Market Sensitivity of Solar-Fossil Hybrid Electricity Generation to Price, Efficiency, Policy, and Fuel Projections

Ideally, new electricity generating units will have low capital costs, low fuel costs, minimal environmental impacts, and satisfy demand without concerns of intermittency. When expanding generating capacity, candidate technologies can be evaluated against criteria such as these. Alternatively, it may be possible to pair technologies in such a way that the combination addresses these criteria better than either technology individually. One such approach is to pair concentrated solar power and natural gas combined-cycle units. This paper analyzes how an integrated solar combined cycle (ISCC) facility could fare in the larger US electricity production market, although the results are generalizable to a wider range of technologies. Modeling results suggest that a critical consideration is the extent to which ISCC qualifies as being renewable under state-level renewable portfolio standards (RPSs). The technology would be utilized at a higher level if it fully satisfies an RPS; however, even if the technology does not satisfy an RPS, it would be market-competitive if optimistic goals for capital cost and avoided natural gas purchases are met. Furthermore, if used in parts of the country with strong solar resources, ISCC could produce as much as 14% of national electricity generation in 2050. Whether adoption of ISCC leads to reduced air pollutant and greenhouse gas emissions is dependent on the technologies it displaces. Under default assumptions, the new ISCC capacity primarily displaces renewable and natural gas facilities as opposed to facilities with higher air pollutant emissions. Thus, the air pollution benefits of ISCC may be limited.