Remote Cabin in Northern Utah
Installer: Intermountain Wind and Solar
Project Overview
Set against the green farmland of Lancaster County, Springville Foods is now primarily powered by the sun and batteries. This image shows the store, PV array, and surrounding agricultural facilities that rely on resilient power.
Springville Foods is a full-service grocery store nestled in the heart of Pennsylvania Dutch country, serving a loyal base of Amish and rural customers since 2004. Like many businesses in remote or underserved areas, it historically depended on diesel generators to meet its energy needs, operating both a 100 kW primary and a 50 kW secondary generator. These units provided power to essential loads such as commercial coolers, freezers, HVAC, lighting, and point-of-sale systems. While reliable in principle, the diesel solution posed challenges: high fuel costs, regular maintenance requirements, and occasional load management limitations during peak usage.
In pursuit of sustainability, energy independence, and lower operating costs, the owners of Springville Foods partnered with CB Solar and Zonna Energy to transition to a modern hybrid power solution. The result is a clean, quiet, and efficient off-grid system powered primarily by solar and batteries, with diesel used only as a secondary backup.
Project Overview
CB Solar, Zonna, and Discover work on live commissioning of the AES 210HV cabinets and Sol-Ark 60K-3P inverters. Final performance checks on communication and closed-loop performance ensure a smooth transition to energy independence.
Discover’s AES 210HV high-voltage battery storage platform is the backbone of the new system. Two pre-assembled outdoor cabinets were installed, providing a total of 418 kWh of usable energy storage. These cabinets integrate seamlessly with two Sol-Ark 60K-3P commercial hybrid inverters, which deliver a combined 120 kW of continuous power output. A 75 kW photovoltaic array supplies renewable energy directly to the inverters and batteries.
The AES 210HV includes advanced thermal management via integrated liquid cooling and heating, built-in fire safety, thermal suppression (aerosol-based), and deflagration ventilation to meet UL9540 safety standards. Communication between the batteries and inverters is managed through the LYNK II Gateway, enabling real-time closed-loop control for optimized charging and discharging.
Key technical features of the system include:
- Storage Capacity: 418 kWh usable (two AES 210HV cabinets)
- Inverter Power: 120 kW continuous (two Sol-Ark 60K-3P inverters)
- Solar Capacity: 75 kW
- Grid Independence: Full off-grid operation with diesel generators now used only as backup
- Load Profile: Commercial refrigeration, HVAC, lighting, registers, and office equipment
Operational Benefits and Lessons for Off-Grid Designers
Two AES 210HV cabinets provide 418 kWh of high-voltage, liquid-cooled lithium storage. Prewired Sol-Ark inverters are wall-mounted next to the store's electrical room, allowing direct AC and DC integration.
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Today, Springville Foods operates primarily on solar energy and battery power, with diesel backup used sparingly during extended cloudy periods or high-load events. The transition has delivered immediate benefits:
- Fuel savings: Dramatic reduction in diesel consumption and generator runtime
- Maintenance reduction: Fewer mechanical hours and service events for generator upkeep
- Quiet operation: A quieter, cleaner environment for staff and customers
- Load flexibility: Smoother delivery of power to compressors and HVAC systems, especially during peak load transitions
- Future scalability: The system architecture leaves room for adding more PV and storage
This use case highlights how modern hybrid battery solutions can replace legacy diesel generators in rural commercial settings where grid access is undesired, limited, or unreliable. Grocery stores are among the most demanding off-grid applications due to their continuous refrigeration loads and sensitivity to power outages. The combination of Discover’s storage, commercial hybrid inverters, and intelligent communication enables businesses like Springville Foods to operate independently without sacrificing reliability or customer service.
Key Takeaways for Future Projects
- Utility-grade performance at commercial scale: This project showcases how Discover Energy Systems is bridging the gap between industrial BESS solutions and commercial installer needs. By delivering utility-grade reliability, safety, and performance in a cost-effective, scalable package, Discover empowers C&I projects that were previously out of reach due to complexity or cost.
- Simple integration with hybrid inverters: Discover’s AES 210HV platform is purpose-built for compatibility with commercial hybrid inverters like the Sol-Ark 60K. Its plug-and-play DC and communication interfaces significantly reduce installation time, eliminate guesswork, and lower the barrier to entry for commercial solar installers entering energy storage.
- Standards-driven safety and resilience: UL 9540 Listed & UL 9540A Large Scale Fire Tested architecture, integrated aerosol fire suppression, passive deflagration venting, and a liquid thermal management system ensure that even demanding off-grid loads can be handled safely and dependably.
- System design matters: Pairing 418 kWh of usable storage with 120 kW of inverter capacity provided ample headroom for cold storage, air conditioning, and peak-hour loads. The system design ensures reduced generator runtime and flexible growth paths for future loads or PV expansion.
- Collaboration is critical: The success of this deployment is a testament to the alignment between technology providers, local installers, and technical distributors. CB Solar’s field execution, Zonna Energy’s system design expertise, and Discover’s product integration support combined to deliver a solution that exceeded customer expectations.
Installer and Partner Contributions
CB Solar of Gordonville, PA, played a central role in the success of this installation. With deep experience serving agricultural and commercial clients in Pennsylvania, the CB Solar team delivered a turnkey off-grid system that was expertly installed and commissioned to meet the unique needs of Springville Foods. Their familiarity with both rural power infrastructure and high-voltage storage integration allowed them to anticipate and mitigate challenges related to refrigeration loads and seasonal solar variability.
Equally vital was the contribution of Zonna Energy. As a specialized off-grid distributor with a long history of supporting battery-based projects across North America, Zonna provided detailed system design guidance and technical support throughout the planning and commissioning process. Their recommendation of the Discover AES 210HV platform was based not only on cost and performance but also on safety features, inverter compatibility, and long-term serviceability. Zonna’s ability to provide both logistics and hands-on guidance proved instrumental in ensuring this project met its ambitious energy goals without compromising reliability.
Interested in a Similar Solution?
Discover Energy Systems, CB Solar, and Zonna Energy are available to support off-grid and grid-independent projects across North America. If you are a business, farm, or institution exploring energy storage to eliminate or reduce diesel reliance, this project is a strong reference point for what’s possible today. Get in touch with us.
Remote Cabin in Northern Utah
Installer: Intermountain Wind and Solar
Project Overview
Set against the green farmland of Lancaster County, Springville Foods is now primarily powered by the sun and batteries. This image shows the store, PV array, and surrounding agricultural facilities that rely on resilient power.
Springville Foods is a full-service grocery store nestled in the heart of Pennsylvania Dutch country, serving a loyal base of Amish and rural customers since 2004. Like many businesses in remote or underserved areas, it historically depended on diesel generators to meet its energy needs, operating both a 100 kW primary and a 50 kW secondary generator. These units provided power to essential loads such as commercial coolers, freezers, HVAC, lighting, and point-of-sale systems. While reliable in principle, the diesel solution posed challenges: high fuel costs, regular maintenance requirements, and occasional load management limitations during peak usage.
In pursuit of sustainability, energy independence, and lower operating costs, the owners of Springville Foods partnered with CB Solar and Zonna Energy to transition to a modern hybrid power solution. The result is a clean, quiet, and efficient off-grid system powered primarily by solar and batteries, with diesel used only as a secondary backup.
Project Overview
CB Solar, Zonna, and Discover work on live commissioning of the AES 210HV cabinets and Sol-Ark 60K-3P inverters. Final performance checks on communication and closed-loop performance ensure a smooth transition to energy independence.
Discover’s AES 210HV high-voltage battery storage platform is the backbone of the new system. Two pre-assembled outdoor cabinets were installed, providing a total of 418 kWh of usable energy storage. These cabinets integrate seamlessly with two Sol-Ark 60K-3P commercial hybrid inverters, which deliver a combined 120 kW of continuous power output. A 75 kW photovoltaic array supplies renewable energy directly to the inverters and batteries.
The AES 210HV includes advanced thermal management via integrated liquid cooling and heating, built-in fire safety, thermal suppression (aerosol-based), and deflagration ventilation to meet UL9540 safety standards. Communication between the batteries and inverters is managed through the LYNK II Gateway, enabling real-time closed-loop control for optimized charging and discharging.
Key technical features of the system include:
- Storage Capacity: 418 kWh usable (two AES 210HV cabinets)
- Inverter Power: 120 kW continuous (two Sol-Ark 60K-3P inverters)
- Solar Capacity: 75 kW
- Grid Independence: Full off-grid operation with diesel generators now used only as backup
- Load Profile: Commercial refrigeration, HVAC, lighting, registers, and office equipment
Operational Benefits and Lessons for Off-Grid Designers
Two AES 210HV cabinets provide 418 kWh of high-voltage, liquid-cooled lithium storage. Prewired Sol-Ark inverters are wall-mounted next to the store's electrical room, allowing direct AC and DC integration.
.
Today, Springville Foods operates primarily on solar energy and battery power, with diesel backup used sparingly during extended cloudy periods or high-load events. The transition has delivered immediate benefits:
- Fuel savings: Dramatic reduction in diesel consumption and generator runtime
- Maintenance reduction: Fewer mechanical hours and service events for generator upkeep
- Quiet operation: A quieter, cleaner environment for staff and customers
- Load flexibility: Smoother delivery of power to compressors and HVAC systems, especially during peak load transitions
- Future scalability: The system architecture leaves room for adding more PV and storage
This use case highlights how modern hybrid battery solutions can replace legacy diesel generators in rural commercial settings where grid access is undesired, limited, or unreliable. Grocery stores are among the most demanding off-grid applications due to their continuous refrigeration loads and sensitivity to power outages. The combination of Discover’s storage, commercial hybrid inverters, and intelligent communication enables businesses like Springville Foods to operate independently without sacrificing reliability or customer service.
Key Takeaways for Future Projects
- Utility-grade performance at commercial scale: This project showcases how Discover Energy Systems is bridging the gap between industrial BESS solutions and commercial installer needs. By delivering utility-grade reliability, safety, and performance in a cost-effective, scalable package, Discover empowers C&I projects that were previously out of reach due to complexity or cost.
- Simple integration with hybrid inverters: Discover’s AES 210HV platform is purpose-built for compatibility with commercial hybrid inverters like the Sol-Ark 60K. Its plug-and-play DC and communication interfaces significantly reduce installation time, eliminate guesswork, and lower the barrier to entry for commercial solar installers entering energy storage.
- Standards-driven safety and resilience: UL 9540 Listed & UL 9540A Large Scale Fire Tested architecture, integrated aerosol fire suppression, passive deflagration venting, and a liquid thermal management system ensure that even demanding off-grid loads can be handled safely and dependably.
- System design matters: Pairing 418 kWh of usable storage with 120 kW of inverter capacity provided ample headroom for cold storage, air conditioning, and peak-hour loads. The system design ensures reduced generator runtime and flexible growth paths for future loads or PV expansion.
- Collaboration is critical: The success of this deployment is a testament to the alignment between technology providers, local installers, and technical distributors. CB Solar’s field execution, Zonna Energy’s system design expertise, and Discover’s product integration support combined to deliver a solution that exceeded customer expectations.
Installer and Partner Contributions
CB Solar of Gordonville, PA, played a central role in the success of this installation. With deep experience serving agricultural and commercial clients in Pennsylvania, the CB Solar team delivered a turnkey off-grid system that was expertly installed and commissioned to meet the unique needs of Springville Foods. Their familiarity with both rural power infrastructure and high-voltage storage integration allowed them to anticipate and mitigate challenges related to refrigeration loads and seasonal solar variability.
Equally vital was the contribution of Zonna Energy. As a specialized off-grid distributor with a long history of supporting battery-based projects across North America, Zonna provided detailed system design guidance and technical support throughout the planning and commissioning process. Their recommendation of the Discover AES 210HV platform was based not only on cost and performance but also on safety features, inverter compatibility, and long-term serviceability. Zonna’s ability to provide both logistics and hands-on guidance proved instrumental in ensuring this project met its ambitious energy goals without compromising reliability.
Interested in a Similar Solution?
Discover Energy Systems, CB Solar, and Zonna Energy are available to support off-grid and grid-independent projects across North America. If you are a business, farm, or institution exploring energy storage to eliminate or reduce diesel reliance, this project is a strong reference point for what’s possible today. Get in touch with us.
The Third Edition of UL 9540, published in June 2023, introduced long-needed clarity for Battery Energy Storage Systems (BESS). Adoption across North America has progressed at varying speeds as Authorities Having Jurisdiction (AHJs) work through interpretation, alignment with existing enforcement practices, and integration into local approval processes. In Canada, the standard was incorporated into the 2024 Canadian Electrical Code (CEC, Part I), formally recognizing both AC- and DC-coupled ESS architectures. However, as with many newly adopted codes, consistent application at the local level has taken time, and differing interpretations among AHJs across America have contributed to extended review cycles and uncertainty for installers into 2025/26.
What Changed in UL9540 Third Edition?
The most important update was simple but impactful: UL9540 now distinguishes between AC ESS and DC ESS.
- AC ESS: A battery paired with an integrated inverter, certified as one unit.
- DC ESS: A standalone battery system certified to UL9540, designed to pair with a compatible, separately listed inverter.
Both system types are now evaluated to the same safety requirements, including UL9540A fire testing, system-level protections, and performance validation. The primary difference is how the Power Conversion Equipment (PCE) is documented: AC ESS includes the inverter within its certification, DC ESS verifies inverter/battery compatibility through manufacturer documentation. All the safety tests between AC ESS and DC ESS are identical.
This shift enables modern DC battery systems to be certified as UL9540 DC ESS, which offers flexibility in pairing with UL 1741 or CSA 107.1-listed inverters, rather than requiring fixed, pre-engineered packages.
The following table compares AC ESS with DC ESS.
| Item | AC ESS | DC ESS |
|---|---|---|
| PCE Integration | Included as part of the ESS certification and evaluated to UL 1741 or UL 62109-1 | Evaluated separately under UL 1741 or UL 62109-1 as standalone or multi-mode power conversion equipment |
| Certification Scope | ESS includes the inverter and battery as one integrated product | ESS functions as a standalone DC system compatible with multiple PCE |
| Compatibility Documentation | Fixed configuration, each pair included a specific inverter and battery | Managed by the manufacturer per UL 9540 Clause 46.14 |
| Safety Evaluation | UL 9540A fire testing and system-level protection | UL 9540A fire testing and system-level protection (identical evaluation as AC ESS) |
UL9540 in the Electrical Code
The UL9540 DC ESS fits into the National and Canadian Electrical Code (CEC) as published in the UL9540 Third Edition, as shown below.
| Component | Required Certification | Role |
|---|---|---|
| 1. Battery System | UL 9540 (Listed as “DC ESS”) | UL 9540 certifies the battery pack, BMS, and protection as a safe standalone system. |
| 2. Inverter | UL 1741 or CSA C22.2 No. 107.1 | The UL or CSA listing certifies the inverter’s safety and grid interaction capabilities. |
| 3. Interoperability | Manufacturer Manual / Closed-Loop Integration | The battery’s UL 9540 manual lists the specific inverter brand/model as compatible, or defines the integration settings. |
Why Many AHJs Aren’t Aligned
The challenge is largely interpretive, not technical. The disconnect between the national governing bodies and many parts of North America may be due to a misalignment in the mindset of both inspectors and system designers.
- First and Second Edition:
ESS = battery + inverter. Tested and certified as a single unit - Third Edition:
DC ESS = standalone battery system + separately certified inverter. Battery and inverter are tested and certified separately
Of all the components in a solar energy system, only the battery and inverter required being tested as a single unit. None of the other components was restricted in this way. Whether it be solar panels, junction boxes, DC disconnects, AC distribution panels, and so on, each component serves a particular purpose and is tested to ensure it operates as defined, in a safe and controlled manner. However, the UL listing for these components is not determined by their pairing with another component. That would be restrictive. Compliance is not, and should not, be contingent on connecting to a specific device, which was the case for batteries and inverters in the first and second editions of UL9540.
UL 9540 Third Edition addresses this issue by decoupling the inverter and battery. UL 9540 ensures safe operation by testing the safety and functional operation of the DC ESS components, including the BMS and control logic, thermal protection, electrical safety, and system integration. The boundaries of the DC ESS are firmly defined, allowing installers and AHJs to concentrate on other aspects of the installation, such as the installation environment, component spacing, and connection methods.
This shift in what to inspect in a UL 9540 Third Edition energy storage system requires training. The lack of understanding of the new regulations has resulted in varying timelines for adoption across North America, leading to inconsistent enforcement and frequent project delays. We look forward to everyone involved gaining a better understanding of the new regulations in 2026 and to increased adoption of best practices.
Verification Checklist for AHJs
To approve a DC ESS installation under UL9540 Third Edition, AHJs can follow a simple checklist:
- Verify UL9540 listing for the battery system.
- Review UL9540A test data for spacing and fire safety requirements.
- Confirm inverter certification (UL1741 or CSA 107.1).
- Check manufacturer compatibility documentation (per Clause 46.14 in the UL9540 standard).
- Ensure installation follows the battery manufacturer’s instructions.
This ensures that the battery and inverter are individually compliant and safe as a combined system.
Supporting Documentation from Discover Energy Systems
Discover Energy Systems provides integration guides and LYNK II Gateway documentation listing validated inverter models. The HELIOS ESS manual also lists inverter brands that are supported through its native communication protocol settings. These resources help AHJs verify compatibility and provide instructions that enable proper communication between the ESS and the inverter.
Conclusion
UL 9540 Third Edition represents a significant step forward in modernizing energy storage safety for both integrated AC systems and modular DC systems. The Third Edition offers increased safety and flexibility while maintaining protection requirements for all types of energy storage systems.
The full benefit of the new standard will be realized when AHJs fully understand and apply the new framework. As inspectors transition from fixed, pre-engineered systems to modular DC ESS paired with certified inverters, consistent training and documentation become essential. With guidance and manufacturer-supported compatibility tools, jurisdictions across North America can confidently approve safe, flexible, and future-ready energy storage installations, unlocking the full value of the UL9540 Third Edition.