Case Studies

Castello Winery Commerical Microgrid

2 MIN READ

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.