This is around six times the current installed capacity, reports Econnect Ltd, a British firm which has recently completed a study to determine whether control of customer loads can increase the potential for wind power on "weak" parts of the electricity distribution system.
The study concludes that load management is a viable way of achieving this aim. It estimates that weak grids serve about 2.2 million households in zones with existing wind farms. Consumer loads, such as electric heating systems, could be managed by wind plant operators through the use of remote switching. The economics of the system appear promising, says Econnect, with reasonable returns on investment to participating consumers.
It estimates that 3200 extra 500 kW wind turbines could be installed on weak networks in the UK if load management techniques at the consumer level were adopted. The practicable wind energy resource of the UK would be increased substantially, argues Econnect, which believes the concept could have far reaching implications for the future of electricity generation in general, especially where systems have been privatised, as in the UK.
The study was carried out as part of the Renewable Energy Programme managed by the Energy Technology Support Unit (ETSU) on behalf of the Department of Trade and Industry. It examined technical methods for managing loads, commercial methods for achieving the load management, and the potential in the UK for such load management to increase the potential for wind power on the grid.
Econnect points out that in many rural areas ideal for wind energy generators the capacity of the local distribution network is a serious impediment. Most electricity supply systems are designed to transport electricity from central power stations and become progressively weaker at their extremities where all they have to do is serve customers such as farms and villages. Strengthening these weak networks is often an expensive option for smaller wind schemes.
Controlling customer loads on such weak networks could make it possible to increase the amount of wind generation that can be installed. Customer loads can be managed remotely by a number of techniques such as radio tele-switching, which is already used by Public Electricity Suppliers to control loads on domestic heating systems. The Econnect study discovered that not only were consumers willing to participate in such a scheme, but that it could be made financially worth their while.
The study included a theoretical simulation of wind controlled load management. Wind energy generation information data, based on measured wind speeds at a proposed site, were combined with half-hourly load data obtained for a typical "weak" feeder. This enabled load flows on the simulated network over a year to be modelled for different combinations of wind power, the number of consumers participating and the amount of managed load on the network. The use of power factor control to manage voltage fluctuations on this network was also investigated, along with the practical methods available for carrying out load management on domestic systems by remote control.