Applications and Wind Industry - Wind Energy: Renewable Energy and the Environment - page 202

Energy Board. In Denmark, at the end of 2005, individuals or wind turbine cooperatives owned 83% of
the 5,293 wind turbines. In terms of capacity, privately owned wind turbines had 77% of the capacity.
The capacity percentage will probably decrease with the installation of more offshore wind farms.
10.4 WIND-DIESEL
For remote communities and rural industry the standard is diesel generators. Remote electric power
is estimated at over 11 GW, with 150,000 diesel gensets, ranging in size from 5 to 1,000 kW. In
Canada, there are more than 800 diesel gensets, with a combined installed rating of over 500 MW.
In the State of Chubut, Argentina, they have village systems using diesel generators, which range
from 75 kW in a small village to 1,250 kW for a large village. Because the systems are subsidized,
from the state to the national level, it is difficult to determine the actual cost of electricity. In
general, past costs were $0.20 to $0.50/kWh; however, it is now quite a bit higher, as oil is over
$100/ bbl.
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.
In Canada there are more than 300 remote communities with diesel-generated electricity, and
coastal Alaska has around 90 villages, which have the potential for displacing diesel fuel with wind
(see Section 8.6 for wind-diesel performance at Kotzebue, Alaska). Australia, Argentina, northeast
Brazil, Chile, China, Indonesia, Philippines, coastal sub-Sahara Africa, and of course other coun-
tries with isolated villages and islands have the potential for wind-diesel systems. The design of
wind-diesel systems plus modeling techniques and simulation is better now that operational experi-
ence at a number of sites is available.
Wind-diesel systems were developed and tested at Riso National Laboratory, Denmark;
Netherlands Energy Research Center, Petten, Netherlands; Atlantic Wind Test Site, Prince Edward
Island, Canada; National Renewable Energy Laboratory, United States; United Kingdom; and at
other locations. Primary work was on developing wind-diesel systems for the retrofit market. This
market would be for existing diesel generators in windy locations, which would be over 50% of the
installed capacity. A wind biodiesel system is being tested at USDA-ARS, Bushland, Texas [15].
Wind-diesel [16, 17] is considered because of the high costs for generating power in isolated systems,
and by 1986, more than a megawatt of wind turbines were installed with existing diesel systems. Today,
a very rough estimate indicates there are around 200 wind-diesel systems, but the market is changing
rapidly with the high cost of diesel fuel. Two manufacturers expect to install over 1,200 MW of wind at
existing diesel plants in 2008-2009. Simulation models for wind-diesel systems are available.
There are two aspects: addition of wind turbines to existing diesel power plants as a fuel saver,
and now integrated wind-diesel or wind hybrid systems for village power. Wind-diesel power sys-
tems can vary from simple designs in which wind turbines are connected directly to the diesel grid
( Figure 10.2 ) , with a minimum of additional features, to more complex systems [18]. Wind-diesel
power systems have peak demands of 100 kW to a megawatt, based on AC bus configurations, and
storage is needed for high penetration. However, there are a number of problems in integrating a
wind turbine to an existing diesel genset: voltage and frequency control, frequent stop-starts of the
diesel, utilization of surplus energy, and the use and operation of a new technology. These problems
vary by the amount of penetration ( Table 10.5 ). Wind turbines at low penetration can be added to
existing diesel power for large communities without many problems, as it is primarily a fuel saver.
One solution for high wind penetration is the use of flywheels or battery storage [19, 20].
There have probably been more than 200 wind-diesel projects from prototypes to operating
systems. Reports on operational experiences from eleven wind-diesel installations are available
from the 2004 workshop [21]. The U.S. Air Force installed four 225 kW wind turbines connected
to two 1,900 kW diesel generators (average load, 2.2-2.4 MW) for a low-penetration system on
Ascension Island [22]. Average penetration was 14-24%. Tower height was limited to 30 m due to