We assess the implications on long-run average energy production costs and emissions of CO2 and some criteria pollutants from coupling wind, solar and natural gas generation sources. We utilize five-minute meteorological data from a US location that has been estimated to have both high-quality wind and solar resources, to simulate production of a coupled generation system that produces a constant amount of electric energy. The natural gas turbine is utilized to provide fill-in energy for the coupled wind/solar system, and is compared to a base case where the gas turbine produces a constant power output. We assess the impacts on variability of coupled wind and solar over multiple time scales, and compare this variability with regional demand in a nearby load center, and find that coupling wind and solar does decrease variability of output. The cost analysis found that wind energy with gas back-up has a lower levelized cost of energy than using gas energy alone, resulting in production savings. Adding solar energy to the coupled system increases levelized cost of energy production; this cost is not made up by any reductions in emissions costs.
E. Hittinger, J. Whitacre and J. Apt, “Compensating for Wind Variability Using Co-Located Natural Gas Generation and Energy Storage,” Energy Systems, Vol. 1, No. 4, 2010, pp. 417-439. doi:10.1007/s12667-010-0017-2
A. Mills, R. Wiser, M. Milligan and M. O’Malley, “Comment on ‘Air Emissions Due to Wind and Solar Power’,” Environmental Science and Technology, Vol. 43, No. 15, 2009, pp. 6106-6107. doi:10.1021/es900831b