solar energy

Using solar energy is nowadays usually means the energy that people themselves with their technology generation directly from solar radiation. This happens at the moment in the Netherlands and Belgium, mainly in two ways:

1.      The most common application is through solar panels with photovoltaic cells (PV-cells). That convert light directly into electricity: solar power.
2.     Another way to make use of sunlight is thermal solar energy at which sunlight is converted to heat. This is done by solar thermal (or solar collectors).

The term solar panels for both methods are used and therefore not entirely unambiguous.

 The major problem with the practical use of this energy is the solar constant, the (maximum) amount of energy per square meter per unit time on the surface, not very large. (about 1367 watts per square meter in the upper layers of the atmosphere, on the ground less, depending on the thickness of the intermediate layer of air, the angle at which the sun strikes the earth, the distance between Earth and the sun with the seasons change anything, and especially the occurrence of clouds.) Therefore the energy over a fairly large area 'harvested' in order to be economically viable. The word harvest is certainly applicable, since agriculture for centuries does nothing but solar energy harvesting biochemically bound form, such as starch in grains or potatoes.

 For countries where the sun shines almost all day is a good technology for solar energy harvesting: concentrated solar energy, also called solar thermal energy (in English: CSP: Concentrated Solar Power). Here the sun through mirrors together in a small area, where a high temperature occurs. With that high temperature steam is created, which as in a normal central electricity. In California, functioning since the 80s a number of CSP plants with a combined peak output of 350 MWe to full satisfaction.

Another form of renewable solar energy is the solar tower. Air is heated by solar collector under a circular translucent at the edge open. So is the translucent roof with a ground storage by the sun warmed air. In the center of the circle is a vertical tower, which is at the base has a large cross section. Because hot air is lighter than cold air, rises on the tower. The tower draws in more air to cold air and it is supplied to the new edge of the storage space. A continuous flow of air can be achieved by using water-filled pipes under the roof. Daytime heat it up and at night they give off heat. Thus, there is a constant flow caused by solar heat. The energy produced by the upward flow of air by wind turbines is converted into mechanical energy and generators, this mechanical energy into electrical energy.

 To illustrate the potential power of large-scale solar energy the following example. The energy consumption in Europe is approximately 1020Joule/jaar (over 3 x 1012 W). Based on an energy yield with a yield of about 15% would be an area in the Sahara with a surface of about 50,000 square kilometers net to satisfy all the energy used in Europe. See the orange area on the card in the Sahara. This exclusive space for roads, living and working in the area of ​​the solar plant. And if the problem of energy storage and transport is solved. For such a solar power station in southern Europe (eg Spain, see the illustration) would roughly double the area required. With obviously the same caveat regarding logistics and storage as mentioned above. Moreover, when northerly stations the difference between the seasons play a greater role.

 The purchase of solar panels requires a significant investment. For small systems (roof of a house), the prices for a complete system installed at approx € 3.50 per Watt peak power. On an average woningdak fits a 2 kilowatt peak, will cost € 7,000. In the Netherlands, every kilowatt-peak per year about 800-950 kWh (kilowatt hours). Considering rising energy prices and a constant yield deserves one system (without subsidies) on average within 12 years.

From 2009 to 2011 the Netherlands had a grant for solar energy (PV), the SDE. This was a compensation offered for each solar energy to electrical energy.

In Flanders, one in 800 families a solar energy installation in September 2007, which was ten times as much as three years earlier.

Many other countries in Europe have feed-in tariffs (feed-inn tarrifs) including Germany, Spain, Italy, France and Belgium. For every kWh generated is a fixed amount paid over a fixed period (15-20 years). These fees ranged from € 0.40 to € 0.50 per kWh in 2006 and between € 0.20 to € 0.30 per kWh in 2011. With the fees, the payback period is shortened and solar energy an attractive product for investors. Thus, a growing market created. The innovation thus generated, bring the cost of solar energy systems with 5-7% per year down. This is the point where they can compete with conventional electricity from the grid (for consumers now approximately € 0.23 per kWh) getting closer. Since 2004, the market is growing by an average of 50% per year. The prices of a panel fell from € 3,00 / WP in 2006 to less than € 0,60 / WP in 2012.

Another great advantage of solar panels is the fact that electrical energy can be obtained at places where it is difficult, or impossible, to electrical wires.

 Oil, gas and coal are actually derived forms of solar energy. They were formed from the remains of living creatures in the geological past, all supported by photosynthesis. The speed with which we currently consume these sources, however, by no means kept by the rate of photosynthesis by new organic fuels are created. Also, hydro-power is a form of solar energy: the water is evaporated by solar heat, by wind (also a result of temperature differences) transported upwards, falls as rain again on a mountain or height and the gravitational potential energy of the mass of the water as electricity again recovered at a lower level or fall - streams. Even wind power exists only by the grace of the solar heat generated by temperature differences. Only tidal power, geothermal energy and nuclear energy can not be traced back to solar energy, although nuclear energy uses heavy elements only in a supernova (explosion of a star in his last stage of life) could occur, but that was not 'our' Sun.