A commercial customer in Switzerland has deployed a 250kW/522kWh energy storage system (ESS) alongside an existing solar PV system to improve solar self-consumption and optimize energy use. The project addresses a common challenge in C&I solar energy storage: peak PV generation does not always coincide with the facility’s electricity demand, leaving surplus solar energy with lower economic value.

In this project, grid electricity costs around CHF 0.26/kWh, while surplus solar power can be exported at approximately CHF 0.09/kWh. As a result, excess PV generation during the day could have relatively low value, while electricity may need to be purchased from the grid later at a higher cost. To address this mismatch, the customer selected a 250kW/522kWh energy storage system (ESS).

The operating strategy is straightforward: PV first supplies local loads → surplus solar charges the battery → stored energy is discharged during higher-value periods. With a grid-tied configuration, the stored energy can also be exported to the grid when market conditions are favorable.

Rather than generating more solar power, the ESS helps shift energy from lower-value periods to higher-value periods, increasing solar self-consumption and improving overall energy utilization.

Based on the local electricity tariffs, PV generation, load profile, and operating strategy, the project has an estimated 4–5-year payback period under the self-consumption optimization mode.

This case demonstrates how C&I energy storage can help businesses move beyond simply generating renewable energy toward using every kilowatt-hour where it creates greater value.