Solar Energy Technologies. There are two ways to achieve Solar Energy Harvesting. "Solar thermal technology" refers to the heating of water which then circulates through a closed looped system. This can then be used for water or space heating. "Photovoltaic (PV) technology" represents the harvesting of the Sun’s energy through panels. The panels directly convert solar energy into electricity. Solar insolation, the amount of solar energy that can be harvested at a given location, is essential information in using both of these technologies. Check solar insolation at your location…

How Solar thermal works. Heat from Sun can be converted into the heated water through the solar collectors, which are usually located on the roof facing the Sun. The solar collector is filled with a system of branches that forms one closed loop. Branches are filled with water that absorbs solar heat through the collector. Using pumps, hot water is then circulated through the closed loop system. The pumps force hot water circulation creating a more efficient solar thermal system.

Working principle of photovoltaic (PV) system. Solar panels consist of numerous solar cells connected to generate electricity. Solar cells have a capacity of producing 12V or 24V output from the panel terminals. When exposed to the sun, solar cells convert solar energy into direct current (DC) electricity. Solar panels are made of silicon in a two different ways: monocrystalline solar cells (made of one crystal layer) and multicrystalline solar cells (made of combination of crystal layers). In past two-three years, another technology of creating solar cells has made its way to the market - thin film solar panels.

Clean Energy. Because the electrical energy obtained from the sun does not create pollution and does not produce greenhouse gases or toxic waste, this source is clean and renewable. Solar energy is sustainable and reliable for our long-term future.

Choosing the right PV panel. Stand Alone and Grid Tied Solar Systems. Because solar PV panels generate DC electricity, for grid connected systems, inverter (converting electricity from DC to AC) is required. When panels are connected to the grid through inverter, (grid-tied system) all electricity produced in panels is transferred directly to the grid.

On the other hand, stand-alone systems, requires batteries in order to store generated electrical energy. Usually higher voltage level is required, and it is possible to increase it by connecting panels in series. Similarly, connecting panels in parallel will increase the output current of the solar system.

Choosing the proper system type that suits your needs can be challenging. First, decide if the system will be stand alone or connected to the grid. Stand alone systems are very good solutions for remote and rural areas. They provide electricity through solar panels during the day while simultaneously charging the systems batteries which become the electricity source during the night. If your home/business has access to the distribution network (grid), It is possible to connect a solar system to the grid and feed the grid (“Net-metering”). Net-metering is the ability to pump electricity back into the grid and be paid a retail rate for each kWh generated. In most of United States, electrical utility companies support a net-metering program. Obviously, regulations which differ from state to state.

Benefit of Solar Systems. The greatest benefit of solar systems is that they provide clean renewable energy out of the free sunlight. If used for heating, cooling, and/or ventilation technologies, solar thermal can offset a big portion of energy consumption. Used through PV panels, solar energy can generate enough electricity to cut utility bill by 20-50% depending on location. In addition, in an era of global warming, a solar system makes you carbon neutral. One may use these technologies for Carbon offsetting.