Reducing curtailment of wind electricity in China by employing electric boilers for heat and pumped hydro for energy storage

Abstract

Accommodating variable wind power poses a critical challenge for electric power systems that are heavily dependent on combined-heat-and-power (CHP) plants, as is the case for north China. Pumped hydro storage (PHS) and electric boilers (EBs) are two of the strongest technological options under discussion in China to address this challenge, but rigorous quantitative analyses of their effectiveness rooted in actual system data are lacking. An improved unit-commitment based power system chronological simulation is applied to evaluate potential benefits from PHS and EBs in West Inner Mongolia (WIM), where CHP capacity is projected to increase to 33.8 GW by 2020. A business-as-usual (BAU) reference model assumes deployment of 20 GW of wind capacity. Compared to BAU, expanding wind capacity to 40 GW would allow for a reduction in CO 2 emissions of 33.9 million tons, but at a relatively high cost of US$25.3/ton, reflecting primarily high associated curtailment of wind electricity (20.4%). A number of scenarios adding PHS and/or EBs combined with higher levels of wind capacity are evaluated. The best case indicates that a combination of PHS (3.6 GW) and EBs (6.2 GW) together with 40 GW of wind capacity would reduce CO 2 emissions by 43.5 million tons compared to BAU and at a lower cost of US$16.0/ton. Achieving this outcome will require a price-incentive policy designed to ensure the profitability of both PHS and EB facilities.