create an electric current, which is harnessed to the wires connected to the positive and negative sides of the cell. The electricity that was created is multiplied by the number of cells in each panel and the number of panels in each solar array. Combined, a solar array can make a lot of electricity for your home or business. Notably, Solar PV is an incredibly reliable system, as PV cells were originally developed for use in space, where repair is extremely expensive, if not impossible. PV still powers nearly every satellite circling the earth because it operates reliably for long periods of time with virtually no maintenance.
Advantages of Solar PV
In recent years solar energy has also been an effective economic development driver. The U.S. solar PV market increased by 57 % in 2007, to 220 MW (Solarbuzz). In 2006, the cumulative installed PV power in the U.S. was 624 MW (IEA Photovoltaic Power Systems Programme). The Energy Information Administration forecasts the long-term growth of PV in the U.S. to reach nearly 3,000 MW by 2030, not including off-grid installations. The PV industry generated over $17 billion in global revenues in 2007 and worldwide PV installations increased to 2,826 MW in 2007, up from 1,744 MW installed during 2006 (Solarbuzz). Global cumulative PV capacity in 2006 reached 6,634 MW (EPIA).
Solar PV technology continues to grow and advance because it offers major financial and environmental advantages. Solar PV technology produces clean energy, it has no emissions, no moving parts, it does not make any noise, it is visually unobtrusive, and it does not even need water or fossil fuels to produce power. Moreover, solar energy is a locally available renewable resource. It does not need to be imported from other regions of the country, or across the world. This reduces environmental impacts associated with transportation and also decreases US dependence on imported oil. Unlike with other fuels that need to be mined or harvested, using solar energy to produce electricity does not deplete or alter the original resource.
Consider these statistics: installing a typical 10Kw Solar PV system is the same as:
1. Planting more than one acre of trees per year.
2. Driving a car 10,000 miles less per year.
3. Burning 50 barrels of oil less per year.
4. Emitting 5 tons of Carbon Dioxide less per year.
5. Emitting 40 tons of Sulfur Dioxide less per year.
The beauty is that a Solar PV system it can be located right where the power is needed, in the middle of nowhere, or it can be tied into the power grid. Moreover, a solar PV system can be constructed to any size based on energy requirements. The owner of a solar PV system can enlarge or move it in case his energy needs change. It is possible for homeowners to add modules every few years in the event their energy usage and financial resources grow.
Government support for Solar PV
One major drawback particularly to consumers is that currently Solar energy is more expensive to produce than conventional sources of energy due to the cost of manufacturing PV devices, as well as because of the conversion efficiencies of the equipment. However, as the conversion efficiencies continue to increase and the manufacturing costs continue go down, solar PV will become increasingly cost competitive with conventional fuels. As a way to help offset those upfront costs for consumers interested in installing solar PV systems, many states are providing incentives to residential, industrial and commercial customers of PV through tax credits, grants, loans, rebates, and exemption from local property taxes. Other industry support mechanisms, such as installer training and certification programs are also available. Overall solar PV technology is growing fast and it can play a big role in America’s clean energy economy anywhere the sun shines.