Hybrid Energy System Cost Analysis: San Nicolas Island, California

San Nicholas Island has an excellent wind resource, with an annual average wind speed of 7.2 m/s (14.0 knots) as measured by the National Renewable Energy Laboratory (NREL) at 30.5 m (100 ft) at Facility No. 186 in the August 1994 - July 1995 data collection period. Recognizing this, a hybrid energy system was modeled to examine the merits of supplementing the existing diesel generators with amodest portion of wind energy generation. Using conservative assumptions (unfavorable to wind energy) at every step in the spreadsheet model, the hybrid system displayed favorable operation and economics. The levelized cost of energy (COE) for the hybrid case using four 225 kW wind turbines is $0.338/kWh vs. $0.358/kWh for the baseline case. This would create a COE savings of 5.6%. The paybackperiod is 6.97 years, the internal rate of return is 13.1%. The two-turbine case had a COE of $0.342/kWh, saving 4.5%, with a payback period of 5.29 years, and an internal rate of return of 18.2%. The COE for this case is relatively insensitive to annual average wind speed, varying 1% for a 10% change in wind speed. But the payback period is quite sensitive to wind speed, varying 11% to 17% fora 10% change in wind speed.