GFO-23-308 – DC HVAC Nanogrid Module Development and Demonstration

This solicitation aims to reduce building dependency on grid electricity, increase energy efficiency of HVAC equipment operating on DC power, decrease burdens – and enhance access – to solar and heat pump adoption, and create business and manufacturing opportunities for those who develop DC HVAC nanogrid modules. The potential technology solution could be a modular system that includes an appropriately-sized PV array and energy storage integrated with a DC HVAC system. Such systems could support cost-effective decarbonization, summer electric demand management, and increased market adoption of clean HVAC electrification while avoiding the complexities of interconnection and stand-alone PV and storage installation, particularly for those in under-resourced communities. These systems could provide the benefits of solar and storage to ratepayers who have limited roof space or cannot afford a larger building-level PV/storage system. The installation would ideally be similar to an HVAC replacement, in that it would not require an inverter, onsite electrician, interconnection agreement, conduits, wiring, electric panel upgrades, or other utility-side requirements. Power from the solar PV and energy storage would be used entirely onsite and would not be exported to the grid. Rather, these systems would gain efficiency benefits from direct DC connections among the solar PV, storage, and HVAC equipment. Projects under this initiative could also eliminate or reduce building HVAC load during peak hours in summer months, improving reliability on the grid. The unit would typically be powered by solar PV and energy storage, except when either solar or stored energy is unavailable; at those times, the HVAC would use an AC/DC converter to be powered by the grid. The HVAC could continue operation uninterrupted during a grid outage when there is adequate solar and storage power available to meet the HVAC system’s load. Funded projects must develop and demonstrate the following technologies in existing buildings: ·       DC-powered HVAC equipment that directly uses onsite solar generated electricity; ·       Energy and/or thermal storage integrated into the system to improve cost effectiveness; and ·                A transfer switch incorporated into the module to isolate generation equipment from the grid and simplify installation. Projects must fall within one of the following project groups: ·       Group 1: Residential DC HVAC Nanogrid; and ·       Group 2: Commercial DC HVAC Nanogrid.