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Solar panels in Kent, WA

Roofs in Kent get about 1,232 hours of usable sunlight a year — less than 83% of the cities we've measured. Here's what that means in cost, savings and payback, using real rooftop data rather than a national average.

1,232Sun hours / yr
26Panels typical
$20,748Cost after credit
17 yrPayback
Be careful in Kent. At a 17-year payback, solar here is a long-horizon decision, mostly because electricity is relatively cheap (11.3¢/kWh). It can still make sense if rates rise or you have local incentives — but check the numbers hard before signing.

Check your specific roof in Kent → City averages are a starting point; your own roof's size, pitch and shading change the answer a lot.

What a typical Kent solar system costs

A 26-panel system (10.4 kW) is about right for an average Kent home using 10,800 kWh a year. It would produce roughly 10,891 kWh annually and offset 100% of that usage.

Estimated economics by system size in Kent, at 11.3¢/kWh after the 30% federal tax credit
SystemSizekWh/yr Net costSaves/yrPayback
8 panels3.2 kW 3,351$6,384 $379 16.9 yrs
12 panels4.8 kW 5,027$9,576 $568 16.9 yrs
16 panels6.4 kW 6,702$12,768 $757 16.9 yrs
20 panels8 kW 8,378$15,960 $947 16.9 yrs
26 panels10.4 kW 10,891$20,748 $1,223 17 yrs

How we worked this out for Kent

Every number on this page comes from these seven steps. Nothing is a national average — the sunlight figure is measured from Kent rooftops.

#StepResult
1What one panel makes here
400W ÷ 1000 × 1,232 sun hrs × 0.85 system losses
419 kWh/yr
2Panels needed to cover typical usage
10,800 kWh ÷ 419 kWh per panel
26 panels
3System size
26 panels × 400W
10.40 kW
4Annual production
10.40 kW × 1,232 hrs × 0.85
10,891 kWh/yr
5Installed cost
10,400 W × $2.85 per watt, then −30% federal credit
$20,748
6Annual saving
3,780 kWh used as generated × 11.3¢  +  7,111 kWh exported × 11.3¢
$1,223/yr
7Payback
$20,748 ÷ $1,223 per year
17 years

Step 6 matters more than it looks. Only 35% of what a system this size produces in Kent is used the moment it is generated; the other 7,111 kWh is exported and credited one-for-one under net metering. Because exports here are credited at or near retail, that split changes the payback very little — 16.9 years against the 17 we show. In places where exports pay a fraction of retail the same split moves payback by years, which is why we model it explicitly rather than assuming.

Assumptions: 400W panels, 15% system losses (inverter, wiring, heat, soiling), $2.85/W installed, 10,800 kWh typical annual household use, 11.3¢/kWh electricity. Change any of those and every figure above moves — which is exactly why a single national "solar costs X" number is misleading.

Notice that payback barely improves as systems get bigger, and eventually gets worse. That's because you can only save money on electricity you were going to buy anyway. Once a system covers your usage, extra panels mostly generate exports at a much lower rate.

Why Kent gets 1,232 sun hours

That figure comes from Google's analysis of real rooftops across Kent — it already accounts for shading from trees, chimneys and neighbouring buildings, which is why it's lower than the raw "hours of daylight" figures you'll see elsewhere. An unusually open, unshaded roof in Kent reaches about 1,309 hours, roughly 6% better than typical.

The numbers behind this page

Typical usable sunlight1,232 hrs/yr
Unshaded roof1,309 hrs/yr
Electricity rate (Washington avg)11.3¢/kWh
Installed cost assumed$2.85/W
Panel size assumed400 W
Federal tax credit30%
Typical household usage10,800 kWh/yr
Power used as generated35%
Paid for exported powerfull retail (net metering)
Rooftops sampled here15
Google imagery from2024

When Kent actually produces

Annual totals hide the thing that catches people out: 40% of Kent's yearly sunlight arrives in May–July, and just 10% across November–January.

Estimated usable sun hours by month in Kent (latitude 47.4°)
MonthSun hrsShare of year
Jan 43
Feb 65
Mar 96
Apr 131
May 157
Jun 168
Jul 162
Aug 141
Sep 109
Oct 74
Nov 48
Dec 37

That is a severe seasonal swing — Kent produces roughly 4.5× as much in Jun as in Dec. A system sized to cover your annual usage will overproduce badly in summer and fall well short in winter, so how your utility credits exported power matters more here than in most places.

The annual total is measured from Google's rooftop imagery. Its split across months is calculated from solar geometry at Kent's latitude, not separately measured, so treat the monthly figures as the shape of a typical year rather than a forecast.

How Kent compares to the other 788 cities

MeasureKent Rank of 788
Usable sunlight1,232 hrs654th
Sunlight lost to shade6%315th most
Median roof size282 m²153rd largest
Electricity rate11.3¢732nd highest
Payback17 yrs755th fastest
Grid carbon696 kg/MWh250th dirtiest

What actually stands out about Kent:

  • Cheap electricity is the headwind. Washington power costs about 11.3¢/kWh. Low rates are good news generally, but they lengthen solar payback — there is simply less bill to displace.

Cities with almost the same sunlight

These are the closest matches to Kent's 1,232 usable sun hours from other states and provinces. Same sunlight, different electricity prices — which is usually what decides whether solar is worth it.

CitySun hrs RatePayback
Bradford, PA 1,22618.1¢ 10.6 yrs
Kailua-Kona, HI 1,25342.1¢ 4.5 yrs
Gresham, OR 1,25712.4¢ 15.4 yrs
Portland, OR 1,25812.4¢ 15.4 yrs

Nearby cities

See all of Washington → statewide sunlight, rates, incentives and every city we've measured.

Kent solar questions

How many solar panels do I need in Kent?

About 26 panels for an average home using 10,800 kWh a year. Kent roofs get 1,232 usable sun hours, so each 400W panel produces roughly 419 kWh annually. A typical Kent roof fits about 90 panels, so roof space is unlikely to be your limit.

Is solar worth it in Kent?

At 11.3¢/kWh and 1,232 sun hours, a typical system pays for itself in about 17 years and returns roughly $9,826 over a 25-year panel life. That is slower than average, so compare several quotes before committing. Exported power earns full retail credit here.

How much do solar panels cost in Kent?

A 10.4 kW system costs about $29,640 before incentives and $20,748 after the 30% federal tax credit. That works out near $2.85 per watt installed. Roof pitch, shading, electrical panel upgrades and equipment choice move the price most, which is why quotes for the same house can differ by thousands.

Worth reading before you buy

Estimates only, generated 2026-08-22 from Google Solar API rooftop samples and average Washington electricity rates. Not a quote and not financial advice. Your roof, usage, utility plan and local incentives will change these numbers — get real quotes before buying.