The difference between on-grid wind farms and off-grid wind farms

With the growing need to discover and explore renewable and environmentally-friendly sources of energy, wind farms are an option many are opting for. With the many problems surrounding energy prices and usage of fossil fuels such as coal and oil, wind farms are now being developed in various parts of the world. With wind being a clean and inexhaustible source of energy, wind farms are a credible replacement for the otherwise standard energy generation processes i.e. coal, natural gas, oil and nuclear generation facilities.

Wind farms essentially constitute a location where a sizeable group of wind turbines are erected for the purpose of energy generation. These turbines work to convert the wind's kinetic energy to mostly electric and sometimes mechanical energy. The turbines, at times even a 100 in number, are interconnected and cover a large geographical area. Powered by the wind's strength and speed, the blades of the turbines transform the wind's kinetic energy to a more usable form of energy. This power from the turbines is collected by an integrated system and then supplied to transformers to increase their voltage, generally at a substation. Electric power supplied by the generators, can be put to work at private homes, businesses, factories, farms etc.

There are two types of wind farming practices, depending on how the energy generated is used i.e. off-grid and on-grid wind farms.

Off-Grid Wind Farms: When wind farms do not outsource their power to electric grids, they are known as off-grid wind farms. The power generated is essentially used for their own, personal purposes. Farmers, factory owners, homeowners or even just the environmentally conscious can choose to generate their own renewable power and put it to use according to their needs. This is also a boon for people living in remote areas, with limited access to electricity. People with their own off-grid wind farms strive to use the power harnessed to beat rising electricity costs and maintain a self sufficiency that can be easier on the wallet and the environment.  In some cases, people tie up their small wind generators to the electric grid and simply transfer the extra, unused electric power back into the grid for monetary credit or later usage. Some wind farm owners also sell their excess power to centralized power utilities. When this is done, utilizing the same power distribution line that carries power to your property or business, this is also known as net metering.

On-Grid Wind Farms: Wind farms that sell the power they produce to electrical grids, qualify as on-grid wind farms. It is basically the production of wind energy for commercial use. Energy projects like these typically involve a PPA or power purchase agreement, between the energy supplier and the buyer. The buyers are normally utilities or bigger co-operative or industrial factions. Power purchase agreements are drawn up to set various guidelines for both the buying and selling parties, involving finances, legalities, damages, the sharing of risk and project timelines among others. Also, stipulated are matters related to environmental issues, a key factor today. Some of the hurdles to overcome in order to ensure a successful relationship for a productive renewable energy project are the ability of existing power grids to handle the newly developing load demands, extensive and overcrowded power lines and transmission issues. Therefore, an extremely important factor that determines the viability of an on-grid wind farm is the transmission study that assesses the current and potential future load (queue) impacts, amongst other technical items, on the existing transmission line to be tied into.