Ancillary service for the grid via control of commercial building HVAC systems

The thermal storage potential in buildings is an enormous untapped resource for providing various services to the power grid. The large thermal capacities of commercial buildings in particular make the power demands of their Heating, Ventilation, and Air Conditioning (HVAC) systems inherently flexible. In this paper, we show how fans in air handing units (AHUs) of commercial buildings alone can provide substantial regulation service, with little change in their indoor environments. A feedforward architecture is proposed to control the fan power consumption to track a regulation signal. The proposed control scheme is then tested through simulations based on a high fidelity commercial building model constructed based on Pugh Hall located on the University of Florida campus. For the HVAC system under consideration, numerical experiments demonstrate how up to 15% of fan power capacity can be deployed for regulation purposes while having little effect on the building inside temperature. The regulation signal can be successfully tracked in the frequency band [1/τ₀, 1/τ₁], where τ₀ ≈ 3 minutes and τ₁ ≈ 8 seconds. Our results indicate that fans in existing commercial buildings in the U.S. can provide about 70% of the current national regulation reserve in the aforementioned frequency band.