Solar cells are often used in large quantities to form an array which can produce significant amounts of energy. These solar power stations are very rare in this country but are more common elsewhere, such as in North America. Arrays generally run the cells in series/parallel with each other so that the voltage output is limited to between 12 and 50 volts. This is done to minimize power losses and also for safety.
Image taken from www.darvill.clara.net without permission
The daily energy output from a photovoltaic panel will vary according to factors such as season, weather, orientation and location. On average, in summer, a panel will produce about five times it's rated power output in watt hours per day and in winter twice that amount. For example, in summer a 50 watt panel will produce approximately 250 watt hours of energy.
Trackers are often used in solar power stations which keep the panels permanently facing the Sun. These can almost double the output of an array but other factors such as cost and increased complexity need to be considered when deciding if they are economically viable. The graph below compares power output for a tracked and a non-tracked array.
Image taken from http://acre.murdoch.edu.au/refiles/pv/text.html without permission
Solar power stations often require some type of energy storage when the Sun is not shining or during cloudy periods. Special lead acid batteries are used which can discharge half their energy several thousand times before they deteriorate. Each battery is usually 2V and a number of batteries are used to give the necessary power rating.
Inverters are also needed to transform low voltage DC power into high voltage AC power. Backup or auxiliary sources of power are also needed for when it is not economical to provide battery storage for long periods of time such as during extended cloudy periods. Wind generators can be used, as can small petrol or diesel generators.
