Preparation for an energy positive community in the UK: modelling-led innovative housing practice in Wales

This paper presents a modelling-led approach to low carbon innovative housing, including a new build and five retrofits located in Wales. The research aims to investigate the implementation of combinations of existing and emerging low carbon technologies through a systems based approach to optimise the use of energy at the point of generation. A performance prediction model has been developed to examine the effectiveness of different strategies in relation to energy and carbon reduction. Simulation results for the new build show the potential to limit energy imported from the grid to about 25% with an annual export to import ratio of 1.55, providing an energy positive performance. For the retrofit properties, the application of Photovoltaics (PV) and LED lighting can reduce the total electricity demand from the grid by up to 90%, and the combination of reduced energy demand, renewable energy supply and battery storage has been shown to reduce net carbon emissions by up to 110%, with total financial savings of 90%-190% through reduced operating energy cost and earnings from renewable energy generation and export. Gas heating energy for the retrofits has been reduced by 20% to 80%. The new build ‘energy positive’, and retrofit ‘nearly-zero energy’, performances can be achieved through an integrative ‘systems’ based approach. This includes attention to affordability and replicability. A grid connection is still needed to balance across seasonal demand and renewable supply, however, the pressure on the grid to provide energy is reduced.