Budderfly’s approach keeps things simple for on-site teams. “The operational impact is minimal,” said Christian Edwards, vice president of business development and strategy at Budderfly. “The battery system is managed alongside HVAC, lighting, refrigeration, and other loads, but our energy-as-a-service model means customers aren’t responsible for managing it. We handle deployment, monitoring, and optimization.”

Integration and Interoperability: No Black Boxes

One concern for engineers: Will these batteries play nice with existing controls and legacy BMS? Viridi’s answer is yes. Their systems support open protocols like BACnet and Modbus, and installation of real-time metering brings new insight into load profiles, plant commissioning, and M&V. “The availability of real-time data can be transformative,” said Williams, “enabling targeted conservation measures and improved sustainability reporting.”

Budderfly echoes this, emphasizing that a BESS is more than just another box on the wall. “When connected to building controls, batteries can more precisely manage grid strain during peak demand, improve resiliency, and even generate revenue through demand response,” Subbloie said.

Sizing, Modeling, and the Realities of Demand

How are these batteries sized, especially for sites with wild HVAC swings? Budderfly starts with site-specific data: historical consumption, peak events, and actual operational characteristics. “Quick-service restaurants are a classic case,” Subbloie said. “On a hot summer day, the combination of HVAC, refrigeration, and kitchen loads leads to sharp demand spikes. A properly sized battery can smooth those peaks, reducing costs and improving energy performance.”

Viridi points out that the biggest challenge isn’t the load profile, but the local utility tariff. “Some tariffs don’t incentivize load shifting or peak shaving, which can limit the economic drivers for adoption,” Williams said.

Hands-Off Maintenance and Support

Facility teams can breathe easy: Budderfly handles all maintenance, monitoring, and technical support. “Proactive monitoring maintains uptime and resolves most issues remotely,” Subbloie explained. “If a technician visit is needed, it’s scheduled – without impacting daily operations, since the BESS serves as backup, not primary power.”

Commissioning: The Real Bottleneck

The toughest part of any BESS project? Utility interconnection and permission to operate (PTO). “That’s typically the longest and least controllable part of the process,” Edwards said. They stress the importance of post-survey validation, system testing, and especially ensuring accurate metering and comms before energization. “A short verification window, comparing actual dispatch with the modeled profile, ensures optimal system function.”

Technical Deep Dive: Space, Safety, and BAS Integration

Viridi’s RPS50 battery modules, each about the size of a large suitcase, can be wall-mounted or stacked – making them viable for tight mechanical rooms. They’ve been tested in extreme conditions and produce only minor heat loss. Integration with building automation systems is straightforward: “We support BACnet, Modbus, CANbus, DNP3, and Serial protocols,” Williams said. “Our cloud-enabled grid-edge gateway handles on-site intelligence and communications.”

Installations are fast: one recent project placed 75 battery packs (3.75 MWh) in 32 hours, with zero disruption to normal operations. Williams noted, “Connecting to main electrical gear may require a brief shutdown, but the installation itself is non-intrusive.”

Best Use Cases and ROI for HVAC Pros

Modern, high-SEER HVAC systems and new-generation heat pumps see the greatest benefit from BESS integration. Outdated, inefficient systems reduce the operational and financial impact. Budderfly’s preventative maintenance is key: “Continuous maintenance reduces downtime and extends equipment life.”

ROI is about more than energy savings – it’s about when energy is used. “Efficiency upgrades and controls cut total usage, but batteries optimize the timing,” Edwards explained. “Cost savings are clearest in before-and-after demand charges, demand response revenue, and avoided outage costs.”

Electrification and the Future: An Engineer’s Perspective

Electrification and grid-interactive buildings are changing the role of HVAC. Batteries aren’t just backup – they’re central to new energy strategies. Williams said, “HVAC systems are the largest load in the built environment. Battery storage helps offset HVAC peaks and supports the grid during extreme conditions.”

Budderfly’s strategy is all about interoperability and continuous management. “Highly controllable, real-time management of grid-responsive equipment is the key,” Edwards said. Their acquisition of Sunverge, a DERMS platform, has taken site-level demand response and predictive modeling to new heights.

What HVAC Engineers Need to Know Next

Both companies agree: HVAC engineers must understand the electrical context of their systems. “Knowing a chiller’s peak draw and sizing batteries accordingly is powerful,” Williams said. Cross-training in electrical concepts is a must, and engineers who can put system design in the context of regional and grid-level challenges will lead the next wave of energy-smart buildings.

“The modern HVAC engineer is no longer just managing performance inside the building,” Edwards concluded. “They’re transforming buildings into active participants in the energy ecosystem, shaping how our shared grid performs for everyone.”

As BESS technology goes mainstream, the takeaway is clear: success hinges not on the sophistication of any one component, but on the expertise and foresight of the engineers who make it all work together.