17125 NW St Helens Rd, Portland · 3 bd / 3 ba · 2,657 sq ft · built 1980 · ~2/3 acre · sized for up to 10 people · estimates, not a quote
House and assumptions
Moves usage below. 4 now, planning for 10
All-electric, heat pump, well pump, 1 EV. Oregon avg home ≈ 950
Check "per kWh" on a recent bill
Over 100% just donates credits each March
85% assumes some tree clearing or a ground mount in the sunny part of the lot
10 people: fridges, freezer, well pump, lights, Wi-Fi, some heat
Winter storm outage planning
What this house needs
How the power flows
A year of solar vs usage
Solar producedHouse usage
The money
PGE's ~$18–20/mo base charge stays no matter what, so it's left out of savings.
Can it earn money?
Exporting power: no cash. PGE credits exports 1:1, but unused credits are donated to low-income customers every March. Size to your usage, not bigger.
Battery: yes, as bill credits. PGE's Smart Battery program has paid $1.70 per kWh your battery discharges during grid events (about 10–15 a year). It may not stack with an upfront battery rebate, so confirm with PGE.
Federal tax credit: gone. The 30% residential credit ended Dec 31, 2025.
Energy Trust of Oregon: battery incentive of $400/kWh, up to $5,000, plus a solar incentive that steps down each quarter.
Assumptions. Portland solar yield ~1,100 kWh per kW of panels per year before shading; summer-heavy production with a winter-heavy usage profile. Battery = 13.5 kWh usable (Powerwall-class). 25-year value assumes 3% yearly rate increases and 0.5% panel degradation. Usage model: ~1,150 kWh/mo fixed (heat pump heating and cooling for 2,657 sq ft, well pump, fridges and freezer, one EV) plus ~120 kWh/mo per person (hot water, laundry, cooking, devices). Water, heat fuel and roof direction aren't in the listing, so this assumes all-electric as the worst case. If the house has gas heat or a gas water heater, usage drops a lot. The site is wooded hillside along Hwy 30, so the house roof alone likely won't fit or see enough sun for a system this size. A ground mount in the sunniest part of the property, plus some tree clearing, is the realistic play. Get a site survey before trusting the sun number.