Question: How do solar panels work?

Kevin Motherway answered on 13 Nov 2014:

There are 2 main types of solar panels: Photo Voltaic Solar panels that generate electricity and thermal solar panels that heat water.

Photovoltaic panels work by generating Direct Current (DC). When photons of light (essentially energetic parcels of light) from sunlight hit a solar panel they excite the electrons in a semiconductor materials to the point where some of them leap out of the semiconductor and can then flow in a wire. Electrical Current is essentially just electrons in motion. So the brighter the sunlight, the more high energy photons that hit the semiconductor in the solar panel, the more electrons get excited enough to leap out of the semiconductor and the more current it generates. Solar panels are not very efficient as only about 18% of the energy that falls on them gets converted into usable electrical power, but when you have no other handy source of power (like in outer space or in really remote locations) they are a really great way of getting power, but putting them on your roof in Ireland hoping to cut your ESB bill in half isn’t going to work.

Thermal Solar Panels work by passing water through tiny tubes in the solar panel which focusses the thermal energy of the sun (like a glorified bucket painted black, its gonna heat the water on s hot summers day). These can certain help cut down your hot water bill even in Ireland.