Solar System Sizing Tool — Seattle, WA
Use our interactive tool to determine the right solar system size for your home in Seattle. Adjust your monthly electricity bill and home size to see a personalized recommendation based on local solar conditions.
Size Your Solar System
$
Local rate: 12.8¢/kWh
ft
Peak sun hours: 3.3h/day
10
System Size (kW)
25
Panels Needed
450
Roof Space (sq ft)
$28,394
Est. Cost
12,000
Annual kWh
100%
Energy Offset
Energy Offset100% of your usage covered by solar
0%50%100%
How We Calculate Your System Size
Your recommended solar system size is based on several factors specific to Seattle, WA:
- Electricity usage: Your monthly bill is converted to annual kWh consumption using the local rate of 12.8¢/kWh.
- Solar irradiance: Seattle receives an average of 3.3 peak sun hours per day, which determines how much energy each panel produces.
- Panel specifications: We use 400W panels, each requiring approximately 18 sq ft of roof space, which is standard for modern residential installations.
- Roof space: The total roof area needed depends on the number of panels. The average home in Seattle is 1,800 sq ft.
Solar at a Glance: Seattle, WA
12.8¢
Avg Rate / kWh
3.3h
Peak Sun Hours / Day
10 kW
Avg Recommended Size
25
Avg Panels Needed
$28,394
Est. Cost (before incentives)
Seattle City Light
Utility Provider
Other Cities in Washington
Related Resources
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