Techno-economic assessment of battery systems in the PV self-consumption without surpluses in the residential tariff of the Dominican Republic

This study develops a techno-economic model to evaluate the feasibility of battery energy storage systems (BESS) integrated into photovoltaic (PV) self-consumption schemes without surplus injection under the Dominican Republic's residential tariff. Hourly consumption data from three real households were analyzed, defining three representative demand levels—low, medium, and high. System sizing was optimized by maximizing net present value (NPV) while assessing internal rate of return (IRR), self-consumption ratio (SCR), self-sufficiency ratio (SSR), levelized cost of energy (LCOE), and a proposed parity index (PI). Results indicate that PV self-consumption is profitable only for high-demand users (≥ 701 kWh month −1 ), achieving grid parity (PI ≈ 1.0; IRR ≈ 10 %). Battery integration raises SCR from 73.4 to 98.3 % and SSR from 34 to 45 %, however reduces profitability because of higher capital investment. Profitability is highly sensitive to the hourly demand profile: redistributing identical daily consumption improved NPV by up to 16 %. Removing the residential subsidy slightly enhances profitability for low- and medium-demand users, while high-demand users lose competitiveness. A 30 % reduction in battery cost increases NPV by 18 % for high-demand profiles but remains insufficient for others. These results confirm that PV + BESS are technically and economically viable for high-demand consumers, strengthening energy autonomy and resilience in countries with similar tariffs and solar resources. • Develops a techno-economic model for PV + BESS non-export self-consumption systems • Finds PV self-consumption viable only for high-demand users (≥ 701 kWh month −1 ) • Integrating BESS raises SCR by 25 % and SSR by 11 % but reduces profitability • Profitability strongly depends on the hourly match between demand and generation • Proposes a parity index (PI) transferable to emerging economies with similar tariffs