Theoretical study of building-integrated photovoltaics based on perovskite single junction and perovskite/silicon tandem solar cells:

Considering the perovskite-based building-integrated photovoltaics, we use the single box model of 4 x 4 x 3 m(3) to illustrate a promising solution for the zero-energy residential building and the distributed power generators in the Wuhan urban area in China (N30 degrees E114 degrees), where we have the high ratio of facades on the tall buildings. According to our estimation, the energy gains from the solar cells on the facades could be competitive with the ones on the rooftops. In comparison with the perovskite/silicon tandem solar cells, the perovskite-based single-junction solar cells could boost the annual energy gains more than 1.5 times on the facades. It is because of the perovskite-based single-junction solar cells being less angle-dependent, even if their efficiencies under the vertical illumination are lower than that of the perovskite/silicon tandem solar cells. Within the same single box, the energy demands caused by the air-conditioning system are simulated by the program THERB with 100 and 65% solar irradiation; the previous one is the standard case, and the later one assumes that 35% of solar irradiation is converted to the electricity. To control the indoor temperature above 18 degrees C in winter and below 26 degrees C in summer, the single box could achieve zero-energy demand except for January and December. And the annual surplus photovoltaic energy gains of 3071 kW h could be used as the distributed generator for the resident downstairs.