Smaller systems aren't cost-effective.
Dr. Gary C. Young is a consulting engineer and founder of GYCO Inc. His company does process & project engineering as well as research and development in the process industry.
It’s time for a reality check on the commercial viability of wind farms. Are large wind systems more economical than small wind systems?
A typical small wind-energy generation system is a 10-kW turbine. A wind turbine output calculator1 puts the capacity factor at 23.18 percent and estimated annual output at 20,283 kWh per year. Mike Bergey of Bergey Windpower Co. listed a typical capital cost of such a system at $45,000.2 At an interest rate of 5.50 percent over
20 years, and an operation and maintenance cost of 2.0 cents/kWh, analysis indicates a break-even cost for producing the wind energy of 20.31 cents/kWh (see Case #3, column 7 in the table). Note that the capacity factor is the amount of system capacity converted to energy for the time period under consideration. When the capacity factor is increased from 20.31 percent to 35 percent, the break-even cost becomes 14.13 cents/kWh (see Case #2, column 7 in the table).
A $323 million project consisting of about 200 wind turbines with a capacity of 310,000 kW and no subsidies indicates a break-even price for wind energy of 3.359 cents/kWh (see Case #1, column 7 in the table).