The role of highly energy-efficient dwellings in enabling 100% renewable electricity

One of the key challenges to achieving high-percentages of renewable electricity supply is the temporal mismatch between non-dispatchable renewable supply and peaks in electricity demand. These challenges become more pronounced as the timescale of this mismatch extends to seasons. Standard policies emphasise supply-side solutions that will result in underutilized supply, storage and transmission infrastructure, and significantly increased decarbonisation costs. Less attention has been placed on demand-side solutions and, in particular, the potential role of high-performance buildings in reducing the demand for electrical heating in winter, addressing the seasonal supply-demand mismatch. This paper quantifies the potential future reduction in winter electrical heating that could be achieved through widespread uptake of energy efficient dwellings in New Zealand a country with a high percentage of renewable electricity. The results show that rapid uptake of currently achievable best-practice standards could reduce the winter-summer demand variation by 3/4 from business as usual by 2050. Therefore, New Zealand, and other countries with seasonal peaks in space heating/cooling demand, should urgently adjust policy settings to mandate highly energy-efficient housing for new-builds and retrofits in order to deliver a least cost low-carbon energy transition, which also captures the well-known social and health co-benefits of improved dwelling performance.