Electrifying Edifices

by Marcy Marro | July 1, 2022 12:00 am

Electrification is a vital trend in the move to reduce greenhouse gas (GHG) emissions from buildings, concurrent with the transportation electrification movement. Building electrification means using all-electric equipment for heating and cooling, domestic hot water, cooking, clothes drying, etc. While electricity grids are rapidly decarbonizing with the reduced costs and increased deployment of solar, wind and other green energy production, electrification is important because on-site use of natural gas and other fossil fuels remains a significant portion of building-related emissions. For example, in California, natural gas accounts for approximately 70% of all energy use in homes and 30% in commercial buildings. We cannot meet GHG reduction goals without addressing this area of energy use.

Along with efforts to decarbonize electricity grids, make buildings more efficient, and promote solar and storage, state and municipal governments from New York to California are implementing regulations to push electrification. These include banning natural gas hook-ups in new construction and requiring or incentivizing electric equipment conversions during renovation and replacement projects. For instance, last year, New York City launched the ElectrifyNYC[1] program to help residents install solar panels and heat pumps, and Washington State’s Building Code Council just voted to restrict the use of gas in new commercial offices, apartment towers and other large facilities, beginning in 2023.

Building electrification by itself is not a complete solution, as it is best combined with other building and grid scale initiatives to be successful. In new construction, prohibitions on natural gas are a complement to more stringent energy codes, demand response programs, and distributed generation (e.g., on-site solar) and storage initiatives. Some governments are incorporating electrification requirements within their building performance standards (BPS), making it part of a comprehensive existing building decarbonization effort, along with limits on energy usage, GHG emissions and peak demand, that phases in over time.

The least expensive time to electrify a building is at the time it is built, so electrification mandates for new construction make sense. But what about existing buildings? Since new regulations don’t mandate immediate conversions, electrification of existing buildings can be planned and phased to coincide with building life cycle events like renovations or end-of-service-life equipment replacement. When combined with other energy efficiency and peak load reduction strategies, like improved thermal envelopes and shading of west-facing windows, electrification can be cost-effective and reduce operational costs. In many locations, utility incentives can offset capital costs, and PACE programs can provide low-cost, long-term financing.

Skeptics have expressed concerns with electrification, suggesting that it is simply shifting emissions from buildings to power plants, and that it raises equity issues, and increases atmospheric refrigerant impacts. Let’s address these. It is reasonable to ask if there is a benefit to shifting GHG emissions from HVAC units, boilers and other building equipment to power plants, especially considering the varying grid emissions factors in different regions. For reference, the electricity grid CO2 emission rate for New York City is more than twice that of California or the Pacific Northwest. However, electric utilities in 39 states have renewable energy and carbon emission reduction mandates and others have set voluntary targets, so this disparity will diminish over time. For example, Consolidated Edison (ConEd), the utility serving New York City, is greening its power supply with an interim goal of 70% renewables by 2030, and a target of 100% clean electricity by 2040. Electrification will phase in over a similar timeframe, and the carbon emission benefit will be greater if these efforts are concurrent.

Further, buildings on average account for 60% of carbon emissions in cities. According to the Urban Green Council[2], furnaces, boilers and hot water heaters emit more CO2 in New York City than all uses of electricity combined. Additionally, methane has stronger heat trapping properties in the atmosphere than CO2, and fugitive methane emissions occur all along the natural gas delivery system. Concentrating natural gas usage at power plants will reduce opportunities for methane leaks in the system.

Some suggest that prohibitions on gas are inequitable, as natural gas has been seen as a low-cost fuel for heating and hot water, and all-electric buildings could increase utility costs for small businesses and low-income residents. However, natural gas is prone to greater price volatility than electricity and given that electrification is usually coupled with energy efficiency improvements, vulnerable customers should see lower, more predicable utility bills. There are other equity factors to consider as well.

A recent Harvard study found that pollution from fuel combustion in New York buildings resulted in an estimated 1,940 premature deaths and $21.7 billion in health impacts in 2017. Combustion appliances for cooking, and space and water heating emit dangerous pollutants, including fine particulate matter (PM2.5), nitrogen and sulfur oxides (NOx and SOx), volatile organic compounds, and ammonia.

A third concern is the global warming potential of refrigerants. The most efficient substitutes for natural gas equipment are electric heat pumps that use refrigerants, which, if released to the atmosphere, have powerful and persistent heat trapping properties. However, third-generation refrigerants, or Hydrofluorocarbons (HFC), used in new equipment have significantly lower global warming potential (GWP) than previous generations (CFCs and HCFCs). Additionally, new heat pumps are factory-sealed, plug-and-play systems that reduce leak potential, and the increased efficiency results in lower life-cycle emissions compared to natural gas equipment. New technologies using mid- and low-GWP refrigerants are advancing rapidly, which will further reduce this concern.

The latest Intergovernmental Panel on Climate Change[3] (IPCC) report emphasizes the need to act quickly on all fronts to address the climate crisis[4]. Implementation of renewable energy, energy efficiency, building electrification and other measures must advance concurrently, as we don’t have time for sequential development. Electrification can be cost-effectively integrated into new building designs and existing building capital improvement plans and provides operational cost savings and improved indoor air quality.

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Alan Scott, FAIA, LEED Fellow, LEED AP BD+C, O+M, WELL AP, CEM, is an architect with over 35 years of experience in sustainable building design. He is director of sustainability with Intertek Building Science Solutions in Portland, Ore. To learn more, follow Scott on LinkedIn at linkedin.com/in/alanscottfaia[5].

Source URL: https://www.metalarchitecture.com/articles/electrifying-edifices/

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