Residential PV-BES systems: Economic and grid impact analysis

The energy industry has seen a revolutionary transformation in the growth of renewables over the past decade. With recent advances in battery storage performance, solar energy is fast becoming the focus of the global energy shift towards a more sustainable future. Photovoltaic (PV) systems integrated with Battery Energy Storage (BES) systems are expected to play an important role in the UK’s future energy industry, aided in part by manufacturing cost reductions. For energy consumers, these systems can deliver considerable savings in utility costs and potentially bring a financial return via a feed-in-tariff (FIT) scheme. Such a system could also help energy suppliers and network operators ease the burden of a huge surge of future energy demand, mitigate network congestion and improve system resilience and autonomy. There is, however, limited literature that utilises simulation to investigate the influence of PV-BES system deployment at urban scale on the grid based on economic and technical analysis. In this work, a household-level model is developed that includes load demand heterogeneities, as well as BES and PV systems. The single household model can be scaled to higher levels, such as streets and community, hence the model can be applied to study the interaction between households, the wider community and the grid, in terms of electricity im/export, BES usage and network injection impact. A comprehensive analysis of both technical and economic perspectives is presented based on several key performance indicators (KPIs), such as self-consumption rate (SCR), self-sufficiency rate (SSR) and reduction in peak charges. The addition of a BES system can significantly increase the self-consumption of a home PV system, by at least 15%, however the expensive upfront cost of the BES system leads to a much longer payback time.