Techno-economic analysis of pressure gain combustion gas turbine for island grids with high renewable solar share

This is the authors' abstract. We don't add key points for this paper.

• A PGC gas turbine with 53.1 % combustor pressure gain at nominal conditions can reduce fuel consumption and carbon dioxide emission by 14.3 %. • For the same engine size, using a larger number of smaller PGC generators can offer a better solution, environmentally. • Even under the most optimistic CAPEX, PGC will not be able to outperform reciprocating engines economically for island production. This paper presents a techno-economic analysis of a hybrid dispatch strategy on an island using innovative pressure gain combustion (PGC) and conventional technologies in the presence of a high share of renewable solar photovoltaics (PV). Electricity dispatch was studied for six different hybrid plant configurations for a complete year, with renewable installed capacity varying from 10 MW e to 130 MW e to meet the variable 100 MW e peak demand. Optimization of the operational strategy was performed in W-ECoMP, a modular software tool developed by Thermochemical Power Group (TPG) at the University of Genova, Italy. Due to the absence of performance data for the emerging PGC technology, its off-design curve was estimated by upscaling the off-design performance of a conventional simple cycle gas turbine based on the results of the design point thermodynamic cycle analysis. The performance of different hybrid plants was compared in terms of total electricity production, fuel consumption, curtailment, carbon dioxide emission and cost. The effect of the number of generators in the plant and generator size was also investigated in terms of technical and environmental performance. Results showed that compared to CGT, a similar-sized PGC gas turbine with 53.1 % combustor pressure gain (with practical PGC combustor losses) reduced the annual fuel consumption and CO 2 emissions by 14.3 %, with no risk on power delivery to the users. Similarly, PGC GT was able to reduce the levelized cost of electricity generation (LCOE) by 12.8 €/MWh (12.4 %) and 9.2 €/MWh (11.2 %) without solar and with maximum solar hybridization, respectively. Although PGC gas turbines performed better than conventional GT, they were outperformed by ICE engines even under the most optimistic CAPEX, efficiency and off-design performance and therefore, most likely, practical PGC GTs with higher CAPEX due to technology development costs will not be able to replace ICE engines for island production. Overall, the economic performance of all plants was found to be more strongly dependent on the generator efficiency as compared to CAPEX. Finally, the environmental benefits of high fuel prices were highlighted through a sensitivity analysis that showed the driving potential towards more renewable penetration with increasing fuel prices.