Something odd is happening across Sonoma County this fall. The federal 30% credit that sold rooftop solar for more than a decade is gone, yet the calendar is putting more pressure on homeowners, not less. The reason is a quieter state rule that rarely appears in sales brochures, and it runs out on January 1, 2027.
Since the early 1980s, California has kept qualifying solar systems out of property tax reassessment. Add a pool or a garage and the assessor recalculates your home’s value. Add panels, and the assessed value stays where it was. That exclusion is set to stop applying to new systems at the start of 2027. A bill to push the date out to 2032 was parked in an Assembly committee this spring, and no extension has become law. In a county where home values already run high, the gap between an excluded system and a reassessed one can grow into real money over years of ownership.
What “done” means to the assessor
Signing a contract before December does not count. The system has to be active, which for a house means permitted, installed, inspected and interconnected with the grid. In PG&E territory, that final step is Permission to Operate, and it arrives on the utility’s schedule, not yours.
A typical residential job moves through these stages:
- Site visit, shade review and system design
- City or county permit application
- Installation, usually a few days on the roof
- Local inspection
- Utility interconnection review and Permission to Operate
Each handoff can add a week or more, and the holiday stretch slows everyone. Homeowners starting conversations now still have room. Those waiting until Thanksgiving are gambling.
| When | What shifts | Who notices |
|---|---|---|
| Already passed (end of 2025) | Federal Section 25D credit ended for owned residential systems | Cash and loan buyers |
| January 1, 2027 | Property tax exclusion stops covering newly qualifying systems | Anyone not interconnected in time |
| Every spring | Surplus exports paid out at the Net Surplus Compensation rate, capped at $5,000 | Households that export more than they use yearly |
| Every fire season | Public Safety Power Shutoffs become possible | Homes in High Fire Threat Districts |
Why a bigger array is no longer the smarter array
Under California’s net billing rules, power you send back to the grid earns far less than power you buy. Exports are credited somewhere around 5 to 8 cents per kWh, while PG&E’s retail price sits near 42 cents. A system sized to push lots of energy back mostly earns pennies.
Sonoma Clean Power, the default provider for most of the county, runs its own version called the Solar Billing Plan. Export credit values move with the hour, the day and the season, and they climb highest during summer evenings when demand peaks. That detail rewards a different design logic. Arrays should be sized closer to what the home actually uses, with west facing panels sometimes earning their keep by producing later in the afternoon. Southern parts of the county, where morning fog lingers around Petaluma and the lower valley, feel this even more.
One more quiet change: PG&E now applies a flat monthly connection charge that Sonoma Clean Power estimated would rise to about $24 this year. Panels cannot erase it, so a “zero bill” promise no longer holds up.
Batteries, fire maps and the rebate people overlook
Storage has moved from luxury to the piece that makes the numbers work. A battery soaks up cheap midday production and releases it in the evening, when grid power costs the most and export credits would otherwise be thin.
Large parts of Sonoma County fall inside PG&E’s Tier 2 and Tier 3 High Fire Threat Districts. Homes there may qualify for Self Generation Incentive Program rebates, and the equity resiliency tier has paid up to $1,000 per kWh for households meeting its eligibility rules. On a 13.5 kWh battery, that can cover most of the hardware cost. Funding and eligibility shift, so checking current availability before signing matters.
Batteries and generators also solve different outage problems. A battery handles a short shutoff silently and instantly. A multiday event, the kind Sonoma saw during past fire seasons, drains storage fast unless panels can recharge it, which is why some rural properties keep a standby generator as a second layer.
For homeowners trying to line all of this up before the deadline, having one crew handle the whole electrical picture saves weeks of back and forth. EFI Electric, a family owned, licensed contractor based in Santa Rosa, pairs Solar Installation in Sonoma with Tesla Powerwall battery setups, standby generator installs and the panel upgrades that often decide whether an interconnection goes smoothly. The team handles permits and utility paperwork, offers free no obligation estimates, and is known among local reviewers for flat, clear quotes without surprise add ons. If the January clock matters to your plans, a site visit this fall is the simplest way to see whether your timeline still works.
The electrical panel nobody photographs
Plenty of older homes in Santa Rosa, Sebastopol and the valley still run on 100 amp service. Electrical code limits how much solar can back feed into a panel’s busbar, and adding a battery, EV charger or heat pump tightens that math further. Sometimes the fix is a main breaker adjustment. Often it is a full 200 amp upgrade, which requires utility coordination of its own and can stretch a schedule. The federal credit that once helped pay for supporting panel work ended at the same time as the solar credit, so this cost now sits entirely with the homeowner.
A practical read for the rest of the year
Moving now makes the most sense for households planning to stay put, homes inside fire threat zones, and families with heavy evening use from cooking, EVs or air conditioning. Since the property tax exclusion lasts until the home changes hands, someone planning to sell within a year or two gains less from rushing.
Roof age deserves a hard look first. Removing and reinstalling panels later to replace shingles costs thousands, so a roof with less than a decade left should usually be replaced before anything goes on it. And for anyone who cannot use a tax benefit at all, leases and prepaid power purchase agreements still carry a federal credit on the provider’s side, which usually shows up as a lower price.
The incentive picture in Sonoma is thinner than it was two years ago, but it is far from empty. What changed most is timing and design. The homes that come out ahead are the ones sized for how the family actually lives, backed by storage, and switched on before the calendar turns.
