Correct sizing starts with twelve months of kilowatt-hour usage, not with square footage and not with a single summer bill.
The inputs that matter
Annual kWh usage, your rate schedule, roof orientation and tilt, shading through the year, and any load you expect to add — an EV, a heat pump, a pool, a workshop.
Oversizing and undersizing
Undersizing leaves you paying peak rates for the remainder. Oversizing past your usage produces exports valued below what you pay to import. There is a right band for each home, and finding it is the point of the analysis.
Related services
Solar production, bill offset and payment comparisons vary by home, usage, roof, shading, utility rate schedule and financing terms. Nothing on this site is a guarantee of savings. Pricing comparisons depend on system size, equipment, financing structure and contract terms. Any comparison is only meaningful between comparable systems and comparable financing.