Economics - Wind Energy: Renewable Energy and the Environment - page 257

Small hybrid systems are available, which usually can be set up as modular systems.

Company Size Wind PV Battery Inverter Energy

kW kW kW kWh kW kWh/year $

Bergey 10.1 7.5 2.6 84 6 12,000 57,000

Bergey 1.2 1.0 0.18 10.6 1.5 1,200 7,800

Southwest 1.3 0.40 0.88 750

Most manufacturers do not supply prices on their websites. Notice that shipping and installation
to remote locations will increase the cost, sometimes to double the cost of the energy components.
From the initial cost and energy production the cost of energy can be estimated.
For village power, which source do you choose: wind, photovoltaic, or hybrid wind/PV? For the
hybrid system, a life cycle cost analysis would determine the ratio of wind to PV. The advantages
of PV are no mechanical moving parts and everything is at ground level. For comparison, suppose
the local resources for both wind and solar are good, and a 20 kW system is needed for village
power. The capacity factor for wind is 25%, and for solar it is 4 h/day at peak power, 80% sunshine.
The estimated yearly production for wind is 43,000 kWh and for PV is 6,000 kWh. Also, installed
cost for wind is cheaper than installed cost for PV, so the reasons for choosing wind power are
obvious. That is also the reason that hybrid systems have more wind than PV power, five or more
times greater.

12.8 SUMMARY
Wind farms are the cheapest renewable energy source for generating electricity, as the cost of energy
(COE) from wind turbines has decreased from over $0.50/kWh in the 1970s to 0.06/kWh in 2003
(Figure 12.4). The numbers in Figure 12.2 represent cost of energy for a class 6 wind resource, and
then starting in 1995, the numbers were shifted to represent class 5 and class 4 winds; therefore,
the range is at least 0.02/kWh [18]. Notice that the COE projections for 2005 and later are already
wrong, primarily because of the increased cost of materials and oil. Since 2003 the COE for wind

12

10

8

6

4

2

0

1990 1995 2000 2005 2010 2015 2020

FIGURE 12.4 Cost of electricity from wind turbines and projected future costs. Solid lines for high and
medium wind regimes; dashed lines, bulk power generation. Values from NREL graph.