What is it and how does it work?
Solar cells convert the energy in sunlight directly into direct current by use of the
so called photoelectric effect. Today the most common type of solar cell is the silicon
solar cell, it's manufactured from a thin slice of silicon, which is the same material
that is used in microelectronics.
When the sunlight hits the cell an electric current is created between the cells
front and back, which makes it possible to get a current of electrons if you connect
a wire between the metal connectors on the front and back. Sometimes solar cells, that
gives power, gets mixed up with solar collectors, that gives heat in the form of hot
air or water, but it's two different techniques to make use of the incoming clean energy
from the sun.
Many manufacturers guarantee a 25 years lifespan on solar cell modules. A sun power
project has also shown that this long lifespan is a reality in the Swedish climate.
Solar cells was used to power satellites as early as the 50's. The progress in the
semiconductor industry during this time also contributed to lowering the cost of solar
cells. Because of this during the 60's and 70's solar cells became a competitive
alternative also on earth, foremost when the distance to the electricity grid is
too big. After the energy crisis in the 70's extensive investment was made to develop
more efficient and cheaper solar cells for production of electricity.
Solar cells are already fairly common in countries with lots of sun and heavy need
of electricity, e.g. California and Japan. In Germany solar cells are also fairly common.
In Sweden solar cells were introduce to power lighthouses and emergency telephones in the
mountains in the late 70's and somewhat later as an alternative for holiday houses, boats, etc..
The big advantages with solar cells are among other things that they do not need any fuel,
they don't release any particles or carbon dioxide, they are silent and they last long, at
least 25 years. If we could store and transfer the electricity without any loss we would
with todays solar cells need to cover an area as big as half of Gotland to get the amount
of power used by the whole of Sweden.
The effective production of power from solar cells in Sweden is 600-900 kWh for each
installed kW and year, depending on where and how the system is assembled. In the spring
of 2005 there were close to 4 MW of installed solar cell effect in Sweden. If all of the
150 Mkr that has been reserved for the support (see below) of installing solar cells on
public buildings is used, this effect will increase with 4 MW and the total installed effect
will thus be double in three and a half years time.
Our partner for solar cells