Knowledge
Solar energy is the energy of the future. The Sun has been active for billions of years. The Sun provides light and warmth; all this energy is given to humanity free of charge. In less than an hour, the Sun conveys to the Earth as much energy as humans consume in an entire year.
Comparison: One hour of sunrays falling on one square metre of surface on Earth provides as much energy as 6,300 liters of oil used for central heating.
If humans were to use 1 % of this enormous energy potential, the energy problems of our planet would be solved permanently. By using the energy of the Sun, mankind will be less dependant on conventional energy sources such as oil or gas; these are limited resources and in the past years their price has increased by 100%, not to mention the fact that these fuels are very damaging to the Environment.
Why solar energy?
Solar energy will help improve our climate. A PV plant with an achievement of ca. 3 kWp, saves the environment 800 kg of CO² per year – this is as much CO² as a car will emit after driving 10,000km. In Germany, we have approximately 50% of the irradiation of the Sahara. Does Germany have enough space for PV installations? Yes we certainly have! For example, in Germany, we have about 2,800 km² of roof area. In order to cover the entire demand for electricity of Germany, one requires approximately 3,000 km² of PV Modules.
There are also many other advantages to solar energy: PV plants leave behind no old loads. Every piece of used material can be resized and reused according to new technology.
Solar energy creates jobs. Presently the photovoltaic industry has created almost 20,000 jobs and this figure is increasing annually.
A PV plant offers interesting financial possibilities. In this field profits are not only generated for the businesses and the investors, but also for individuals who install a private plant for their own use. By using the energy of the Sun we will become independant from conventional resources such as coal, fuel and gas. No energy source is as clean as solar energy.
In Germany, the current production of energy from the Sun, namely PV, is becoming evermore popular, at the moment there are approximately 800,000 solar plants in operation. Such a significant number is due to an ever increasing environmental awareness, decreasing costs for the installation of private PV plants and also encouraging State legislation. Even with small assets, one can still make a profit, all this while helping the Environment. In some cases, there are also fiscal advantages; for more information regarding this topic you should consult with your tax adviser. We will provide you with a feasibility analysis of your plant.
General information
Photovoltaic: The principle is easy. In 1921 Albert Einstein did not receive the Nobel Prize for the theory of relativity, but rather for its interpretation of the photo electric effect. A genius stroke that after further advances is today known as photovoltaic (PV). This is the no. 1 in environmentally friendly energy production. Photovoltaic is the direct transformation of sunlight into electric current which is based on a physical reaction. The photovoltaic cells are placed together in rows to form photovoltaic panels, and in this way they fulfill their use.
Almost 95% of all photovoltaic cells have 50% silicon (not to be confused with silicone) in them, this is the second most abundant resource to be found in the crust of the earth. A photovoltaic cell consists of two layers: one negative and one positive conductor. When the sunlight falls onto the photovoltaic cell, a physical reaction takes place, releasing a direct current. Since most electric devices work exactly like the electricity network with alternating current, a transformation from direct to alternating current is necessary. An inverter acheives this process. The electricity produced can now be used in households, stored in batteries or fed into the grid.
In Germany, we have approximately 50% of the insolation (sun radiation) of the Sahara. Therefore, we recieve 1,000kW of Solar energy per square metre per annum. The South of Germany only gets ten percent more Sun exposure than the North. Nevertheless, in Hamburg there are on average more sun hours than at the Bavarian Tegernsee and the island of Usedom in the Baltic Sea is the sunniest place in Germany.
Now let’s go on the roof
For a PV plant on a roof to be permanently profitable there must be at least 10X10m of usable space. During peak sunshine, a 10 square metre PV plant in Central Europe produces an average of 1kW of energy. This figure can be higher depending on the type of module.
Output
Achievement of the optimal output depends on the inclination and the allignment of the panel to the Sun. A better performance of the plant can be ensured if the panels are installed facing South and at an angle of between 25 and 25 degrees. The panel is most efficient is it is installed facing South and inclined by between 25 degrees and 45 degrees. A deviation towards East or West by up to 50 degrees will decrease the energy output by around 8%.