Future energy generation Structure and operation principle of a solar cell

PRINCIPAL OF A SOLAR CELL

Generally, solar cells are composed of two layers One of which is neg­atively charged and the other positively. If sunlight hits these layers, voltage is created between the two layers. The energy thus created is released electrically by means of an electric circuit and therefore utilised. Several solar cells are assembled to create solar modules.

STRUCTURE AND FUNCTION OF A SOLAR CELL

The solar module consists of individual solar cells which are connected electrically The solar module consists of individual solar cells which are connected electrically. The cells are enclosed in order to protect them against climatic and mechanical influences. There are a number of methods to enclose solar cells.A frequently-used method is enclosing them in EVA (Ethylene-Vinyl Acetate) With standard modules, the solar cells are enclosed between clear glass (front side) and a plastic foil (rear side) by means of EVA. In addition, the module is framed, e.g. the frame is made of alumi­nium or stainless steel (and includes a circular seal). The used glass has special properties: It is hardened, highly transparent and has a specially-treated surface in order to keep incident light reflections to a minimum.

For the correct construction of a guaranteed safe substructure, the Solarzentrum Allgäu offers the in-house developed VARIO roof hook in combination with the VARIO aluminium profile rail.

+ MORE ABOUT THE VARIO ROOF HOOK

PRINCIPLE OF USE OF SOLAR USE

The solar modules mounted on the roof use the sunlight to generate direct currentwhich is then converted into the supply voltage of 230V by means of inverters. The voltage generated at the output can then be fed into the national grid via an input meter. Alternatively, the energy can be stored in solar batteries (off-grid systems) or used directly.

In addition to conventional photovoltaic modules, we offer our in-house-developed and prize-winning (Bundespreis 2008) PV-Therm combined module. The thermal water circulation at the rear side ensures maxi­mum solar electricity outputs and allows for multiple applications in the area of heating support.

+ MORE ABOUT THE PV-THERM COMBINED MODULE

 

SOLARENERGY IN GERMANY

In Germany, the average solar irradiance amounts to 900–1200 kilowatt hours per square metre annually The highest insolation values are achieved in the sunny foothills of the Alps, in Bavaria and Baden-Württemberg. Moving northwards, the sun intensity decreases. With current state-of-art technology, this would be enough to make solar energy the cornerstone of German power supply.

RENEWABLE ENERGIES AS A CHANCE

The sun is a gigantic & almost inexhaustible power plant Year after year, it generates more than 219,000 trillion kilowatt hours of energy for free. That is 3,000 times more than the whole world population consumes in one day. With a life cycle of up to thirty years, a photovoltaic system generates 15–20 times more electricity than is used producing it. The same applies for commercially-available solar heat systems. The energy expenditure required for the production of solar collectors already pays for itself after 15 months; and they last up to 25 years. Generally, solar systems can generate emission-free electricity or heat for more than 20 years.

Renewable resources as new energy sources While today, approximately 15% of power consumption and 7% of the heat required are obtained from renewable resources, the federal government intends that more than the half of the primary energy consumption shall be obtained from renewable resources by the middle of the century.Since 2009, solar heat has been supported by the Erneuerbare-Wärme-Gesetz (Renewable Energy Heat Act) passed by the federal government. The Marktanreizprogramm (MAP; Renewable Energy Incentive Program), extended to EUR 500 million in 2009, is an important driver for the use of solar collectors in Germany.

Investing with public funding support Generally, photovoltaic systems are supported in accordance with the Renewable Energy Law; the latest assistance is available on our website. This form of assistance is guaranteed for 20 years! The EU, federal government, federal states, communities and power suppliers all support the launch of environmentally-friendly energy technologies by way of a wide range of promotional programmes. We will be happy to advise you about the different possibilities!

USING SOLAR ENERGY OPTIMALLY

A photovoltaic system is an electricity producer – i.e. your own small power plant on the roof It does not produce any harmful substances and, at the same time, is easy on the purse as the dependency on fossil raw materials and thus on expensive electricity decreases. Annually, the sun emits an energy quantity of approx. 1,000 kilowatts per square metre in Germany. This energy potential corresponds to approx. 100 litres of heating oil or 100 cubic metres of natural gas.

The correct roof pitch is the prerequisite for optimum use A south-oriented surface is ideal. However, a deviation to southwest/southeast only decreases the energy yield slightly. In contrast, shade must be avoided or excluded with PV systems. Due to shade, individual modules can generate no or only a low level of electricity, which could affect the system's overall performance considerably. The easiest way to find out the roof pitch is examining the construction plans. Alternatively, the inclinometer can be used. If you are interested, we would be happy to advise you accordingly.