Optimization of a small wind-based hybrid electrical grid on the island of San Cristobal in the Galapagos, Ecuador.

摘要

In October 2007, three wind turbines with a total capacity of 2.4 MW were installed and began commercial operation on the island of San Cristobal in the Galapagos, Ecuador. However, because of the intermittency of the wind resource and the mismatch between the wind power production and the electric demand, 56 percent of the wind-based electricity is wasted. As a result, 57 percent of electricity demand is still met by three 650 kW diesel generators.;This study investigates the potential of three diesel fuel reduction approaches: (1) lowering the electric demand by replacing existing refrigerators and light bulbs with energy efficient units, (2) introducing electric vehicles (EVs) and E-scooters (E-scooters), as a way of storing wind electricity, (3) using a demand response (DR) system as a load shifting strategy to more effectively capture the excess wind resource. DR is utilized through two approaches. The first approach, temporary load-shifting (TLS), requires deferrable loads to be turned off for sufficient time for a generator to put on line, which can reduce the need for spinning reserve. The second approach, permanent load shifting (PLS), defers a portion of the load, up to several hours per day, to another time to utilize the excess wind resource. Each strategy was examined through its fuel saving potential (liter/yr), cost of saving fuel (;The analysis revealed that replacing lighting in addition to PLS offers the highest potential for diesel savings and a cost effective solution. Replacing refrigerators was not found cost-effective if ElecGalapagos paid the full purchase price. Although the diesel saving potential of EVs was found to be high, the potential environmental damage associated with the introduction of lead acid batteries may make them difficult to introduce them on the island. The costs of advanced batteries, such as lithium ion batteries, fail to be cost effective.