The nature of combining energy storage applications for residential battery technology

Batteries are expected to play an important role in the transition to decarbonised energy systems by enabling the further penetration of renewable energy technologies while assuring grid stability. However, their hitherto high capital costs is a key barrier for their further deployment. In order to improve their economic viability, batteries could provide several applications offering revenues. The techno-economic evaluation of batteries simultaneously serving several applications has proven to be challenging due to the trade-offs between energy and power applications. Focusing on residential batteries, we develop an optimisation method for designing optimal value propositions and we test it for four different applications both individually and jointly: PV self-consumption, demand load-shifting, avoidance of PV curtailment and demand peak shaving. Our results show that the combination of all applications currently helps batteries to get closer to profitability, from a net present value (NPV) per unit of capital expenditure (CAPEX) of -0.63 +/- 0.04 for PV self-consumption only to -0.36 +/- 0.10, with the combination of demand peak-shaving and PV self-consumption adding most value (0.21 +/- 0.04). We also find that the annual household's electricity consumption determines the value of energy storage applications. The proposed method allow us to classify storage applications as complementary and substitutive depending on whether their combined application increases their economic attractiveness or not. These results thus offer valuable insight for stakeholders interested in the deployment of energy storage in combination with energy efficiency, heat pumps and electric vehicles such as consumers, utility companies and policy makers.