90.6

Risk Grade

Fail

Wine country county with Williamson Act agricultural preserve covering approximately 90% of county land; county supervisors have adopted explicit policy opposing utility-scale solar on Agricultural Preserve land; Williamson Act cancellations effectively blocked; wine industry (~$2B+ annual economic impact) and tourism sector strongly oppose industrial solar on vineyard land; near-prohibition posture earns D-grade; rooftop and winery-integrated solar permitted but no utility-scale pathway on ag land

Assessment Snapshot

Population

136484

State Rank

#43

Compliance

78%

Trajectory

Moratorium Status

✓ No Active Moratorium

No specific moratorium information available.

Ordinance & Regulations

Setback Requirements

500 ft from occupied residences; 200 ft from property lines; additional buffers from established vineyards and winery operations

Zoning Mechanism

Conditional Use Permit (CUP) required; full CEQA EIR required for utility-scale; Williamson Act contract cancellation effectively blocked by county policy; Agricultural Preserve zoning prohibits non-agricultural land uses including solar farms

Acreage Caps

Solar farms effectively prohibited on Agricultural Preserve land (~90% of county); rooftop and building-integrated solar encouraged

Spacing Rules

None specified

Size Restrictions

Utility-scale ground-mount effectively prohibited on Agricultural Preserve; small building-integrated and winery rooftop solar permitted by right

Board Sentiment & Political Risk

Sentiment Analysis

Strongly opposed — wine industry, agricultural preservationists, and tourism interests united against utility-scale solar on vineyard land; BOS has voted unanimously to protect Ag Preserve character; 2022 policy statement explicitly opposed

Basis for Assessment

BOS unanimous votes against Ag Preserve conversion; county policy statement 2022; winery association statements; Napa County Farm Bureau positions; public hearing records

Political Risk Factors

Worsening

Board Members

Brad Wagenknecht | D | 2026; Ryan Gregory | D | 2028; Anne Cottrell | D | 2026; Alfredo Pedroza | D | 2028; Joelle Gallagher | D | 2026

Grid, Utilities & State Context

Grid Operator

CAISO — PG&E Balancing Authority

Utilities

Pacific Gas & Electric (PG&E)

State Permitting Process

County zoning + CEQA review required; CEC siting jurisdiction for projects >50 MW on state/federal land; Coastal Commission review for coastal zone; DRECP DFAs streamline desert county permitting

State Incentives

Federal ITC eligible; California Self-Generation Incentive Program (SGIP) for storage; CA Renewables Portfolio Standard procurement; CPUC approved procurement programs

Development Activity

Active/Completed Projects

Winery rooftop solar (multiple, aggregate ~5 MW); small distributed solar on non-preserve parcels; no utility-scale ground-mount approved

Denied/Withdrawn Projects

Multiple applications for solar on Agricultural Preserve land rejected or withdrawn (2018–2024); Robert Mondavi Winery area solar denied (2019); American Canyon area utility-scale rejected (2022)

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Napa County, CA — Solar Development Risk Assessment