Renewable generation and its integration in New Zealand power system

The New Zealand power system has a peak demand of 3500 MW in the south island and 4500 MW in the north island, thus a total of 8000MW. In 2010, approximately 74.6% of energy came from different renewable sources where hydro alone represents about 57%. The NZ government has announced that the renewable target of 90% needs to be fulfilled by 2025. It seems this target is easily achievable because there is significant additional wind plant and geo-thermal plants under construction or planned for the near future. The installed capacity of wind generation is 565 MW at present and it is expected that this capacity will increase significantly. Thus it will bring with it “intermittency”. This paper describes the New Zealand power system and its market operation. Next it describes the methods by which the wind generation intermittency can be overcome considering New Zealand river chain system and also by Demand Management. A mathematical model is presented showing how the demand response could bridge the intermittency created by wind generation. Result of a case study is summarized and presented.