What is PV Energy?
1.Introduction
The earth receives a huge amount of energy in the form of solar radiation: On average, 1700 kWh per square meter are provided every year by the sun. The total amount which is received on the planet’s surface is equal to approximately 10.000 times the global energy consumption.
Photovoltaics can convert this natural energy directly into electrical power: When a semiconductor material is illuminated by photons, an electrical flow is generated. As long as there is light, this solar cell will provide a direct current (DC) of electrical power, which can be converted into the standard 220 V alternating current.
The physical performance of a solar cell is measured in terms of its conversion efficiency. Currently, commercially available solar cells achieve efficiencies of approximately 15 %. Economically, the price of solar electricity as cost per kilowatt-hour is the most important benchmark. It is expected, that the costs of photovoltaic energy will further decrease and reach grid-parity (competitiveness with peak power prices) between 2015 and 2020 (depending upon location and irradiation).
2.Advantages of Photovoltaics:
As a form of energy supply, Photovoltaics offer a broad range of advantages:
- Fuel source is essentially infinite.
- PV produces energy without emissions (e.g. Greenhouse Gases)
- PV is a reliable Technology (no moving parts, module lifetime >25 years)
- PV is scalable, modular and flexible: It can be installed in almost every size and in every place.
- The materials of PV-Modules and Cells can be recycled.
- Photovoltaic Energy is sustainable, even in the strict meaning: The energy-pay-back of a module is between 1,5 and 3 years. After this period, the module has produced more energy than had been used for its production.
3.Market Situation:
Over the last few years, the PV Industry has experienced a strong growth, which is expected to continue. In 2007, the global cumulative installed capacity amounted to approx. 9 GWp. In an optimistic scenario, in the year 2012, a worldwide installed capacity of 44 GWp could be achieved, which would be equivalent to 44 nuclear reactors (Source: EPIA).