Solar Panel ROI Calculator
Calculate solar payback period, 25-year savings, and ROI including the 30% federal tax credit, state rebates, and utility rate increases.
System details
System size (kW)
kW
Avg home: 6–10 kW
Cost per watt installed
$
2024 avg: $2.50–$3.50/W
Annual electricity use
kWh
US avg: ~10,500 kWh/yr
Location & utility rate
National average avg rate: $0.16/kWh · 4.5 avg daily sun hours
Incentives & rebates
Federal ITC (30%)
$7,200
Applied automatically
State rebate / credit
$
Check dsireusa.org
Utility rebate
$
Assumptions
Annual rate increase
%/yr
US hist. avg ~3%
Panel degradation
%/yr
Industry avg 0.5%/yr
Financing
Payback period
9 yrs
Net cost after incentives: $16,800
25-year net savings
+$41,964
$58,764 savings − $16,800 cost
Gross cost
$24,000
Federal credit
$7,200
Net cost
$16,800
Year 1 savings
$1,680
Annual production
10,512 kWh
Offset percentage
100%
System ROI (25yr)
250%
Savings projection
| Year | Annual savings | Cumulative | Net benefit |
|---|---|---|---|
| Year 1 | $1,724 | $1,724 | $-15,076 |
| Year 5 | $1,902 | $9,058 | $-7,742 |
| Year 10 | $2,150 | $19,298 | +$2,498 |
| Year 15 | $2,431 | $30,876 | +$14,076 |
| Year 20 | $2,748 | $43,965 | +$27,165 |
| Year 25 | $3,107 | $58,764 | +$41,964 |
| Year 30 | $3,512 | $75,495 | +$58,695 |
Getting the best solar deal
Get quotes from at least 3 installers — prices vary 20–30%. The federal ITC is 30% through 2032, then steps down. Check dsireusa.org for state incentives. Avoid 25-year solar loans — interest often exceeds the benefit. Net metering policies vary by utility — confirm how excess power is compensated before committing.
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