ROI Comparison Tool
Pick your state and a kit to see a personalized 25-year savings projection — including the payback year, annual savings growth as rates rise, and your net profit over the system's lifetime.
Your setup
$0.310/kWh · 5.5h sun · 5.0%/yr escalation
65%
30% (low)100% (battery)
How much of your generation you actually use. Higher if you have a battery or are home during the day. Learn more →
Payback
Year 4
break-even point
Year 1 savings
$279
898 kWh offset
10-year total
$3.4k
cumulative savings
25-year total
$12.4k
$11.4k net profit
Cumulative savings — 25-year projection
savings cost
Based on California's $0.310/kWh rate, 5.5h/day sun,5.0%/yr rate escalation, 65% self-consumption, 0.5%/yr panel degradation.
Year-by-year breakdown
| Year | kWh offset | Rate/kWh | Annual savings | Cumulative | vs. cost |
|---|---|---|---|---|---|
| 1 | 898 | $0.310 | $279 | $279 | -$690 |
| 2 | 894 | $0.326 | $291 | $569 | -$400 |
| 3 | 889 | $0.342 | $304 | $873 | -$96 |
| 4✓ | 885 | $0.359 | $318 | $1,191 | +$222 |
| 5 | 881 | $0.377 | $332 | $1,523 | +$554 |
| 6 | 876 | $0.396 | $347 | $1,870 | +$901 |
| 7 | 872 | $0.415 | $362 | $2,232 | +$1.3k |
| 8 | 867 | $0.436 | $378 | $2,610 | +$1.6k |
| 9 | 863 | $0.458 | $395 | $3,005 | +$2.0k |
| 10 | 859 | $0.481 | $413 | $3,418 | +$2.4k |
| 11 | 854 | $0.505 | $431 | $3,850 | +$2.9k |
| 12 | 850 | $0.530 | $451 | $4,301 | +$3.3k |
| 13 | 846 | $0.557 | $471 | $4,772 | +$3.8k |
| 14 | 842 | $0.585 | $492 | $5,264 | +$4.3k |
| 15 | 838 | $0.614 | $514 | $5,778 | +$4.8k |
| 16 | 833 | $0.644 | $537 | $6,315 | +$5.3k |
| 17 | 829 | $0.677 | $561 | $6,876 | +$5.9k |
| 18 | 825 | $0.711 | $586 | $7,462 | +$6.5k |
| 19 | 821 | $0.746 | $612 | $8,074 | +$7.1k |
| 20 | 817 | $0.783 | $640 | $8,714 | +$7.7k |
| 21 | 813 | $0.823 | $668 | $9,383 | +$8.4k |
| 22 | 809 | $0.864 | $698 | $10,081 | +$9.1k |
| 23 | 805 | $0.907 | $730 | $10,811 | +$9.8k |
| 24 | 801 | $0.952 | $762 | $11,573 | +$10.6k |
| 25 | 797 | $1.000 | $796 | $12,369 | +$11.4k |
Projections are estimates for planning purposes. Actual savings depend on your usage patterns, local utility rates, and weather. Affiliate disclosure · About self-consumption