Start with your electricity bill—not a seller package size.

A peso bill is useful, but the kWh on the bill is better.

Your peso amount depends on the effective electricity rate, while solar sizing starts from energy use. If you only know the peso amount, Solar Plan Lab can use a visible starting rate assumption for the first estimate and let you replace it later with the bill's actual kWh or effective rate.

• Use a normal month rather than the highest bill you have ever seen.
• Three or more months are better when usage changes with weather or occupancy.
• Battery size should be based on the backup goal and essential loads, not the peso bill alone.