The global carbon dioxide emissions from fossil fuels continue to rise, driven by rising energy use. Rooftop photovoltaic (RTPV) systems are an effective way to reduce emissions and, consequently, the carbon footprint for residential consumers. The use of behind-the-metre (BTM) energy storage with RTPV is a flexible and dependable method for generating electricity as it provides power to the customer even if there is an outage from the utility grid. It also reduces reliance on the utility through savings in the electricity bill and reducing CO2 emissions. In this paper, we analyse the economics and emissions along with the sizing of BTM battery storage co-located with RTPV for residential customers in India. Based on the power flow interactions between RTPV, grid, and battery storage, a techno-economic framework is built to compute the system’s life cycle cost. The life cycle cost of energy for BTM battery storage with RTPV to meet a 14 kWh energy demand is INR 11/kWh. We observe a 75% decrease in utility costs and a 58% reduction in CO2 emissions for the same system. The findings of this study can help policymakers, utilities, and homeowners make informed decisions regarding the adoption and integration of energy storage systems with residential solar PV installations.
