The Maryland Department of the Environment has established ambitious decarbonization goals, and the electrification of residential and commercial heating is a promising pathway for decarbonizing a large portion of the economy. To explore one aspect of how ground source heat pumps (GSHP) – systems that provide both heating and cooling – may contribute to the solution, Brattle Principal Dean Murphy, Associate Kasparas Spokas, and Senior Research Analyst María Castañer have prepared a paper for the Maryland Geothermal Association, “Ground Source Heat Pumps: Peak Impacts in Maryland.”
Heating and cooling account for a substantial share of the state’s greenhouse gas emissions, since heating in particular traditionally involves burning fossil fuels. Electric heat pumps can enable total decarbonization of heating and cooling if they are driven by clean or renewable electricity. Besides their decarbonization benefits, the authors discuss how GSHPs can help to reduce the electricity system peak, as well as the peak-related costs associated with the generation, transmission, and distribution components of the system.
During the summer, Maryland’s electricity system demand peaks due to air conditioning’s high electricity consumption. Because they are more efficient, using GSHPs for cooling requires considerably less electricity to provide the same amount of cooling, compared with a conventional air conditioner. Their relative efficiency is further enhanced because they use water to transfer heat to the ground; this water absorbs heat more readily and provides a cooler heat sink than the ambient air. This can make a GSHP nearly 40% more efficient than a conventional air conditioner under peak conditions.