Level 3 EV charging infrastructure can place massive demand on the grid, especially at high-traffic charging depots where reliability is non-negotiable.
For this California-based bus charging depot, rising utility costs and grid instability were creating operational challenges that solar alone could not solve. The site needed a smarter energy strategy capable of supporting high-demand charging loads while improving resiliency and long-term project economics.
To meet those goals, the project deployed a Fortress Power eSpire commercial battery energy storage system paired with Keystone EMS.
Project Overview
Located in PG&E territory in California, the project combined battery energy storage, energy management software, solar PV, and EV charging infrastructure into a grid-tied resiliency solution designed to support a high-demand bus charging depot.
Project Details
- Location: California (PG&E territory)
- Solution: Fortress Power eSpire 125 kW / 233 kWh
- System Components: Battery Energy Storage System (BESS), Keystone EMS, Solar PV, EV Chargers
- Applications: Resiliency, demand mitigation, SGIP incentives, Virtual Power Plant (VPP) participation
The Challenge
The site experienced increasing energy demand due to Level 3 EV charging infrastructure, creating significant pressure on utility costs and overall site reliability. At the same time, rolling blackouts and grid instability in California created additional operational concerns. The customer needed a solution that could:
- Improve charging reliability
- Reduce expensive utility demand charges
- Support backup power capabilities
- Increase overall system resiliency
- Improve long-term project ROI
- Integrate with existing solar and EV charging infrastructure
As charging demand continued to increase, scalable energy management became essential.
The Solution: Fortress Power eSpire + Keystone EMS
To address these challenges, the site installed a Fortress Power all-in-one eSpire commercial battery energy storage system integrated with Keystone EMS.
The system was added after the original solar PV and Level 3 charging infrastructure had already been commissioned, allowing the customer to improve site performance without replacing existing infrastructure.
Why the eSpire System Was the Right Fit
The Fortress Power eSpire solution helped the customer:
- Improve site resiliency
- Reduce peak demand charges
- Optimize EV charging loads
- Unlock additional ROI through EMS-enabled grid services
- Support utility incentive programs
- Simplify system management through integrated controls
By combining battery storage with intelligent energy management, the system allows the charging hub to operate more efficiently during periods of high demand while improving overall reliability.
Smarter Energy Management for EV Charging Infrastructure
EV charging sites can create major spikes in electricity demand, especially when multiple Level 3 chargers operate simultaneously. Without battery storage, those spikes often result in expensive utility demand charges and added strain on the grid. Using Keystone EMS, the site can intelligently manage energy usage by:
- Reducing peak demand during charging periods
- Storing excess solar energy for later use
- Improving backup capabilities during outages
- Supporting grid-interactive energy programs
- Optimizing overall charging efficiency
This creates a more stable and predictable operating environment for both the customer and the charging infrastructure.
Results
The project delivered both operational and financial improvements for the customer.
Key Outcomes
- Improved reliability and resiliency for EV charging operations
- Reduced utility demand charges
- All-in-one hardware and software solution for simplified deployment
- Estimated payback period of less than six years
- Project delivery completed in under six months from purchase order
The installation demonstrates how commercial battery energy storage can help EV charging infrastructure operators manage growing power demand while improving long-term system performance.
