A solar PV system is a system that directly converts the suns light into electrical energy. This electricity can then be fed into the electrical system of the house, office or factory where it can be used on it’s own, or in conjunction with the main electrical supply. Solar PV can therefore directly reduce or remove the electrical costs of the user. In some cases electricity can even be exported by larger solar PV systems onto the electricity grid, providing a source of income.
The science bit
The PV panels are positioned so that maximum light will shine upon them over the course of the day. Light which hits the panel, passes directly through the glass plate, found on the surface of the panel, and into the silicon layer of the panel. The energy from the light excites electrons within the silicon semiconductor layer of the panel, creating an electrical current. This current is then passed through a piece of electrical switch gear called an inverter, before going on to the main fuse board. The inverter converts the current from DC (like in a battery) to AC (like in a house). From this point the electricity supply the needs of the building. If the demand is too great, electricity from the main electricity supply can combine with it to provide for the demand. If it is too little the electricity can charge a battery, or be fed onto the national grid. As there is no sun light at night, a large battery would be required to keep a supply over the course of the night.
So… Do they work?
In comparison to other renewable technologies, solar PV panels are relatively immature. Most experts believe that PV would be the ideal solution to the worlds energy problems. The sun shines every day, they are relatively unobtrusive, they can be put in the places where energy is being consumed. The problem is, that for their cost, they can’t compete with other technologies. At the moment solar PV is primarily used on road signs and remote installations, places where the cost of running an electric cable is prohibitive, but for generating electricity for your home, the other technologies win out.
NOTE: Technology is moving forward fast… don’t give up on it just yet. Check out this site for an ongoingcommentary