The village of Xcalak (pronounced Sca-Lac) is located in the Mexican Yucatan, on the coast across the bay from Chetumal. Xcalak is a fishing and tourist village of 250 people. It has some of the best fishing and skin-diving to be found in Mexico, but is relatively undeveloped.
The closest CFE (Mexican national utility) power lines are 110 km away and the costs to extend the grid to Xcalak has been estimated at a prohibitive $3.2 million. The village has been powered by diesel generators, but the reliability of the diesels has been very poor. In fact the diesel building (white building in the photo) sports a fine collection of broken-down diesel generators.
In 1992, Xcalak was re-electrified, at a cost of ~$550,000, with a wind and solar hybrid system consisting of six 7.5 kW Bergey wind turbines and an 11 kW photovoltaic array (visible in front of the diesel building). The system also includes a large battery bank (400 kWh) and a 40 kW static inverter. Until mid-1995 the system did not have a working back-up diesel, so all the electricity for the village came solely from the wind and sun. Even now, the back-up generator is used infrequently due to high operating costs and frequent breakdowns.
The system has worked well technically, though a few electronics problems have occurred and one wind turbine alternator was damaged in 1993 due to a wiring fault. Salt corrosion has also been a problem. The system is performing as expected, but, unfortunately, the wind/solar generators can not satisfy the current local demand because consumption has grown to more than three times the original projection. The higher electrical demand is at least partly the result of the fact that the villagers are not charged for electricity. Also, the distribution wiring in the town is in poor shape and promised efficiency upgrades were never completed.
Electricity is typically available 8-16 hours a day, depending primarily on the wind resources. Wind power provides approximately 85% of the generated electricity. A number of institutional and technical improvements are under consideration.
The system was extensively instrumented for the first five yearsand was monitored by the U.S. National Renewable Energy Laboratory and Sandia National Labs to learn more about the real world performance of village hybrid systems. There are now thirteen Mexican villages using wind systems and more installations are under development.