MySunROI

What MySunROI actually calculates

Most solar websites hide the math behind a lead form. MySunROI is built the other way around: you get a transparent Solar Score™ — cash price, net cost after the 30% federal Investment Tax Credit (ITC), expected annual savings, and simple payback — before anyone asks for a phone number. The Volt Horizon interface is deliberately close to a field tool: inputs on top, outputs you can check against a written quote.

National midpoints in our model land near $16,271 for a typical 6 kW rooftop array, about $11,390 after the ITC, with rough annual bill savings near $1,335 and payback around 9 years. Those figures are education — not a bid. Your roof, utility rate plan, and installer overhead will move the answer.

How we model ROI and payback

Payback on MySunROI is simple payback: net system cost after the federal tax credit, divided by modeled first-year electricity savings. We intentionally keep the headline metric simple so you can reconcile it with a napkin check on any installer proposal. Behind that number, state pages use EIA retail electricity rates, NREL-style cost-per-watt benchmarks adjusted by regional modifiers, and peak-sun-hour assumptions so a Texas home and a New York home do not get the same generic “solar saves $150/month” claim.

First-year savings assume a grid-tied system sized near your usage, with production estimated from state sun hours and degraded only lightly in year one. We then show a 30-year savings band that layers modest rate inflation and panel degradation (~0.5%/year for tier-1 modules). That long-horizon number is for orientation — it is not a guarantee of utility policy, rate schedules, or inverter lifetime. Batteries are modeled as an optional add-on, not baked into default payback, because storage economics depend heavily on time-of-use rates and backup needs.

Federal tax credit (2026) in the net-cost step

The calculator subtracts the residential federal ITC — currently 30% of qualified solar (and, when eligible, battery) costs — to produce net cash cost. You still need taxable liability to monetize the credit in the year you place the system in service; unused credit can typically carry forward. MySunROI does not prepare tax returns. Read the dedicated 2026 ITC guide and confirm eligibility with a tax professional before you treat net cost as “money already in hand.”

What changes the answer between states

Two homes with identical roofs can see very different ROI. High retail rates (California territories, parts of the Northeast) accelerate payback even when installed $/W is higher. Strong sun and lower installation overhead in markets like Texas or Arizona help production but may face weaker export credits if your retail electric provider pays wholesale for surplus kWh. Net metering and buyback rules matter as much as panel brand. Our net metering guide and state cost pages flag the policy frame; topic pages on incentives and payback stay available for browsing but are treated as secondary templates, not the primary indexable corpus.

• Cost per watt ($/W) before incentives — the honest quote comparison metric
• Your utility’s export / net-metering credit rate, not just retail cents/kWh
• Shade, azimuth, and usable roof area (production, not nameplate kW, pays the bill)
• Loan dealer fees and escalators — they can erase “$0 down” marketing wins
• Whether a battery is solving TOU peak or marketing fear of outages

How to use the calculator without getting sold

1. Enter your state (or nearby metro) and a realistic monthly kWh or bill estimate.
2. Note gross price, ITC-adjusted net cost, and simple payback — screenshot or write them down.
3. Collect three itemized cash quotes and normalize each to $/W with our quote comparison tool.
4. Stress-test optimistic production claims against your state’s sun hours and shading — if a quote pays back in four years in a cloudy northern market with average rates, ask for the model assumptions in writing.
5. Only then open financing paperwork. Compare loan APR and dealer fees to a cash/HELOC path using financing options and lease vs buy.

Methodology, sources, and editorial limits

State midpoints start from public NREL photovoltaic cost benchmarks and EIA residential rate series, then apply MySunROI regional modifiers for labor and soft costs. We refresh the model when federal incentive rules or major rate benchmarks shift; last site-wide review: 2026-07-15. Figures are educational ranges for homeowners researching purchase decisions — not engineering stamped designs, interconnection guarantees, or tax advice. Full sourcing notes live on our data sources page and editorial policy.

MySunROI does not install solar and does not take a cut of your equipment choice. Advertising and optional quote referrals never rewrite the math on this page. If a salesperson’s spreadsheet disagrees with your Solar Score™ by more than ~15% on net cost or annual kWh, ask which inputs drove the gap — rate, production factor, or incentives — before you sign.