Transforming a solar-rich county to an electricity producer: Solutions to the mismatch between demand and generation

This study solves the mismatch in a solar-rich county for evolving into a giant electricity producer. The temporal mismatch between renewable generation and electricity consumption exists globally due to renewable-energy intermittency , which can be measured by the insufficient ratio. Through examining the unique county in China whose renewable supply reaches demand, it is found that 45.6% of annual demand cannot be fulfilled by renewable energy instantaneously. When renewable energy generation is 1.5 times the demand and solar proportion is 40%, the insufficiency ratio is reduced to 29.0%. Since adjusting the renewable profile could partially resolve this mismatch, electrical energy storage is further considered. When storage capacity is optimized, the capacity is reduced by 76% if renewable generation is expanded to 1.5 times demand. However, electrical energy storage efficiently stabilizes daily operations but fails to counter the seasonal mismatch effectively. Therefore, the seasonal mismatch should be eliminated by exploiting controllable zero-carbon energy, such as biomass power . Eventually, the required storage capacity would be cut by 98%, while the storage and additional energy cost would be reduced by 87%. • A solar-rich county needs to evolve into a giant electricity producer for cities. • The impact of renewable-energy penetration and composition on mismatch is examined. • An optimal algorithm of storage capacity is proposed when renewables exceed demand. • Electricity energy storage can effectively solve diurnal mismatch. • Seasonal mismatch should be countered by additional zero-carbon energy.