Dynamic exergy analysis for capacity expansion of regional power-generation systems: Case study of far West Texas

Abstract

The global electricity supply from non-hydro renewables, mainly wind and solar, is currently growing at a high rate, and it is expected that this trend persists. In the near-to-medium term, the power produced by breakthrough fossil fuel technologies might also grow intensively. These expansion patterns can be optimized in a regional context, which translates into a multidimensional problem. As part of the solution, a procedure to determine maximum allowable growth rates for alternative power-generation technologies is developed and exemplified in this paper. The model applies a dynamic exergy analysis based on the cumulative exergy-consumption concept, expanded to include emissions abatement. A Gompertz sigmoid growth is assumed and constrained by both exergetic self-sustenance and regional energy resource availability. Far West Texas is the selected study region. The deployment of alternative technologies (wind turbines, photovoltaics, hybrid solar thermal parabolic troughs, and solid oxide fuel cells) to meet the regional power demand is projected assuming backup capacity by a conventional technology (natural gas combined cycle). The results show that during the next decades the new capacity demand may largely be met by deploying alternative technologies, with a cost in primary resources that can be minimized through a proper allowance for exergy reinvestment.