Solar in Washington, DC: 2026 Cost, Savings & Payback
Calculate 2026 solar panel cost, payback, and 25-year bill savings in Washington, District of Columbia. Based on an estimated 4.6 peak sun hours/day, a 13.6¢/kWh planning electricity rate, Pepco (Potomac Electric) as the likely utility, and current IRS guidance for the ended federal residential clean energy credit.
Solar in Washington, DC: quick answer
A typical 6kW solar system in Washington costs about $17,400 before local or state incentives. For 2026 installs, the federal residential clean energy credit is modeled as $0, so the estimated cost remains about $17,400 before any local incentive. It produces about 8,059 kWh per year from 4.6 peak sun hours/day, saves about $1,094 per year, and reaches payback in about 15.9 years.
2026 6kW Cost
$17,400
Monthly Savings
$91
Production / kW
1,343 kWh
Panel Count
~15
4.6
Peak Sun Hours/Day
13.6¢
Planning Rate (¢/kWh)
15.9 yr
Payback Period
$37k
25-Year Savings
Washington Solar Overview
Calculate Your Washington Solar Savings
Washington average: $129/mo
South-facing roofs produce the most energy
Add $8,000-$12,000 for whole-home battery backup
Annual Production
kWh/year
Annual Savings
per year
Net System Cost
no 2026 federal credit applied
Payback Period
break-even time
Bill Offset and Export Assumptions
Current Annual Bill
$1,548
Estimated Usage
11,408 kWh
Bill Offset
71%
Used On Site
100%
Exported production is discounted in this planning model instead of being treated as a guaranteed one-for-one bill credit. For Washington, verify the current Pepco (Potomac Electric) export-credit method and any fixed monthly charges before relying on the payback number.
25-Year Total Savings
$37,369
Monthly Savings
$91
2026 Federal Credit
$0
Cumulative Savings vs System Cost
Cost Breakdown
| Item | Washington | National Avg |
|---|---|---|
| Gross System Cost (6kW) | $17,400 | $17,100 |
| 2026 Federal Residential Credit | -$0 | $0 |
| Net System Cost | $17,400 | $17,100 |
| Cost Per Watt | $2.90/W | $2.85/W |
Solar Potential in Washington
Sun Hours vs National Average
Washington gets 2% more sun than the national average.
Climate Advantages
- About 199 sunny days per year (planning estimate)
- Estimated average temperature: 44.7°F, cooler temps actually improve panel efficiency
- Assumed roof size: 1,961 sq ft, enough for a 108-panel system
Washington Solar Incentives & Programs
Federal Residential Clean Energy Credit (Section 25D)
For 2026 planning, JouleIO does not subtract a federal residential clean energy credit. The IRS says the Residential Clean Energy Credit was 30% for eligible property installed from 2022 through December 31, 2025, and is not available for property placed in service after December 31, 2025.
Source: IRS Residential Clean Energy Credit and IRS One Big Beautiful Bill provisions.
District of Columbia State Incentives
DC SREC program at $350-$400/MWh; property tax exemption; 2026 federal residential credit eligibility must be verified
Net Metering: Pepco (Potomac Electric)
JouleIO's planning data marks net metering or a solar export credit as available for Pepco (Potomac Electric) customers in Washington. Export credits can be at retail or below-retail rates depending on the current tariff, so confirm terms with the utility that serves your address.
Environmental Impact in Washington
3.4
Tons CO2 Offset/Year
55
Equivalent Trees Planted
0.8
Homes Worth of Energy
Based on 8,059 kWh annual production with a 6kW system. EPA average: 0.417 metric tons CO2 per MWh, 10,632 kWh per US home.
Solar Energy in Washington, District of Columbia
Washington, District of Columbia receives an average of 4.6 peak sun hours per day, providing excellent conditions for residential solar installations. With a planning electricity rate of 13.6¢ per kWh (EIA District of Columbia residential average for 2026-06: 24.39¢; U.S. average 18.34¢), below the national average, so payback is slower even with this calculator's 2.5% annual rate-increase assumption.
A typical 6kW solar system in Washington produces approximately 8,059 kWh per year, saving homeowners an estimated $1,094 annually. The system pays for itself in about 15.9 years, after which you enjoy essentially free electricity for the remaining 9+ years of the system's warranty life.
JouleIO's dataset carries a modeled solar-adoption value of 7.2% for Washington. It is a rough planning placeholder, not a measured count of local installations, so use utility interconnection data or installer quotes if local adoption matters to your decision.
Methodology & Solar Data Sources for Washington
How we calculate Washington solar potential and savings: Annual production = system kW × estimated peak sun hours × 365 × 0.80 system derate × a roof-orientation factor. This is a simplified planning formula, not a PVWatts run for your address. Cost uses a planning price per watt for District of Columbia, and bill savings use a planning electricity rate of 13.6¢/kWh (the EIA District of Columbia residential average for 2026-06 is 24.39¢/kWh).
- Peak sun hours for Washington (4.6/day) are a planning estimate in the typical range for District of Columbia, not a site-specific NREL NSRDB value. Enter your address in NREL PVWatts for a location-specific production estimate.
- System sizing defaults to a 6kW residential rooftop system with roughly 400W panels; adjust the size and monthly bill to match your home.
- Federal tax credit: modeled as 0% for 2026 residential installations because IRS guidance says the Residential Clean Energy Credit is not available for property placed in service after December 31, 2025.
- Exports are discounted rather than credited 1:1 at retail, because many utilities have shifted to net billing or avoided-cost export rates. Verify your utility's current tariff.
- 25-year savings assume a 2.5% annual electricity-rate increase and do not subtract panel degradation, inverter replacement, or maintenance.
Authoritative US solar data sources:
- NREL PVWatts Calculator, official US solar production estimator
- NREL National Solar Radiation Database, site-level solar irradiance data for checking your address
- IRS Residential Clean Energy Credit, 2026 federal residential credit status
- IRS One Big Beautiful Bill provisions, clean energy credit expiration overview
- DSIRE, State Solar Incentives, searchable database for District of Columbia
- EIA Electric Power Monthly Table 5.6.A, District of Columbia residential average price
- ENERGY STAR Solar, efficient solar product database
Solar Disclaimer: Solar savings vary based on roof orientation, shading, system quality, installer markup, financing terms, utility rate plan, and policy changes. Always get 3+ quotes from NABCEP-certified installers and review contracts carefully. Tax credit eligibility depends on tax liability, consult a tax professional.
Reviewed by Marcus Delacroix · Last updated 2026 · Sun-hour and rate inputs are planning estimates; EIA state rate period 2026-06
Frequently Asked Questions
How much do solar panels cost in Washington, DC?
The average cost of a 6kW solar panel system in Washington is approximately $17,400 before local or state incentives ($2.90/watt). For 2026 planning, this calculator does not subtract a federal residential clean energy credit because IRS guidance says the credit is not available for property placed in service after December 31, 2025. DC SREC program at $350-$400/MWh; property tax exemption; 2026 federal residential credit eligibility must be verified
How many solar panels do I need in Washington, DC?
A typical 6kW residential solar system in Washington needs about 15 panels if each panel is rated near 400 watts. That system produces about 8,059 kWh per year in this estimate, or roughly 1,343 kWh per installed kW before shading, roof orientation, and inverter losses are customized.
How many peak sun hours does Washington get?
JouleIO models Washington, DC at about 4.6 peak sun hours per day and roughly 199 sunny days per year. These are planning estimates, not site measurements, so check your exact address in NREL PVWatts. This is near the national average, providing good conditions for residential solar panels.
What is the solar payback period in Washington?
The average solar payback period in Washington is approximately 15.9 years for a 6kW cash-price estimate before local or state incentives. After payback, your solar panels generate essentially free electricity for the remaining warranty life. Over 25 years, bill savings can reach about $37,369 before subtracting installation cost.
Does Washington have net metering?
JouleIO's planning data marks net metering or a solar export credit as available in Washington, where Pepco (Potomac Electric) is the likely utility (verify for your address). Export credits may be at retail or below-retail rates depending on the current tariff, and fixed monthly charges still apply.
Is solar worth it in Washington, DC in 2026?
Solar may still be worthwhile in Washington, especially for homeowners with high usage or strong local incentives, but the 15.9-year payback means quote comparison matters. For 2026 installs, JouleIO does not assume a federal residential credit; local incentives and net metering are the main financial drivers.