Why price per kWh is a poor way to compare storage

What this is about

The price per kilowatt-hour is the storage market’s favourite metric — and its most misleading one. It describes a purchase price per storage size, but says nothing about what the system delivers in operation.

What the kWh price hides

Two 200 kWh systems can differ by a factor of two in power — one shaves a 100 kW load peak, the other cannot. Add cycle life (5,500 vs. 8,000 cycles is a third more lifetime energy), round-trip efficiency (every lost percentage point costs money every single day), controllability (a closed system can do neither charging management nor dynamic tariffs), backup capability, and the question of who commissions and services the system.

The better comparison

A sound comparison calculates over the lifetime: usable energy across all cycles, valued against the actual applications from the load profile — self-consumption, peak shaving, e-mobility, backup reserve. Only then does it become clear which system is cheaper per kilowatt-hour actually used.

Comparison criteria

Criterion	System comparison	Price per kWh only
Power (kW)	assessed	ignored
Cycles & lifetime	assessed	ignored
Efficiency (RTE)	assessed	ignored
EMS / Modbus / STS	assessed	ignored
Service & commissioning	assessed	ignored

The Speichercampus verdict

The kWh price is only one metric. The decisive factors are power, EMS, STS, MPPT, Modbus, service, commissioning and the fit with the load profile.

Next step

Send us your load profile, electricity bill, PV data and project goal. Speichercampus assesses which storage capacity, power and product class make sense.

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