Solar System Sizing Tool — Spokane, WA

Use our interactive tool to determine the right solar system size for your home in Spokane. Adjust your monthly electricity bill and home size to see a personalized recommendation based on local solar conditions.

Size Your Solar System

$

Local rate: 11.5¢/kWh

ft

Peak sun hours: 3.8h/day

8.9

System Size (kW)

23

Panels Needed

414

Roof Space (sq ft)

$25,301

Est. Cost

12,313

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 Spokane, WA:

  • Electricity usage: Your monthly bill is converted to annual kWh consumption using the local rate of 11.5¢/kWh.
  • Solar irradiance: Spokane receives an average of 3.8 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 Spokane is 1,750 sq ft.

Solar at a Glance: Spokane, WA

11.5¢

Avg Rate / kWh

3.8h

Peak Sun Hours / Day

8.9 kW

Avg Recommended Size

23

Avg Panels Needed

$25,301

Est. Cost (before incentives)

Avista Utilities

Utility Provider

Other Cities in Washington

Related Resources

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