Environmental Engineering Reference
Figure 5.14 Photovoltaic systems on single-family homes. Foto: SunTechnics.
be sourced from other power plants. These power plants do not necessarily have to
be coal-driven, gas or nuclear plants. On the contrary, photovoltaic systems work
compatibly with other renewable energy plants, such as wind power, hydropower
and biomass plants.
An extra electricity meter is normally required to calculate the photovoltaic power.
This meter calculates the quantity of electric energy that has been fed into the
grid, which is then credited according to existing tariffs. If, as in Germany, the
feed-in tariff for solar energy is higher than the normal tariff for electricity, it can
make sense to feed all the electricity produced by a photovoltaic system into the
grid through a feed-in meter and then to buy back some of the supply at the lower
tariff. In other countries solar power is sometimes credited at a noticeably lower
rate than normal electricity. If this is the case, it makes more sense to use the
electricity generated through solar power fi rst and only feed excess supplies into
Connecting to the grid in Germany is usually not a problem. An electrician is needed
to connect the system and the relevant electricity supplier has to be notifi ed. In
addition to the connection protocol, technical documents relating to the photovoltaic
system are submitted with the application. It is important that the system complies
with the general regulations, and this is not generally a problem with current system
suppliers. In most cases, a representative of the electricity supplier inspects the
system. The reimbursement is handled automatically and is calculated according to
the meter reading. The electric company and the operator of the photovoltaic system
usually also sign a contract. However, this is not always a stipulation.