RTE
RTE in the SpeicherCampus context: the overall efficiency across charging and discharging. Technically, the term is usually described as Round Trip Efficiency.
What does RTE mean?
Round Trip Efficiency is the overall efficiency across the full cycle: how much of the energy charged comes back out on discharge? An RTE of 90 % means: of 100 kWh stored, 90 are usable — 10 are lost to conversion, battery and auxiliary consumption.
RTE acts directly on the economics, because every cycle pays for the losses: with daily cycling, a few percentage points add up to substantial energy over 15 years.
What matters in practice
- clarify the system boundary of the figure: with or without cooling and standby?
- compare AC-to-AC RTE, not battery DC values against system values
- watch part-load behaviour: efficiency drops at low power
- auxiliary consumption (cooling!) belongs in the honest balance
Practical example
Two systems advertise “up to 94 %” and “87 %”. The first measures DC-side without cooling, the second complete AC-to-AC. At the same system boundary both sit around 87 % — the apparent difference was a measurement-boundary question.
The SpeicherCampus perspective
SpeicherCampus compares RTE figures only at identical system boundaries and includes the losses explicitly in the economic analysis.