Wind Farms and the Electricity Network
Unless a wind project is to be established to provide electricity to a remote, isolated location or to an industrial facility onsite the wind turbines will need to connect to the national grid. Commercial wind turbines are used to feed directly into the National electricity grid for distribution with power from the entire energy supply mix.
Because wind energy is an intermittent source of power it is important that the use of wind power is compatible with the power quality requirements of the grid. Ireland's electricity grid system comprises a localised distribution system (10, 20, and 38 kV network) and a higher voltage transmission system (110, 220 and 400kV network).
Updated maps of the distribution and transmission networks are available on the ESB Networks website.
Network Statistics and Maps
Connection to the Network
Wind farms have until recently been most commonly connected to the distribution system. As wind farm sizes increase and local network power capacity differs, many wind farms are connected to the transmission system. By 2010 the split between transmission connected and distribution connected wind capacity was 50/50.
Prospective wind farm operators will need to identify which power system is the most suitable for their project to connect to and this will have a definite bearing upon the costs of the project. It is important for developers to employ qualified and experienced engineers to fulfill this task.
Ideally wind farms should locate within approximately 15 km of a suitable grid connection point to minimise the associated costs. The electricity will be transported within the wind farm site by cables underground and from the site by overhead power cables usually mounted on wooden poles similar to those seen along most roads. These take the electricity to a nearby substation where it can link up with the national electricity grid.
The Transmission System
A high voltage network using heavy duty wires to transport bulk power from the generating stations to transmission - distribution stations located at the major load centres (usually cities and larger towns) They are equivalent to the motorways and dual carriageways of the electricity network. The transmission system transports high voltage electricity to reduce losses over distance.
The Distribution System
A network of low and medium voltage wires that transport power from the transmission - distribution stations to small towns, industrial areas and individual customers. They are equivalent to the intermediate and minor roads of the electricity system. Different low voltages are used so that electricity is transported to medium and small loads (customers). Lower voltages than used on the transmission system are sufficient.