Performance - Wind Energy: Renewable Energy and the Environment - page 164

Bergey 1.5 kW Aeromotor

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FIGURE 8.15 Predicted annual water pumped by 1.5 kW wind - electric water pumping system and farm
windmill.

rural areas, and if extended, it is heavily subsidized. These people depend on wood, biomass, or dung
for cooking and heating, mainly collected and cared for by women and girls.
For remote villages and rural industry the standard is diesel generators. Remote electric power
was estimated at 10.6 GW in 1990. Of that there were 133,816 diesel gensets, ranging in size from 5
to 1,000 kW, with a power rating estimated at 9.1 GW. In Canada, there were more than 800 diesel
generating sets with a combined installed rating of over 500 MW. Diesel generators are inexpensive
to install; however, they are expensive to operate and maintain, and major maintenance is needed
from every 2,000 to 20,000 hours, depending on the size of the diesel genset. Most small village
systems only have electricity in the evening. Wind-diesel [23] is considered because of the high
costs for generating power in isolated locations, and by 1986, more than a megawatt of wind tur-
bines were installed with existing diesel systems.
The Kotzebue Electric Association (KEA), Alaska, grid has six diesel generators with a com-
bined capacity of 11.2 MW. The annual average load is about 2.5 MW, with a peak load around
3.9 MW, and the minimum load is around 1.8 MW. Loads are greatest during the winter months for
heating and lighting. KEA maintains a high reserve capability to prevent loss of power during the
winter. Critical loads include the heating of the town water supply. Typically, KEA runs two genera-
tors continuously during the winter, with the rest as backup. KEA consumes, on average, 5.3 million
L of diesel fuel, with an average efficiency of 4 kWh/L. The energy costs for the diesel generators
were estimated at $0.50/kWh ($1998). There is a potential ecological problem, as huge bladders of
diesel are stored on site during the short summer season when the river is navigable by barge to off-
load a year's supply of fuel at a time.
A demonstration project of adding wind turbines to an existing diesel plant is the KEA Wind
Farm [24]. The ten wind turbines (Atlantic Orient, 50 kW, 15 m diameter) are located on a relatively
flat plain 7 km south of Kotzebue and 0.8 km from the coast ( Figure 8.16 ) . The site is well exposed
to the easterly winter winds and the westerly summer winds, with an annual average wind speed of
6.1 m/s. The cost of energy for the wind turbines was estimated at $0.13/kWh for the first 2 years of
operation. The first three turbines were installed in July 1997, and seven more turbines were added
in May 1999.
The ten wind turbines should reduce the annual fuel consumption by about 340,000 L, which is
about 6% of normal fuel requirements. At the 1998 cost of fuel to KEA, $0.25/L, this would save
KEA and its member-owners around $84,600 each year. In addition to direct fuel cost savings,