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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.
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