Choice of Domestic Air-Sourced Solar Photovoltaic Thermal Systems through the Operational Energy Cost Implications in Scotland

In Scotland, homebuilders are requested to take valiant efforts to meet the government’s ambition that all newly built homes should be carbon-neutral by 2016/17. In delivering net zero carbon homes, the application of renewable energy technologies, such as solar photovoltaic (PV) power generating systems, is almost inevitable. Costeffectiveness of emerging green technologies is a major factor that affects stakeholders’ housing design decision-making on whether or not the innovations can be applied in practical terms. Based on the United Kingdom (UK) government’s Standard Assessment Procedure (SAP) for energy rating of dwellings, this study conducted a comparative value assessment of 19 design alternatives set. The options also included ones that encompassed both electricity and heat generation potentials of PV applications—i.e., air-sourced PV thermal (PV/T) systems. Based on the SAP simulation results, it concluded that operational energy use and cost, as well as carbon dioxide (CO2) emission levels, can drastically be reduced particularly when a PV/T system is combined with a low-energy and highperformance mechanical ventilation with heat recovery (MVHR) system that can extract fresh air heated by PV. This study led to visualizing the cost-effectiveness of PV/T MVHR systems and identifying the economic value over 10 years at the interest rate of 10%, based on an assumption that the innovations are applied to Scottish homes today.