Cheap electricity is why the estimate matters
The EIA put the Oregon residential average at about 12.2 cents per kWh in April 2026, roughly half what a New England household pays. Every kilowatt hour your system produces is therefore worth about half as much as the same kilowatt hour on the east coast.
That is why the record here shows a payback measured in low double digits rather than in six or seven years. It is not a defect of the market, it is what happens when hydro keeps power cheap.
The consequence is that Oregon solar is more sensitive to error than solar in an expensive state. A production estimate overstated by fifteen percent does proportionally the same damage anywhere, but here there is less headroom absorbing it.
So spend your diligence on the production number rather than on the incentive lines. The incentives are largely fixed and checkable. The production estimate is a modelled projection with assumptions inside it.
How to interrogate a production estimate
Ask for the annual figure in kilowatt hours rather than only as a dollar saving. A dollar figure hides both the production assumption and the rate assumption inside one number, and you want to check each separately.
Ask what data source produced it and whether it uses location-specific irradiance for your address rather than a regional average. The Willamette Valley is cloudier than most of the state and a statewide figure will flatter it.
Ask what the model assumed about shading, and specifically what it assumed about tree growth over the system life. A model built on today canopy will overstate production in ten years, and the valley has mature trees.
Ask what escalation rate the projection applied to electricity prices. PGE raised residential rates about 5 percent effective April 1, 2026, so escalation is real, but a compounding assumption over twenty-five years can carry most of the headline savings on its own and should be stated rather than buried.
Sizing against the March rule
Oregon credits exports at the full retail rate and carries kilowatt hour credits forward, but at the end of the March billing cycle any unused credit is granted to the utility for distribution to its low-income assistance customers.
March is a difficult month to end on. You build credit through summer, spend it through a dark valley winter, and the line is drawn before spring production has recovered. A system that looked balanced on annual totals can still leave credit stranded.
So ask to see the monthly profile rather than the annual total: expected production and expected consumption month by month, with the credit balance tracked through to March.
That view is what shows whether a design is genuinely matched to your household or merely balanced on paper. It is also the view that makes the case for or against a battery honestly, since storage shifts generation into your own evening use rather than into credit that may be donated.
What is left, and when it is funded
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025, so a cash or loan purchase in Beaverton receives no federal tax credit. Section 48E survives at 30 percent for third-party owners under leases and power purchase agreements.
Treat the state ODOE Solar + Storage rebate as unavailable unless confirmed with ODOE, since its June 15, 2026 reopening was fully reserved.
Rebuild from the Energy Trust incentive of $3,500 for PGE customers through an approved trade ally, Solar Within Reach if your household qualifies under the Washington County income limit, and $400 per kWh up to $5,000 for a battery of at least 3 kWh connected to qualifying solar.
Then add retail-rate net metering with the March reconciliation, and the electricity you stop buying at a stated rate with a stated escalation assumption. Ask for the version with no escalation as well, because a case that survives it is a case you can rely on.