Annual energy at a supplier cost crossover calculator

Annual energy at equal total supplier cost is calculated as (F_new−F_old)/(r_old−r_new). Use the stated system boundary and matching input units.

E_{\text{cross}} = \frac{F_{\text{new}} - F_{\text{old}}}{r_{\text{old}} - r_{\text{new}}}

Calculator

Enter the values you know and leave one box empty. Calculate finds the empty one, the result or any input.

Given

E_{\text{cross}} = \frac{2400 - 600}{0.12 - 0.1} = 90{,}000

Symbol	Meaning	Unit
$E_{\text{cross}}$	annual energy at equal total supplier cost	kWh/year
$F_{\text{new}}$	new annual fixed supplier fee	$/year
$F_{\text{old}}$	old annual fixed supplier fee	$/year
$r_{\text{old}}$	old energy price	$/kWh
$r_{\text{new}}$	new energy price	$/kWh

Results are estimates for study and screening. Check the inputs, units and assumptions before you use them for design, billing or contract decisions.