Castello Winery

Backup Power in Wine Country

This resilient microgrid system provides clean backup power in California’s wine country.

Castello di Amorosa, an authentically styled Tuscan castle nestled among Napa Valley’s vineyards, is a one-of-a-kind destination offering winemaking, tastings, and tours. Connected to the PG&E grid, the winery has experienced the growing impacts of wildfires, Public Safety Power Shutoffs (PSPS), and California’s broader power distribution challenges. To combat these risks, the winery installed a commercial microgrid powered by 375 kW of solar, a 250 kW / 556 kWh battery energy storage system, and upgraded generator infrastructure for parallel operation.

When a utility outage occurs, Generac’s ARC microgrid control system automatically islands the site, turning it into a self-sustaining microgrid solution. The ARC controller seamlessly orchestrates the hybrid mix of solar, storage, and generator assets to keep the facility running—even through extended, multi-day outages. The result is reliable power for both guests and the winery’s precious harvest.

During standard grid-connected operation, the microgrid technology continues delivering value. The ARC controller optimizes energy flow to reduce peak demand charges and shift usage based on time-of-use utility rates. This ensures meaningful cost savings each month.

Because of utility transformer constraints, Castello faces a 25 kW solar export cap. When solar generation is high and batteries are fully charged, ARC uses its advanced microgrid software to issue real-time solar curtailment commands—matching generation to facility demand and staying within export limits.

As a conditionally approved Performance Data Provider (PDP), Generac also supports the winery’s qualification for the California Self-Generation Incentive Program (SGIP), unlocking rebates and long-term ROI for the site’s solar powered microgrid.