The balancing act between energy supply and demand is becoming more delicate as renewable energy sources proliferate, creating both opportunity and complexity for utilities and building operators. A recent study led by Akihiro Imaizumi from the Graduate School of Environmental Studies at Nagoya University offers a practical solution by demonstrating how multiple buildings can coordinate their centralized air-conditioning heat source systems to participate in demand response (DR) programs—effectively turning buildings into flexible grid assets.
The research, published in the *E3S Web of Conferences* (translated from *E3S Web des Conférences*), focuses on a challenge familiar to energy managers: how to reliably deliver “negawatts”—the reduction in power consumption from baseline levels—during periods of grid stress. Traditionally, large centralized heat source systems, despite their significant energy footprint, have been underutilized in DR due to operational complexity. Imaizumi and the team set out to change that by designing a cooperative control method that synchronizes three buildings with different energy systems: two using combined gas-electric heat sources (Buildings A and C) and one equipped with a water thermal energy storage system (Building B).
The innovation lies in the timing and adaptability of the control strategy. By simulating expected heat loads and outdoor conditions 30 minutes before DR activation, the system can dynamically adjust target power consumption and the number of operating heat sources to meet negawatt targets every 30 minutes. This real-time recalibration proved critical. During initial tests, the researchers found that without adjustments, the buildings sometimes missed their DR targets at the start of the control period. But by resetting power consumption targets based on short-term forecasts, they were able to stabilize performance and consistently deliver the required negawatt capacity across the building group.
“This cooperative approach allows buildings to act not as isolated consumers, but as coordinated participants in the broader energy ecosystem,” Imaizumi explains. The implications are significant: large commercial and institutional buildings, which often house centralized HVAC systems, could become reliable sources of grid flexibility—supporting renewable integration, reducing peak demand, and potentially generating revenue through DR programs.
For energy utilities and facility managers, the findings suggest a scalable pathway to unlock latent demand-side resources. Instead of retrofitting buildings with new equipment, operators may only need to upgrade control systems and coordination protocols. The study also highlights the growing role of thermal energy storage, as seen in Building B, which acts as a buffer to smooth out power fluctuations.
As climate goals tighten and grid decarbonization accelerates, the ability to harness existing infrastructure for demand response will be invaluable. Imaizumi’s work points toward a future where buildings don’t just consume energy—they help manage it.