1System
2Usage
3Finance
4Advanced

System Cost & Incentives

Enter your installation quote and applicable incentives

$22,000

Total installer quote including panels, inverter, mounting, wiring, permits, and labor. Get at least 3 quotes.

$5K$80K
$
$0

Upfront rebate from your state or utility provider. Applied before the federal tax credit. Check dsireusa.org for your state.

$0$10K
$
30%

The Residential Clean Energy Credit is 30% through 2032, drops to 26% in 2033, 22% in 2034, then expires. Applied to net cost after state rebates.

0%30%
Net System Cost After Incentives
$15,400
$22,000 − $0 state rebate − $6,600 federal credit (30%)
8 kW

Total nameplate capacity of your solar array. Most residential systems are 5–12 kW. Divide annual kWh usage by ~1,200–1,500 to estimate required size.

2 kW30 kW

Energy Usage & Production

Your consumption and solar output estimates

10,500 kWh

Check your last 12 months of utility bills and add them up. US average is ~10,500 kWh/year. Add ~3,000 kWh if adding an EV.

3,00040,000
kWh/yr
$0.17/kWh

Find on your utility bill (total charges ÷ kWh used). US average is ~$0.16. CA/NY/MA often $0.22–$0.35. Higher rate = better solar ROI.

$0.06$0.55
$ /kWh
5.5 hrs/day

Annual average peak sun hours for your location. Phoenix: 6.5. Denver: 5.5. Los Angeles: 5.8. Chicago: 4.2. Seattle: 3.6. Boston: 4.5.

2.5 (Seattle)7.5 (Phoenix)
South (100%)

South-facing is optimal in the Northern Hemisphere. East/West loses ~15–20%. North-facing loses 25–30% vs. south.

North (70%)South (100%)
No shading (100%)

Trees or buildings blocking sunlight. No shade = 100%. Light morning/afternoon shade = 85–90%. Significant shading = 70–80%.

Heavy shade (60%)No shade (100%)
Estimated Year 1 Production
11,461 kWh
8 kW × 5.5 hrs × 365 × 100% orientation × 100% shading × 0.85 efficiency

Financing & Rate Assumptions

How you're paying and how rates will change

Cash maximizes ROI. Solar loans add interest cost but preserve capital. Leases/PPAs have no upfront cost but lower long-term return.

4.0%/yr

US average is ~3.5%/yr over 20 years. CA/NY/MA average 5–6%/yr. This is the most impactful variable — higher escalation dramatically improves solar ROI.

0% (flat)8%/yr
5.0%/yr

What your money would earn elsewhere. Use 4–5% for high-yield savings/bonds, 7–8% if comparing to stock market returns.

1%12%

Advanced Settings

Fine-tune for a more precise calculation

0.5%/yr

Tier-1 monocrystalline panels lose ~0.5%/yr. Budget panels 0.7–1%/yr. A 25-year warranty typically guarantees no more than 0.5% annual degradation.

0.1% (premium)1.5% (budget)
$2,500

String inverters typically need replacement in Year 12–15 ($2,000–$3,500). Microinverters last 25+ years but cost more upfront.

$0 (micro)$5,000
Year 13

When you expect to replace the string inverter. Typically Year 12–15. Subtract this cost from cumulative savings in that year.

Year 8Year 20
$0

Adding a home battery (e.g. Tesla Powerwall ~$10,000 installed). Critical in CA/states with reduced net metering export rates. Extends ROI timeline.

$0 (none)$25,000
Full retail (100%)

What your utility pays for excess solar exported to the grid. Most states: full retail rate (100%). CA NEM 3.0: ~25%. Some utilities: wholesale (~30–50%).

20% (wholesale)100% (full retail)
$15,000

National average home value premium for solar: ~$15,000 (Lawrence Berkeley Lab, 2024). Varies by market. Not taxable in most states.

$0$40,000