Conventional Generation Dispatch Methods in Systems with Intermittent Resources

Abstract

In this chapter, we study the impact of different-sized wind parks on Flores and São Miguel power systems and estimate the ideal number of wind turbines for both islands. If the number of wind turbines is over the ideal, the energy produced might not be injected into the grid, with all the costs associated with that. To estimate the wind energy available but not injected into the grid, we use a method based on Unit Commitment (UC). For the UC, we assume that geothermal units (São Miguel) and hydro generation without a reservoir (noncontrollable) behave as negative loads. Hydro plants with a reservoir are dispatched for peak-shaving, with daily energy production restrictions. Available wind power, which is cheaper, has priority over the power produced by these hydro plants. Since there is no storage available, several fuel units are kept running at minimum power, to be able to compensate for wind fluctuations: newer generators are allocated first (it is assumed that newer generation is more efficient) and the fuel units allocated must be able to compensate for all the energy variation from wind turbines.