Creating electricity from the sun is a technology that every one of us knows well. It could be through pocket calculators, photovoltaic panels in your home or a satellite. It can all get the job done.
But for those who are curious, how do you explain solar electricity? What is a PV power and just how much energy can a PV produce? This is solar electricity explained.
Solar Electricity is generated by using photovoltaic (PV) technology which converts the free energy from the sun into electricity from sunlight. Through photovoltaic systems, sunlight is used to power electrical equipment like household appliances, lighting and computers. But note that this is not the thermal technology used for heating space and producing hot water.
A photovoltaic cell consists of two or more thin layers of mostly silicon which is a semi-conductor. Once the silicon is exposed to light, electrical charges will be generated and conducted away by metal contacts as direct currents (DC). A single PV cell is only capable of a small electrical output that multiple cells are needed to be connected together and encapsulated behind a glass to form a panel, also called as a module.
The PV panel is then the principal building block of the system where any number of panels can be connected together for the desired solar electricity output. But the PV equipment does not have moving parts so it only requires minimal maintenance. It generates electricity without producing and emitting greenhouse gases and it operates silently.
PV systems are actually used to supply solar electricity to city buildings which are also connected to the normal local solar power network. PV systems also supply power to garden lights or even to remote relay stations. But the use of photovoltaic technology on buildings is ideal because it provides a noise and pollution free solar power without needing extra space.
PV systems are set up into buildings in different ways. Ideally, it should be on sloping rooftops where the panels can simply be mounted using frames. It can also be built into the actual building fabric, such as PV roof tiles, and alternatively be incorporated as canopies, building facades and many other applications.
There are various types of PV cells. Monocrystalline silicon cells, the most efficient of this technology, are made of cells saw-cut from one cylindrical crystal of silicon. But the disadvantage is that it is of higher costs compared to the other PV technologies.
Multicrystalline silicon cells made of cells cut from an ingot of melted and re-crystallized silicon tend to be slightly less efficient. Thick-film silicon is an encapsulated multicrystalline technology wherein the silicon is deposited in a continuous process onto a base material which results to a fine-grained sparkling appearance. Amorphous silicon cells, however, are made from silicon atoms in a thin homogenous layer instead of a crystal structure but being a thin film, it effectively absorbs more light.
But the typical PV system configuration has the building-mounted PV array consisting of typical photovoltaic panels connected together with a rated output of 75 to 120 watts peak each. An inverter is also used to convert the low voltage direct current (DC) into the higher voltage alternating current (AC). Other components include the array mounting structure, cables, switches and a meter to make sure that you, as the system owner, can be credited for any solar electricity fed into the main supply.