"I'd
put my money on the sun and solar energy.
What a source of power!I hope we
don't have to wait until oil and coal run out before we tackle that"
Thomas Edison
What
is Solar?
Solar PV systems, or photovoltaics, offer consumers the ability to generate electricity in a clean, quiet and reliable way. Because the source of light is the sun, they are often called solar cells. The word photovoltaic comes from “photo”, meaning light, and “voltaic”, which refers to producing electricity. Therefore, the photovoltaic process is “producing electricity directly from sunlight.” Photovoltaic (PV) cells convert sunlight directly into electricity without creating any air or water pollution. PV cells are made of semiconductor material. When light enters the cell, some of the photons from the light are absorbed by the semiconductor atoms, freeing electrons to flow through an external circuit and back into the cell. This flow of electrons is electric current.
Understanding electricity
Electricity is the flow of electrons through a wire similiar to how water flows through a hose. To get the water moving you open a faucet...since the water is under pressure it moves to the open faucet where there is less pressure. Electricity flows in the same manner. The difference in pressure between one prong and another makes the electricity flow down one wire, and then to the appliance. This difference in pressure is called "volts". The amount of electricity or water that flows is called "current" and is measured in "amps". The resistance to flow that the wire or hose(think of a kink) offers is measured in "ohms".
Types
of Solar Systems
Grid-Tie systems
Grid-connected photovoltaic systems are the most common type as they make use of the existing electricity grid. They are simpler in design and easier to install. The electricity produced during the daytime is either used by the property owner, or directed back into the electricity grid, which is then credited back to the homeowner by the utility co., this is called "net-metering". At night, or on dark days when the panels do not produce sufficient power, electricity can then be brought in from the grid at a much lower rate. Grid-tie systems usually range in size from 1kw-20kw.
Off Grid systems/Stand Alone Systems
Off-grid systems are generally employed in remote locations without utility grids. It's a good solution in an area where running a line to the local utility grid is prohibitively expensive, or an area where blackouts and brownouts are relatively common. With an off-grid system, your solar energy system would supply all of the power a cabin, home or business would need.
Off-grid systems completely relieve you from dependency on electrical grids. Off-grid systems typically require a larger up-front investment than grid-tie systems. This is, in large part, due to the greater demands on the system. A grid-tie usually supplements a home's energy demands, reducing the amount of energy required from the utility grid. An off-grid system is responsible for providing all power - appliances, lighting, and the electricity required for other utilities.
