Utility scale hybrid wind-solar thermal electrical generation: A case study for Minnesota

The performance of a hybrid wind-solar power plant in southwestern Minnesota is modeled for a 2-yr period using hourly wind and solar insolation data. The wind portion of the plant consists of four interconnected wind farms within a radius of 90 km. The solar component of the plant is a parabolic trough solar thermal electric generating system using a heat transfer fluid that drives a steam turbine. The market value of energy produced, retail value of energy produced, and levelized cost of energy of the hybrid plant are compared to those of an energy equivalent wind-only plant. Results show that adding solar thermal electric generating capacity to a wind farm rather than expanding with additional wind capacity provides cost-benefit trade-offs that will continue to change as the two technologies evolve. At the present time, we find that capital cost and levelized cost of energy favor a wind-only plant while electric load matching favors a hybrid wind-solar plant. Regional differences in the solar resource in the US influence the economic viability of the hybrid plant, and a comparison using the present model is made with one location in the Southwest. The hourly data analysis presented here is a possible tool for evaluating the overall economic feasibility and generating characteristics for a hybrid wind-solar thermal electric power plant for any location with available wind, solar, electric load, and price data.