Power Inverter Efficiency
Power Inverter Efficiency
A power inverter converts DC power to AC (or vice versa), and no real conversion is lossless — some input power is always dissipated as heat in the switching devices and magnetics. Efficiency, the ratio of usable output power to input power, is the standard figure of merit for comparing inverters.Even a few percentage points of efficiency difference matters at scale: in a solar or battery system running continuously, lower inverter efficiency means more energy lost to heat every single day, which adds up to real money and reduced system capacity over the inverter’s lifetime.
The efficiency is η = P_out/P_in, the output power divided by the input power. where P_out is the inverter’s delivered output power and P_in is the power drawn at its input.
Inputs
P_out := 950 W=950 W
P_in := 1000 W=1000 W
Dividing the delivered output power by the power drawn at the input gives the fraction of power that made it through the conversion process without being lost.
eta_inv2 := P_out/P_in=0.95
Results
An efficiency of 0.95 (95%) is a good, realistic figure for a modern inverter operating near its rated load — most quality inverters achieve 90–97% efficiency at typical loading. Efficiency generally drops off at very low or very high loading relative to the inverter’s rated capacity, so this single-point figure should ideally be checked across the expected operating range, not just at one load level.
Assumptions & limitations
- Efficiency measured at a single operating point; it varies with load level.
- Steady-state operation; startup and standby losses not included.
- Input and output power measured at the same time under matched conditions.