Can heat‐pumps provide routes to decarbonization of building thermal control in the US Midwest?

• Published in: Energy science & engineering 2022-08, Vol.10 (8), p.2612-2621
• Main Authors: Doak, Austin, Stanier, Charles, Anthony, Jerry, Udaykumar, H. S.
• Format: Article
• Language: English
• Subjects: Carbon; Case studies; Climate change; Climate change mitigation; Cold regions; Cost control; economics; Efficiency; electric power systems; Electricity; Electricity generation; Electricity pricing; Electrification; Emissions; Energy; energy systems; environmental impact; Fluctuations; Fossil fuels; Gas heating; Greenhouse gases; Heat; Heat exchangers; Heat pumps; Heating; Life cycles; Natural gas; Natural gas prices; Operating costs; Renewable energy
• ISSN: 2050-0505; 2050-0505
• DOI: 10.1002/ese3.1159

Climate change mitigation demands rapid decarbonization; in cold regions such as the US Midwest, building thermal control (BTC) presents a potential for significant cuts in emissions by combining renewable energy with heat pumps. Trends in natural gas and electricity pricing over the period 2007–2020 have significantly upended economic feasibility of this decarbonization approach. Heat pump‐based BTC has moved from being cost advantageous in operations but higher GHG emitting (in 2007), to the exact opposite—higher cost but lower emitting (in 2020). Due to energy price fluctuations, the coefficient of performance required of a heat pump to breakeven on operational cost with high efficiency natural gas heating has doubled, changing from 2.25 to 4.5 over the period 2007–2019. The value of 4.5 is infeasible for all available cold‐climate heat pump systems. Thus, while electrification via both air‐source and ground‐source heat pumps is a commonly identified component of decarbonization plans in the region, actual implementation has declined. Improvements in heat pump performance, overcoming adoption barriers, and adopting policies that buffer long‐term climate solutions against short‐term price fluctuations are all needed. In part due to continuing decreases in carbon intensity of electricity, heat pump climate benefits can be substantial over project life cycles; however, there is no current policy mechanism to enable this benefit to be considered relative to short‐run economic considerations. Feasibility of decarbonization of building thermal control, a critical piece of climate change mitigation, is highly sensitive to the relative pricing of electricity and natural gas, which increased by 10% and decreased by 42%, respectively, in the past 12 years.