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State rules that apply
- What the rule says: “must credit the customer-generator for the excess kilowatt-hours generated during the billing period”[1]
What it means for sizing and batteries
When exports earn close to the retail price, sizing the system to cover your yearly use is usually the best value, and a battery is mainly for backup rather than savings.
The calculator uses the statewide rule until we add utility rates. See what solar costs in Oregon.
FAQ
Frequently asked questions
Does Oregon have net metering?
ORS 757.300 requires utilities to offer net metering and to credit customer-generators for excess kilowatt-hours generated in a billing period; the statutory size limit is 25 kW, though the PUC may set a higher limit for public utility customers.
sources
[ 1 ]Every number on this page links to one of these sources. Dates show when we last checked each one.
- ORS Chapter 757 (757.300 Net metering facilities) - Oregon Legislatureoregonlegislature.gov · checked Nov 5, 2026
Tariffs last re-checked November 5, 2026.
Change log
- Monthly output per kW in Portland updated to [36.7, 51.6, 88.4, 106.7, 133.2, 131.1, 160.3, 136.0, 118.1, 76.6, 45.8, 36.1] kWh/kW/month (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).
- Average solar radiation on the panels in Portland updated to 4.06 kWh/m2/day (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).
- Solar output per kW in Oregon (PVWatts, Portland) updated to 1120.7 kWh/kW/yr (NREL/NLR PVWatts v8 (1 kW-DC, fixed roof mount, 20° tilt, south-facing, 14% losses, TMY weather)).