This tool estimates your return on investment by calculating annual energy production
using the formula: System Size (kW) × Daily Sun Hours × 365 days × 0.75 efficiency.
That production figure is multiplied by your electricity rate to find annual savings,
which are then compared against your total installation cost to determine payback period.
Our CO₂ offset data uses 0.4 kg CO₂ per kWh based on 2026 EPA greenhouse gas equivalency factors. Tree equivalents use the EPA's estimate of approximately 22 kg of CO₂ sequestered per tree per year.
Federal tax credit notice: The 30% residential solar tax credit (Section 25D) expired December 31, 2025 under the One Big Beautiful Bill Act. This calculator reflects pre-incentive costs. Many states offer their own credits and rebates — see the full calculator for details.
Disclaimer: All figures are estimates. Actual ROI depends on local shading conditions, equipment brand and quality, installation quality, utility net metering policies, and ongoing maintenance.