Using the sun’s energy to light our homes, both inside and using solar outdoor lights, is an interesting prospect. Especially as this could be done in such a way that we would be free from electricity bills. However, the charges associated with installing the necessary equipment is off putting to a lot of people.
Solar energy is most commonly converted into electricity to power lighting, through the use of photovoltaics.
A photovoltaic cell consists of semi-conducting materials, such as silicon, which absorbs some of the sunlight that falls on it. A number of these cells are interconnected in series or parallel, to form a solar panel. The energy produced by such panels depends upon the number of individual cells within the panel, and the way in which they are organised. Depending on the arrangement, the photovoltaic cells in a solar panel produce voltages in increments of 12, such as 12, 24, 36, 48 volts, for example.
Sunlight photons, which are streams of energy particles, generate electricity when they hit the silicon atoms of the solar cells. Fresnel lenses and mirrored dishes concentrate these photons onto the photovoltaic cells. The electrons are freed when they hit the negatively charged plates, producing an electric current. This can be drawn off and used externally for things such as lighting.
One advantage of using photovoltaics to generate electricity is that it doesn’t produce any pollution. This goes for noise aswell since, as it has no moving parts, it is silent during operation. It also requires no or very little maintenance.
Most photovoltaic systems are designed to supply electricity as and when required, and deep cycle batteries to store electricity generated by the solar panels. The power stored can then be released at night, for example, to run indoor and outdoor lighting. To control the charge and limit the discharge, these batteries require DC/AC inverters.
After the initial cost of the panels, inverters and other equipment you get free electricity generation and can light up your home with clean solar power. Unlike solar heating, lighting can more easily pay for itself.