Scenario: a $250/month electric bill. Assumes 3%/yr rate increases, 0.5%/yr panel degradation and no federal tax credit (the 30% §25D credit ended for systems installed after Dec 31, 2025). How we calculate
Data approachEIA rates · NREL sun hours · 2026 federal policy · methodology
A $250/month electricity bill in Washington represents roughly 1,736 kWh per month at the state average rate of 14.40¢/kWh (EIA, Jan–Jul 2026 year-to-date). With 4.0 peak sun hours per day, offsetting that usage takes about a 17.4 kW solar system — roughly 44 panels at 400W — costing about $52,200 installed. Because the 30% federal tax credit ended for systems installed after 2025 and Washington has full retail net metering, simple payback is about 20.0 years, with an estimated $36,800 net over 25 years.
How Many Solar Panels for a $250 Electric Bill in Washington?
Washington electricity rates and sun hours change the math versus the US average. The sizing formula:
System size (kW) = Annual kWh ÷ (Peak sun hours × 365 × 0.82)
For a $250/month bill in Washington:
Annual usage: ~20,833 kWh/year
Peak sun hours: 4.0 h/day (Washington)
System size:17.4 kW DC (~44 × 400W panels)
Metric
Washington
US average
Rate
14.40¢/kWh
18.19¢/kWh
Sun hours
4.0 h/day
4.5 h/day
System size
17.4 kW
12.2 kW
Panels (400W)
44
31
Washington requires a larger system than the national average for the same dollar bill because higher consumption at lower rates. Use our solar system size calculator with your ZIP code for a roof-specific result.
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💰 System Cost
What Does Solar Cost for a $250/Month Bill in Washington in 2026?
At about $3.00/W installed (a blended 2026 US price; marketplace quotes often run lower), a 17.4 kW system in Washington costs about $52,200.
The 30% federal Residential Clean Energy Credit (IRC §25D) ended for systems installed after December 31, 2025, so a solar system you buy and install in 2026 gets no federal tax credit. Leases and PPAs are different: the installer that owns the system can still claim the commercial §48E credit for systems placed in service by the end of 2027 and may pass part of that value on through a lower monthly price.
Cost line
Amount
Installed cost (17.4 kW)
$52,200
Federal credit (25D) for 2026 installs
$0
Your cost before state/local incentives
$52,200
Getting three or more quotes matters more than ever without the federal credit: installed prices for the same system often differ by 20–30%.
📈 Payback Period
How Long Is Solar Payback on a $250 Bill in Washington?
Simple payback divides installed cost by first-year bill savings. Washington requires retail-rate net metering until utility caps are reached. We therefore assume solar offsets about 87% of a $250/month bill in Washington — roughly $2,610/year — for a simple payback of about 20.0 years.
Over 25 years, with 3% annual rate increases and 0.5%/year panel degradation, cumulative bill savings minus the installed cost come to about $36,800. Full retail net metering means each kWh you produce is worth close to your retail rate. Model your own numbers in our solar payback calculator.
Solar vs utility company · 25-year comparison
25-year totals for a $250/month electric bill: 3%/yr rate increases, 0.5%/yr degradation, no federal credit. Methodology
Washington Solar Incentives for a $250/Month Electric Bill
State and local incentives: Washington has no state income tax or solar tax credit; its sales-tax exemption for residential solar expired, so check current rules with your installer.
Net metering: Washington requires retail-rate net metering until utility caps are reached.
Check DSIRE and our Washington solar page for current rebates, net metering rules, and utility-specific programs before signing an install contract.
⚡ System Size
Washington vs US Average: $250/Month Bill Comparison
Washington
US average
Monthly bill
$250
$250
System size
17.4 kW
12.2 kW
Installed cost
$52,200
$36,700
Bill offset assumed
87%
75% (blended)
Simple payback
20.0 yrs
16.3 yrs
25-year net savings
$36,800
$40,000
Bottom line: A $250/month bill in Washington is a weak solar candidate with about 20.0-year payback in 2026. Calculate your Washington savings or compare all states on the $250 bill hub.
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At Washington's average rate of 14.40¢/kWh and 4.0 peak sun hours, a $250/month bill (~20,833 kWh/year) typically requires a 17.4 kW system — about 44 panels at 400W each. Use our solar system size calculator with your ZIP for a roof-specific estimate.
A 17.4 kW system in Washington costs roughly $52,200 installed at about $3.00 per watt. The 30% federal tax credit (25D) ended for systems installed after December 31, 2025, so there is no federal credit for a system you buy in 2026. Washington has no state income tax or solar tax credit; its sales-tax exemption for residential solar expired, so check current rules with your installer.
At $52,200 installed and ~$2,610/year in bill savings, simple payback in Washington is about 20.0 years. Washington requires retail-rate net metering until utility caps are reached.
With about 20.0-year payback and roughly $36,800 in estimated 25-year net savings, a $250/month bill in Washington is a weak case for buying solar in 2026. Consider a smaller system, a battery, or a lease/PPA quote, and compare against efficiency upgrades first. See the [Washington solar page](/states/wa/) for net metering and incentive details.
The US average needs a 12.2 kW system at 16.3-year payback. Washington needs 17.4 kW with 20.0-year payback — driven by Washington's 14.40¢/kWh rate and 4.0 daily sun hours.
14.4¢/kWh — Washington average residential price. Source: EIA Electric Power Monthly, Table 5.6.B (year-to-date through July 2026), residential average retail price (July 2026) (EIA)
Solar production
4 peak sun hours/day × 0.82 system derate. Approximate state-average daily solar resource (peak sun hours) based on NREL solar resource data (NSRDB); not location-specific — use NREL PVWatts for an address-level estimate. (NREL PVWatts)
Installed price
$3.00 per watt before incentives. Blended 2026 US residential installed price used by this site; EnergySage marketplace reported about $2.60/W (mid-2026); full-market medians are higher.
Federal tax credit
$0 for homeowner-owned systems installed in 2026 — the 30% §25D credit ended Dec 31, 2025 (IRS)
Net metering
Full retail net metering — solar assumed to offset 87% of the bill. Washington requires retail-rate net metering until utility caps are reached.
Estimates only — not tax, legal or financial advice. Get at least three installer quotes and confirm incentives with your utility and a tax professional.