Written on: October 28, 2024
For several years now, there has been a vigorous debate about how we can shrink the carbon impact of our buildings. Today, U.S. Buildings are associated with roughly one-third of our country’s greenhouse gas emissions. So, what is the smartest, most effective and least disruptive way to make them greener?
Much has been made of the ways that these buildings are heated, with electrification advocates — plus quite a few government and agencies on the federal, state and local levels — pushing for the phasing out of traditional heating systems in favor of electric heat pumps. This one-size-fits-all strategy elides the fact the most impactful way to lower building-related emissions is to make electricity cleaner by decarbonizing our nation’s grids. Of course, that project is far from simple and raises a host of issues regarding grid reliability and costs to consumers.
Then again, addressing climate change is one of the most complex and consequential challenges of our lifetimes — and the way we heat our homes and businesses is a part of the challenge we can address. What sometimes seems to be missing from the conversation on building decarbonization are the people who live and work in these buildings.
With temperatures dipping and furnaces and boilers clicking on across the country, let’s talk about heat generation and energy content — and how we can protect people’s cold-weather comfort while shrinking their carbon footprints.
When considering the carbon impact of heating homes and businesses, we often focus on emissions and costs, which are important factors. However, we also need to look at the quality and reliability of the heat that different systems provide.
Propane is enduringly popular with homeowners because it generates a lot of heat. The U.S. Energy Information Administration states that one gallon of propane generates 91,452 Btu of heat energy. By contrast, a kilowatt-hour of electricity produces only 3,412 Btu. You need to consume a lot of electricity to achieve a comparable amount of heat.
As energy efficient as heat pumps have become, they still run up against performance limitations in freezing conditions. These systems depend on heat from outdoor air to keep buildings warm. That means that they often can’t deliver sufficient heat during periods of sustained frigid weather. Consumer Reports recommends that people in colder climates have a “backup system” powered by traditional heating sources. For many homeowners, this fallback option is the only way to ensure their families stay safe and warm in the coldest parts of the year.
Now, compare this to a modern propane furnace. Today’s high-efficiency gas-fired heating systems can have AFUE ratings of up to 98.5%. So, a building’s occupants feel virtually every one of the 91,452 Btu of heat energy per gallon of propane consumed. Propane furnaces can deliver air heated to 120°F in pretty much all weather conditions.
Renewable propane retains all the physical properties of conventional propane despite being produced using organic and recycled feedstocks. That means that a building heated with renewable propane would see immediate and substantial reductions in its carbon intensity without sacrificing heat energy in the process.
But what about the electrification alternative? We have already established that buildings in many parts of the country would see significant hits to their heating capacity in the winter with heat pumps. Widespread electrification of buildings would also increase the demand for U.S. grid electricity, which has a much higher carbon intensity score than either conventional or renewable propane:
| Carbon intensity (in grams CO2 equivalent per magajoule) | |
|---|---|
| Average U.S. Grid Electricity | 130 |
| Conventional Propane | 79 |
| Renewable Propane from domestic, non-rendered, used cooking oil | 20.5 |
We also need to consider the impact on homes in rural areas that lack the reliable grid power infrastructure of denser population centers. These are the buildings that rely on propane as an energy source that isn’t grid-reliant. Renewable propane — blended with conventional propane or other low-carbon liquid gases — can serve as a heating fuel and a source for off-grid or microgrid power generation. This would provide immediate carbon reduction without meaningfully sacrificing heating capacity or dependability.
Do you want to stay informed about how renewable propane and other renewable liquid gases can lower emissions in an affordable, non-disruptive way? Please consider joining the Renewable Propane Alliance.