Author Archive: Paul Fortunato
WCEC Newly Published Journal Article on Greenhouse Gas Emission Forecasts for Residential Heat Pumps
This study aims to inform policymakers about the greenhouse gas emission impacts of heat pump deployment in residential homes. Electric heat pumps eliminate direct burning of fossil fuels in homes but result in indirect emissions due to fossil fuels burned for electricity production. This paper presents the first detailed emission forecasts for operating either a heat pump or gas furnace for residential heating over a 15-year period, starting in year 2022 through 2036, in six regions across the US. The study accounted for long-run marginal emissions from electricity generation, emissions from natural gas combustion in homes, and fugitive methane and refrigerant emissions from leaks. The population weighted US average results show emission reductions for a heat pump over furnace to be 38–53% for carbon dioxide, 53–67% for 20-Year global warming potential (GWP), and 44–60% for 100-Year GWP, with reductions increasing over time. The impact of fugitive emissions from the furnace is significantly higher than that of the heat pump. While more energy efficient construction reduces overall emissions for both heating types, the forecasted percent emission reduction for replacement of a gas furnace with heat pump was not impacted by changes in home construction parameters.
R-466A Refrigerant Demonstration and Performance
Refrigerants used in vapor-compression air conditioners and heat pumps have been the subject of environmental regulations requiring the need to develop alternative solutions with lower global warming potential (GWP). In general, there is a trade-off when choosing alternative refrigerants between safety, performance, and GWP.
The California Air Resources Board (CARB) has approved a new regulation requiring refrigerants used in all new stationary residential air conditioning systems to have a 100-year GWP value of 750 or less. For reference, the most common refrigerant currently used in unitary air conditioning equipment is R-410A, which has a 100-year GWP of 2,088.
A number of refrigerant solutions have been developed to meet the CARB GWP requirement, but the majority of these refrigerants have a low level of flammability (A2L). While there are strategies for mitigating the risk of using flammable refrigerants, finding a non-flammable solution presents the easiest path to market and would not require additional safety controls and updates to codes and standards.
Energy Graduate Group Virtual Information Session
Thursday, December 16, 2021 | 2pm – 3:30pm PST
UC Davis’ Energy Graduate Group (EGG) is designed to meet the world’s growing need for highly qualified, thoughtful and dedicated leaders in sustainable energy systems. EGG offers MS and PhD degrees in Energy Systems in two tracks of study: Energy Science & Technology and Energy Policy & Management. Students take relevant coursework from across the UC Davis campus and conduct interdisciplinary research to address pressing environmental, economic, policy, and social challenges related to energy production and consumption facing California, the U.S., and the world.
In this Virtual Information Session you can:
- Learn more about the Energy Graduate Group
- Talk with students and faculty
- Discover what research faculty are conducting
- Find out about the application and admissions process