Electricity can be produced directly
from sunlight by the Photovoltaic effect. Crystals of silicon semi-conductors
when subjected to light cause electrons to move and produce a voltage (DC).
The PV cells are connected together to form a module (solar panel) and
modules linked to form an array which can be roof mounted.
There are no
moving parts and apart from cleaning dust etc. from the array there is
no maintenance. Panels are guaranteed to produce not less than 80% of
stated output after 20 years.
How much power can a PV system produce?
Systems are usually between 1 and 5kW and can meet
between 25% and 100% of a households needs. A typical household will
consume around 3-4000kWh annually.
Approximately each kWp installed costs
50% of the cost is met by the Solar Grant scheme (see
link on previous
"sun" page for information).
Unless your household's electricity
consumption is very high it is likely that at midday in bright sun the
PV system will be generating more electricity than is being consumed by
your electrical appliances.
In this case export of electricity to a supplier arrangement
(i.e Grid Connect) would be an advantage and highly recommended.
Solar PV Installers list