Comparison of Short and Long-Term Energy Performance and Decarbonization Potentials between Cogeneration and GSHP Systems under MARKAL Scenarios

In response to the call for global carbon peaking and neutrality, this study mainly focuses on the comparison of energy-related carbon emissions and the performance of two promising heating, ventilation, and air-conditioning technologies (a ground source heat pump (GSHP) and cogeneration systems) over both short (2021–2030) and long (2031–2050) periods, considering the UK decarbonization plans. The simulation model of the building with the GSHP system is validated by the actual building heating energy data in 2020 and 2021, with yearly deviations of only 0.4–0.5%. The results show that the cogeneration system performed better than the GSHP system in a scenario when there was no electricity decarbonization plan in the future. However, under all of the MARKet ALlocation (MARKAL) scenarios, the GSHP system performed much better than the cogeneration system in terms of carbon reduction in both periods, which can achieve 47.8–84.4% and maximum 97.5% carbon emission savings in short and long-term periods, respectively, compared with the cogeneration system. Due to the truth that electricity decarbonization plans will be optimized and executed in the future, the GSHP system is more promising and recommended compared with cogeneration system in both short- and long-term periods in terms of only decarbonization potentials (e.g., reducing carbon emission and achieving carbon-related environmental protection).