Solar energy is arguably the most reliable and cleanest form of renewable energy available to the common person. Additionally it is a never ending source of energy. While fossil fuels can theoretically run dry one time or the other, solar energy will be available in abundance till the day the earth exists. Given this scenario – affordability is not to be excluded – it is no wonder that countries and individuals are switching to solar energy over other forms of power.
What then are the components that make up a total solar energy unit?
Solar panels on the roof
The first component of solar systems is the solar panels which are placed on the roof where there will not be any shade or shadow, especially during the peak sunlight hours of 9am to 3pm. Generally a south facing orientation is preferred but that depends in inclination the panels are being installed. Any shading will disrupt production of power. Its importance can be gauged from the fact that even if one of the 36 cells in a solar panel goes below a shade, power production will be halved. The latest solar panels have systems that move and track the progress of the sun across the sky throughout the day.
Solar panels are also called modules. These contain photovoltaic cells made of silicon and transform the sunlight not into heat but into electricity. These cells have a positive and negative film, made of silicon which is placed under a thin slice of glass. The sunlight that falls on the cells has photons which displace the electrons from the silicon. These free negatively charged electrons move to one side of the silicon cell, thereby creating an electric voltage. It can be collected and stored in an electric box known as a fused array combiner. This box contains fuses and connections that transfer this electricity to an inverter. The current at this stage is DC (Direct Current) and must be converted to AC (Alternating Current) if it has to be used in your home or office. Any unit has a large number of solar panels that are connected to each other by wiring and forms a solar photovoltaic array.
The inverter steps up the DC power generated by the solar panels to AC 120/240 volt that can be used in the home or office. The inverter is connected directly to a dedicated circuit breaker in the main electric panel. The inverter is usually installed as close to the solar panels as possible and also in close proximity to the electrical main or sub panels of the home. Since the inverter makes a humming noise, it is usually fixed to external walls. If your solar energy system produces more power than you immediately consume, your electric utility meter will turn backwards!
In a solar electricity system that is linked to the utility grid, the DC power is converted to usable 120/240 AC power that goes directly into the electricity distribution network of the building. This is “net-metered”, that is the demand for power from the general utility grid is reduced when the solar panels are generating power. This leads to a lowering of energy bills.
While it is true that solar energy generating systems do not come cheap, the initial investment is quickly recouped through lower electricity bills. This is apart from ensuring a clean and green environment and reducing pollution levels.