Energy performance assessment of semi-transparent photovoltaic integrated large-scale railway stations among various climates of China

Abstract

Semi-Transparent Photovoltaics (STPVs) have received increasing popularities as they conform to the architectural design trend of large-area glass curtain walls and expand the application scenes of building integrated photovoltaics (BIPVs). However, their high sensitivities toward extreme thermal and radiation climate conditions as well as the potential key integration scenario--skylights for large footprint buildings, have rarely been highlighted. Meanwhile, in context of the low energy glass application consensus as well as varieties of commercial module typologies with diverse photo-thermal-electrical properties, designers are still in lack of key understandings regarding actual energy performances and appropriate design solutions of STPV integrations upon diversed climate conditions. In this work, the actual energy-saving disparities, occasioned by distinct climate conditions of both thermal design and solar radiation resources, have been investigated in detail through simulation validations over representative large footprint railway station building prototypes. 14 representative cities covering most concerning climate zones, as well as seven STPV modules based on different PV technologies or featured photo-thermal-electrical properties had been examined for their climate responsivenesses. All engaged cities have been re-grouped from the new perspective into four categories (Low, Medium, High, Ultra-high energy-saving beneficial) with corresponding energy-saving rates (ESRs) (<15%, 14%∼20%, 20%∼22%, >24%) to reveal their true energy-saving beneficial potential levels. Design strategies on basis of applicable integration scenarios as well as appropriate module properties and typologies have been proposed corresponding to each reclassified city categories, to achieve the best conjugated energy-saving effects. This research can provide essential knowledge for finalizing STPV integration designs under the premise of a best energy-saving performance, in response to diversified and complicated climate conditions.