Calculator
← All Tools
BriskDeck / Solar ROI Calculator

Solar Panel ROI Calculator

Calculate payback period, 25-year savings, and environmental impact by state.

Your solar setup
8 kW
16¢
3.0%

25-year cumulative savings
Key insights
Environmental impact
Disclaimer: Estimates based on NREL solar data, EIA electricity rates, and 30% federal tax credit. Actual savings vary by installation specifics, shading, and utility policies.

How to Use This Calculator

  1. Select your state — Electricity rates and solar incentives vary dramatically. California (32¢/kWh) offers much faster ROI than Washington (11¢/kWh).
  2. Choose system size — 4-12 kW covers most homes. A typical 8 kW system produces ~10,000-14,000 kWh per year.
  3. Adjust electricity rate — Override with your actual rate from your utility bill for more accurate results.
  4. Set annual increase — Historical US electricity prices rise ~3% annually. Higher increases mean faster solar payback.
  5. Select financing — Cash purchase maximizes ROI. Solar loans spread costs but reduce net savings.

Solar ROI by State

StateRate (¢/kWh)Sun Hours/DayPayback25-Year Savings
California325.55 yr$55,000+
Arizona136.07 yr$28,000+
Massachusetts274.06 yr$40,000+
Texas145.08 yr$25,000+
US Average164.57 yr$30,000+

Key Factors That Affect Solar ROI

☀️ Sun exposure

More sun = more production. Arizona (6 hrs/day) generates 70% more than Washington (3.5 hrs/day) with the same panels.

💰 Electricity rates

The higher your local rate, the more you save. California homeowners save 2-3x more than those in low-rate states.

🏛️ Federal tax credit

The 30% federal ITC reduces your net system cost by nearly a third. On a $20,000 system, that's $6,000 in tax savings.

📈 Rate increases

US electricity prices have risen ~3% annually for decades. Solar locks in your energy cost, protecting against future hikes.

Frequently Asked Questions

How long do solar panels last?

Most solar panels come with a 25-year performance warranty and continue producing at 80-90% capacity beyond that. The inverter may need replacement at 10-15 years ($1,000-$2,000).

Do solar panels work on cloudy days?

Yes, but at reduced output — typically 10-25% of peak capacity. Our calculator uses average annual sun hours that already account for cloudy days, so results reflect real-world performance.

What size solar system do I need?

A typical US home needs 6-10 kW to cover 100% of electricity usage. Check your annual kWh usage on your utility bill — each kW of solar produces roughly 1,200-1,800 kWh per year depending on location.

Is solar worth it without the tax credit?

In high-rate states like California and Massachusetts, solar can still pay off without incentives — the payback just extends 2-3 years. In low-rate states, the tax credit is often what makes solar financially viable.