Variously worldwide types of deregulated electricity markets and their respective transmission congestion management schemes

In this paper, four practical and successful deregulated electricity markets: the old England & Wales Pool, the British Electricity Trading and Transmission Arrangements (BETTA), Nordic Pool and PJM interconnection will be briefly explained and discussed on their histories, structures, rules and also advantages and disadvantages. The old England & Wales Pool was a typical Pool type market which was one of the first successful electricity market deregulations but now had been replaced by the BETTA which is based on the bilateral and balancing mechanism. Nordic Pool and PJM are hybrid markets which combine both pool and bilateral principles. With maturing deregulated mechanism, transmission congestion becomes an urgent problem for all markets. Uniform marginal price, locational marginal price and zonal price are three typical methods in Pool and Hybrid market for congestion management. Locational marginal price is regarded as more efficient than other two when it comes to the market power dilution. In bilateral market, four transaction curtailments based on four rules: first come first serve, pro rata, minimum-net curtailment and price based are utilized to relieve congestion.