18 May 2017
Residential buildings consume significant amounts of energy for equipment, such as heating, ventilation, and air conditioning (HVAC), water heating, appliances, lighting, and general plug/outlet loads. In 2009, residential buildings accounted for 21 Quads of primary electrical energy consumption, which is 21% of the total primary energy consumption in the United States . Currently, this equipment is operated based on homeowner’s schedule with limited or no feedback on their impact to the state of the electric grid. However, in the future this equipment can be controlled to manage the electricity usage, which will mutually benefit the homeowner and the utility companies. As such, significant potential for savings and demand control exists through the deployment of a retrofit control system for monitoring and coordinating various residential energy loads. Appliance energy loads can be dispatchable, making them responsive to the electric grid’s needs, such as higher penetration of renewable energy. The key enabler to this strategy is a low-cost, retrofit home energy management system (HEMS) platform and standard communication methods for connecting the equipment to the HEMS. The HEMS must offer energy savings through enhanced control and must demonstrate load flexibility through intelligent dispatch. Once the control of residential loads for utility benefits is established, market-based financial incentives shall be developed for building-to-grid transactions . A HEMS for homes will enable: (1) improved energy efficiency and reduced peak demand, (2) connectivity across loads to make them responsive to grid needs at the distribution level, and (3) diagnosis of equipment inefficiencies. In this paper, we discuss an open-source HEMS platform for providing retrofit connectivity across multiple loads in residential buildings and supervisory control of these loads to improve energy efficiency, enable load flexibility, and reduce peak demand.