How Solar Energy works
The passive solar house
Building design must be taken into consideration to harness passive solar energy. Build up a passive solar house plan including design features allowing windows to capture maximum solar power input & reducing heat loss through walls and roof through effective insulation. A passive solar power system increases solar radiation capture and reduces heat loss, conversely, it is also used to retain coolness and maximise natural ventilation in hotter seasons and climes. All of these will reduce heating, lighting and air conditioning costs.
Thermal solar water heating
Thermal solar water, (or active solar), heating requires collectors to be placed strategically, usually on the roof or by a pool, to maximise solar power capture. The heat is collected in a liquid which is then circulated to the hot water storage tank. If the tank is well insulated the heat may be stored for a period of time. For pool heating the water is merely circulated continually through the collector.
Solar photovoltaic cells
Solar photovoltaics cells (PVs) use a semiconductor material, for instance, silicon. Other technologies include polycrystalline, monocrystalline and thin-film. Solar energy is absorbed by the semiconductor material and forms a reaction that allows electrons to flow freely, thus creating current - electricity.
Solar panels and solar roof tiles are made up of collections of PV cells, which may be fed into the building's electricity supply or the electricity grid.
Some form of electricity storage system such as a battery may be used to accumulate the energy allowing continued supply during cloud-cover or night time.
The efficiency of conversion from cells to energy is in the region of 10% - 15%, when the industry started it was a mere 4% and technology is improving all the time.
How Stuff Works has some useful articles on how solar photovoltaic cells work ; how to set up an outside light using solar energy; and how to calculate the number of photovoltaic cells required to power a house.