• Kyle J Wacyra, PE

Electrification vs. Fuel Switching for Reducing Carbon Emissions

Electrification is all the rage, not just with the inherent market push for Electric Vehicles (EV), but also with electrifying our buildings.

The major implication of electrification of buildings revolves around how we heat them.

Certain locations with milder climates, such as California, may have no problem transitioning to all-electric buildings, as heating with air-source or water-source heat pumps is relatively practical (note: Variable Refrigerant Flow (VRF) systems are a form of heat pump).

Other locations with extreme cold winters, such as North Dakota, may gawk at how expensive it would be to heat purely through electric resistance.

This article looks at an example and provides numbers behind the implications of electrification vs. fuel switching for the sake of reducing carbon emissions.

First, it's important to understand where emissions are generated (ie Scope 1 vs Scope 2).

For more info, read our article on the topic here: https://www.cap-eff.com/post/save-money-reduce-carbon-emissions

Let's look at a Variable Air Volume system with re-heat, either through heating hot water or electric resistance.

Heating hot water is ideally provided by a high-efficient condensing natural gas boiler. With the natural gas combustion occurring on-site at the building, this implies Scope 1 emissions.

Electric resistance for heating relies on electricity from the power plant, where the combustion occurs (today mostly from natural gas) to generate the electricity, which is then transported and delivered to the building. This implies Scope 2 emissions which account for losses along the transmission lines.

So comparing BTU to BTU, which has more Source Carbon Dioxide equivalent (CO2e) emissions associated with heating?

Understand that 1 therm of natural gas is equal to 100,000 BTUs, which is equal to 29.30 kWh.

1 therm of natural gas is equal to 0.0053 metric tonnes CO2e*.

29.30 kWh is equal to 0.0096 metric tonnes CO2e**.

So as you can see, BTU for BTU, it's actually better to utilize fuel switching to natural gas for heating if the end-goal is reducing Source CO2e emissions.

Source* https://www.epa.gov/sites/production/files/2016-03/documents/stationaryemissions_3_2016.pdf

Source** https://www.epa.gov/sites/default/files/2020-01/documents/egrid2018_summary_tables.pdf

THAT BEING SAID - that's only if the status quo of how we produce our electricity remains the same as today.

It is apparent that regulations are coming (or are already happening) to encourage utilities to cleanly produce electricity from renewable energy (wind/solar/hydro/geothermal, and we'll throw in nuclear for being 'clean' although technically not renewable) versus from fossil fuels (coal, diesel, natural gas).