• STPV-integrated greenhouses improved tomato yields while maintaining plant health. • 69% transparent c-Si STPV achieved the highest and most consistent yield gain (+38%). • Heat pump retrofits eliminated gas use with only 1.5 × higher electricity demand. • Agrivoltaic STPV supplied 13% of annual electricity with minimal lighting penalties. • Combined STPV-heat pump cut CO2e emissions by 71.7% in cold-climate greenhouses. In agrivoltaic controlled environmental agriculture, semi-transparent photovoltaic (STPV) modules are incorporated into greenhouses to provide sustainable energy for operations. For the first time, this study evaluates the performance of STPV technologies integrated into tomato greenhouses in southern Ontario through experimental agronomic investigations and three energy, economic, and environmental simulation scenarios: i) conventional gas-heated, ii) heat pump-based, and iii) agrivoltaic-heat pump-based greenhouses. STPV configurations tested included crystal silicon with 44% and 69% transparency, as well as with luminescent solar concentrators (53% and 69% transparency), and red and blue thin-film (50% transparency). The agrivoltaic systems maintained stable leaf chlorophyll content and comparable growth trends relative to the control, however 69% transparent crystal silicon PV improved yield the best by 38%. EnergyPlus modeling results indicated while heating loads were nearly three times higher than cooling loads, replacing the gas heater with a heat pump fully eliminated fossil fuel consumption, and increased electricity use by only about 1.5 times. Integrating the selected 69% STPV system with a heat pump enabled fully electrification of an agrivoltaic greenhouse. The agrivoltaic system supplied approximately 13% of the total annual electricity demand. Although this increased costs 5% relative to subsidized gas, the costs were stabilized and the carbon emissions were reduced by 71.7%, outperforming the heat-pump-only retrofit with 67.9% reductions. Overall, the results demonstrated that rooftop agrivoltaic integration combined with heat pump electrification is a technically feasible and environmentally effective pathway toward low-carbon greenhouse operation in northern climates like Canada.
Asgari et al. (Wed,) studied this question.