Background: Zhejiang Province implements a time-of-use electricity tariff, with a peak-valley price difference of approximately RMB 0.6–0.8/kWh. Residential electricity follows a tiered pricing structure, with the third tier having the highest rate.
User Profile: A city villa with an existing 8kW rooftop PV system. The household consumes about 800kWh per month (higher in winter/summer due to air conditioning and underfloor heating).
Pain Points: High electricity consumption from air conditioning in summer and underfloor heating in winter frequently pushes the household into the expensive third-tier electricity rate. The goal is to reduce overall electricity costs.
Solution:
1、Configuration: 15kWh residential energy storage + 6kW hybrid inverter
2、Strategy: Charge from the grid during off-peak hours (nighttime) and discharge during peak hours (daytime) to supplement household loads. Surplus PV power is prioritized for battery storage.
Results:
1、Annual electricity savings of approximately RMB 8,000
2、Avoids falling into the third-tier electricity rate
3、Payback period of approximately 5–6 years
