PV - Basic Operation
Photovoltaic solar cells convert sunlight into electricity. It is the same technology that is used to power solar cell calculators and some traffic warning signs. Solar cells are made from semi-conducting materials such as crystalline silicon. The sun’s waves hit a photovoltaic cell and excite the electrons within layers of the cell. These excited electrons jump back and forth, creating electricity. Groups of PV cells are arranged on panels to form a solar module. Solar modules are arranged to form a solar array.
The electricity created in the PV cells is captured by wires running through the cells and the electricity is sent (a.) into your home for immediate use, (b.) into batteries for storage or (c.) onto the grid if you have a grid-connected system (if you have excess electricity that you can't use).
PV panels need to get the most exposure to sunlight as possible while avoiding being in shadow. Therefore, it is best if they are south facing and at an optimum angle to get the most sunlight. Even if not directly south facing they work reasonably well southeast or southwest facing. See Location & Siting.
The electric current generated by PV cells is direct current (DC), or the type of current used in batteries. Most of the appliances (TV, fridge, microwave, electric storage heaters etc.) and other loads (lighting etc.) in Ireland run on alternating current (AC), or the type of current that comes from the grid (ESB). If you decide to use these conventional AC appliances in your building, the DC electricity from the solar cells will need to go into an inverter where it will be turned into alternating current. From the inverter the electricity will then be used by the appliances and other loads in your home or go out into the grid if it is a grid-connected system.