The spatial and temporal mismatch phenomenon in solar space heating applications: status and solutions

Building space heating has led to tremendous energy consumption globally. The mismatch between fluctuating solar energy resources and stochastic space heating load shall be solved to realize the transition from fossil energy to solar energy for space heating. In the spatial aspect, the discrepancy of solar energy resources in different regions is considerable and the heating load is also varying with the climate type, population density, and so on. In the temporal aspect, the seasonal and diurnal solar energy resource usually has an opposite trend to the actual space heating demand. The spatial and temporal mismatch between solar energy and heating load cause inefficient solar energy utilization and prejudice the decarbonization goal. This work is focused on the status and solutions to this phenomenon, and the state-of-art from the perspective of both the supplement and demand sides are reviewed, as well as the extensive policy outlook for mitigating the mismatch problem in solar space heating applications. Finally, the future investigation suggestions and research gaps on this scientific problem are concluded from this work.