How much energy do you use?
Power tells you the rate. Time tells you the amount. Change your assumptions and follow the balance.
ENERGY BALANCEConstant-power model
INPUT ENERGY
90kWh
1.500 W × 2 h × 30 días ÷ 1.000
Useful energyOther transfers
Variable cost18,00 €
Useful energy72 kWh
Other transfers18 kWh
How the model works
E = P × t / 1.000
C = E × precio
Eútil = E × η
C = E × precio
Eútil = E × η
P is entered in watts, t is the total number of hours and E is in kWh. The useful fraction depends on the service being considered; energy is transformed, not lost.
Explore related conceptsWhat is not included
Power is assumed constant during use. Cycling, temperature control and standby require actual profiles or measurements. Cost includes only the energy charge, excluding capacity charges, fixed fees, taxes and time-of-use rates. No emissions or geographic factors are estimated.
Reference: U.S. Department of Energy · Estimating Appliance and Home Electronic Energy Use