Home Solar Atlas
Free planning tool

Home Solar Calculator

Enter your ZIP code and electricity use to estimate a system using location-specific PVWatts V8 solar production, current state electricity data and adjustable financial assumptions.

Enter ZIP for location-specific PVWatts solar production.
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¢/kWh
EIA 2026 YTD state average loaded automatically. Edit it if your utility rate is different.
Advanced assumptions
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Annual usage is estimated from your bill and electricity rate. With a valid ZIP, production is modeled using NLR PVWatts V8; otherwise the calculator uses a state-level planning factor.

Local energy data

Utility & Incentives by ZIP

Find nearby residential utility plans, distributed-generation rules and active solar incentives before we model the tariff in the savings engine.

2026 incentive handling

No expired federal homeowner credit is hidden in the calculator

The installed solar cost used by this calculator is the system size multiplied by the cost-per-watt assumption, plus the optional battery planning allowance. Home Solar Atlas does not silently multiply a new 2026 project by 70% or automatically subtract the former Section 25D Residential Clean Energy Credit.

State, local and utility incentives can still matter. Research them separately and include only benefits you have verified for your project when making a final household payback decision.

Read the Federal Solar Tax Credit in 2026 guide →Search state and utility incentives →Run a detailed 25-year payback model →

How Calculator v3 works

  • A valid U.S. ZIP code is converted to approximate latitude and longitude using postal-code location data.
  • Those coordinates, roof tilt and direction are sent server-side to National Laboratory of the Rockies PVWatts V8 to estimate production for a 1 kW reference system.
  • The returned kWh-per-kW yield is used to size your system for the selected percentage of annual electricity use.
  • Residential electricity prices start with U.S. EIA Electric Power Monthly, Table 5.6.B, Year-to-date through June 2026, and remain editable because individual utility tariffs vary.
  • The local-data module queries OpenEI's U.S. Utility Rate Database for nearby residential tariffs and OpenEI for active residential renewable-energy incentives.
  • Complex utility tariffs are shown as reference data first. We do not automatically replace the calculator's all-in electricity rate until the tariff engine can model TOU, tiers, fixed charges and export compensation correctly.
  • If PVWatts, OpenEI or ZIP lookup is unavailable, the core calculator automatically falls back to our state-level planning data instead of failing.
NLR PVWatts V8 documentation ↗OpenEI utility-rate documentation ↗EIA electricity-rate source ↗