kW and kWh
kW and kWh in the SpeicherCampus context: kW describes instantaneous power, kWh the amount of stored or consumed energy. Technically, the term is usually described as power and energy.
What do kW and kWh mean?
Kilowatts (kW) measure power — what flows in a given moment. Kilowatt-hours (kWh) measure energy — what accumulates over time. A system with 105 kW and 215 kWh can therefore deliver at most 105 kW at once, and sustain that for roughly two hours.
Confusing the two is the most common planning mistake in the storage market. Capacity answers “for how long?”, power answers “how much at once?” — and depending on the application, one or the other dominates.
What matters in practice
- peak shaving mainly needs kW; self-consumption shifting mainly needs kWh
- backup power needs both: power for the loads, energy for the duration
- the kW/kWh ratio (C-rate) must fit the application
- only compare offers when both figures are stated
Practical example
Two offers: 200 kWh/50 kW and 200 kWh/100 kW. For pure PV shifting they are equivalent. For the business’s 90 kW load peak, only the second is usable — at identical capacity.
The SpeicherCampus perspective
SpeicherCampus derives both figures from the load profile: power from the peaks, capacity from PV surplus, charging windows and the desired bridging time.