"Photovoltaic+Energy Storage": Analysis of the Impact on Household Users and Economic and Environmental Benefits after Large-scale Integration to Distribution Network

Abstract

Driven by the carbon peaking and carbon neutrality goals, distributed photovoltaic (PV) systems with energy storage are transitioning from demonstration projects to large-scale deployment. However, the mechanisms underlying their impact on household users and system-level economic-environmental benefits remain unclear. This study breaks through the conventional unidirectional “generation-grid-load” analysis paradigm by constructing a “generation-grid-load-storage” coordinated optimization model. It pioneers the application of Contingent Valuation Methodology (CVM) to household energy storage investment decisions, quantifying the endogenous impact of behavioral variations on economic viability. Using 1,000 households in high-irradiance City A and medium-to-low-irradiance City B as samples, four scenarios were designed for comparative analysis. Results indicate: 1) All “PV+storage” solutions yielded positive net present values (NPV). However, demand response is key to unlocking storage value, nearly doubling NPV in low-irradiance areas and reducing payback periods by 4 years; 2) The cost-benefit analysis of system-level expansion shows that the external benefits brought by demand response and delaying power grid expansion account for 33% of the total benefits, which is significantly higher than the traditional assessment of saving electricity;3) The payback period for the household system can be shortened by about 0.7–1 years if a carbon inclusive mechanism is incorporated, given its average annual CO₂ emission reduction of 3–5 tons; 4) Households with high incomes and strong environmental awareness demonstrate an average 30% higher willingness to pay (WTP) for energy storage solutions. Targeted subsidies prove over 20% more effective than blanket subsidies. This research provides quantitative evidence for designing differentiated policies, market mechanisms, and carbon credit programs in regions with high distributed energy grid integration.