A new residential system prices at $2.50–$3.75 per watt before any add-ons, adjusted for panel type and roof/mounting difficulty. A 6 kW polycrystalline system on a tile roof, for example, prices at roughly $16,100–$24,200 for the array alone — tile's steeper flashing work adds about 22% over asphalt. Battery storage, an EV charger circuit, and a panel upgrade are priced separately on top.
How the price builds, in order
This calculator starts from a base cost of $2.50–$3.75 per watt for the system size you pick (4–12 kW), then multiplies twice: once for panel type — monocrystalline at 1.0×, polycrystalline at 0.88×, thin-film at 0.82× — and once for roof or mounting type, where asphalt is the 1.0× baseline, metal adds 5%, ground-mount adds 18%, and tile adds the most at 22%, reflecting the extra flashing and tile-hook labor a tile roof requires.
Estimated annual production is a flat national-average assumption of 1,300 kWh per installed kW — a 6 kW system produces about 7,800 kWh a year, which this tool values at a blended $0.16/kWh retail rate (±15% for regional variation) to estimate the electricity it offsets, not to promise actual utility savings.
No federal credit is built into this number
Every total on this page is pre-incentive. The federal residential credit that used to return 30% of a system's cost, Section 25D, is not available for property placed in service after December 31, 2025, so a 2026 installation does not get to subtract anything federal from the figures above. Use the federal solar tax credit calculator to check whether a state, local, or utility incentive still applies in your area, and layer that on separately.
Methodology
Base rate, panel-type and roof-type multipliers, and add-on ranges (battery, EV charger circuit, panel upgrade) are the literal constants in this calculator's own module. Production is a flat 1,300 kWh/kW/year national-average assumption valued at a blended $0.16/kWh. The federal-credit exclusion follows the IRS residential credit expiry below.
Sources
- IRS — Residential Clean Energy Credit (Section 25D) — accessed 2026-09-05