The planning and design stage of wind farm development often fails to pay enough attention to focusing on obtaining a connection to the electricity supply and distribution networks.
This has in part been due to the Distribution Network Operators (DNOs) still having little comparative experience in connecting into new generating systems which makes finding information for the purposes of assessing the feasibility of a wind farm proposal very difficult. Such information is important as getting this part of the planning process wrong can have ramifications on the design and build of a new proposed wind farm development.
Every site can be said to have some connection potential to the electricity grid with the governing factor being cost. The costs will be affected by such things as labour, length of cabling required, roadworks and the provision of a substation. Interestingly the cheapest connection point may not necessarily be the nearest supply line but is more likely to be the supply line with the lowest load upon it.
Sites will require at the very least a 33KV connection which also requires connection into the nearest 33kv distribution system as well as the procurement of a 33kv substation.
he steps in connecting into the electricity supply may look something like this:
STEP 1 initial discussion with DNO on nearest adequate connection points and likelihood of constraints on size of development.
STEP 2 DNO is provided with information on machine size and location. DNO considers potential connection point and provides sample agreement to developer.
STEP 3 Formal connection application submitted to DNO and detailed costing prepared by DNO.
STEP 4 DNO is instructed to provide connection at agreed cost.
STEP 5 DNO tests the connection and developer tests and commissions the generating plant. The connection is made live.
One of the biggest challenges facing the developers of wind farms in the future will be securing a balance between the preference for a remote location in terms of its visibility with the preference for a location where the capacity of the distribution network is highest i.e. those areas where population and economic activity are in abundance. Losses are also incurred where electricity is transmitted on the national grid system over long distances. Such factors will have major cost implications for the siting of renewable generation in the UK and may create an increasing preference for sites closest to demand where costs will be lowest.