Renewable Resources – Photovoltaic Systems
We Should All Be Using
Renewable energy sources have numerous advantages. The main advantage is the absence of pollution, making them environmentally-friendly energy sources, a fundamental requirement for sustainable development of the planet. Also of note is their distribution around the entire world, which contributes to avoid countries depending on others for their energy supplies. Since they do not consume raw materials to produce energy, the running costs of renewable energy systems are much lower that is the case for conventional energy sources, and they are not exposed to variations in the price of oil or other raw materials. From a social point of view, renewable energy sources favour local development, since they generate a distributed economic activity located in the places where the energy is converted, being particularly useful for electrification of rural areas and as energy sources for other activities in off-grid locations.
What is Photovoltaic?
A Photovoltaic (PV) system converts solar radiation into direct current electricity. The power generators of the system are the photovoltaic modules made up of solar cells produced mainly by monocrystalline and polycrystalline silicon. Cells, transform solar energy into electricity. The current produced by the cells is converted into alternating current with a frequency of 50 hertz. This energy conversion is performed by the inverter. To allow for a good performance and optimum yields the entire PV system must be carefully designed and the system correctly positioned.
Grid Connected System
A grid Connected System is connected to the utility grid and feeds power generated back into the grid. The system consists of PV panels connected to the inverter. The power produced by the PV system can be either supplied to loads or fed back into grid when the PV system ‘Output’ is greater than the load demand. When the PV system output is less than the load demand (e.g. at night), energy will be consumed from the utility grid. Solar grid connected systems vary in size according to the space availability, power required to be generated and available funds.
Stand Alone Systems
Stand-alone Solar Power Systems or Stand-alone PV Systems operate independently of the electric utility grid (off-grid) and most often are used in remote areas where the utility grid is not available or where the connection fees of the grid are higher than the cost of an alternative energy system. Stand-alone Solar Power Systems are used to power remote homes, schools or villages. The generated DC power needs to be stored in battery banks and converted to AC power for supplying to AC loads through the inverter.
