To combat climate change, many industries are weening themselves off fossil fuels and leaning more on electricity. It makes sense on paper. After all, we know that the combustion of fossil fuels contributes carbon dioxide, which accumulates in the atmosphere. That means any appliance that operates on fuel could be considered a culprit – your facility’s space heating system, for example.

That’s why many leaders in architecture and the building industry are leading the charge for decarbonization, with guidance from certification programs such as LEED and EnergyStar. In recent years these efforts have taken greater urgency as the frequency of extreme weather events intensifies. Multiple organizations are pushing for net-zero emissions in the building sector in the coming decades.

While these efforts are admirable, they tend to overlook propane as a clean burning, renewable energy source. Here’s how commercial appliances powered by propane compare to their electric and oil-fueled counterparts:

The rise of extreme weather

The world is getting warmer. According to recent data from NASA and NOAA, our planet was about 1.1° C warmer in 2021 than the late 19th century average. The results have been catastrophic. Forest fires, floods, hurricanes and severe storms caused more than $104 billion in damage and claimed more than 650 lives in 2021, according to The Washington Post. Fire-declared disasters affected more than 13% of the population in 2020 and more than 15% in 2021.

Weather-related disasters also cause major electrical disturbances. For example, Hurricane Ian, which struck Florida in late September 2022, knocked out power affecting 2.7 million people across the state. Likewise, 1.2 million people lost power in 2021 when Hurricane Ida swept through Louisiana. Winter storms have proven equally devastating. Winter Storm Uri caught Texas off-guard in February 2021, causing electricity outages for 4 million people.

Major electrical disturbance events

Figure: Data from (Ericson, S. J., & Olis, D. R. (2019). A comparison of fuel choice for backup generators (No. NREL/TP-6A50-72509). National Renewable Energy Lab.(NREL), Golden, CO (United States))


The growing need for backup power

With our nation’s electrical grid under frequent assault by increasingly intense storms, many businesses are turning to backup generators for uninterrupted power supply. This is especially true in vulnerable coastal areas and inland tornado alleys.

In a somewhat ironic twist, businesses are using diesel-powered generators, which produce emissions that contribute to climate change, resulting in extreme weather and power disruptions.

A study from M.Cubed, an economic and political consulting group, shows that the number of backup generators increased 34% in the Bay Area Air Quality Management District from 2018. Likewise, the South Coast Air Quality Management District saw a spike of 22% from 2020.

The majority of these generators are diesel powered. Collectively, they produce:

  • 86,899 metric tons of carbon dioxide
  • 20 metric tons of fine particulate matter
  • 62 metric tons of volatile organic compounds
  • 1,000 metric tons of nitrogen oxides

Propane-powered generators: A cleaner alternative

Put simply: we need a cleaner alternative to diesel-powered generators. Thankfully, the technology already exists. Generators that operate on propane have proven to be environmentally friendly relative to diesel.

Tailpipe emissions from propane generators are significantly lower in two air-pollution categories: NOx and PM (see charts below). While propane produces more CO2 emissions, that might not be the case for long. Currently, gas engines in backup generators are not optimized for propane, hence the higher CO2 output, but propane has potential to outperform diesel as a cleaner source with some modifications. For example, a backup power generator with a dedicated propane engine could produce 11-13% fewer CO2 emissions compared to diesel. PERC is presently working with two manufacturers to develop backup generators that achieve near-zero exhaust emissions.

Propane vs. Diesel Backup Power: an emissions comparison


CHP: The other backup power

Combined heat and power (CHP) systems are another clean-energy alternative to diesel-based backup power. This energy-generating technology not only supplies electricity but also building heat, hot water and/or cooling in commercial and industrial settings. It can be a building’s primary source of power and heat and serve as a backup during grid disruptions. Propane fuels several CHP solutions in the 1 kW to 1 MW range, converting more than 80% of fuel to electricity and heat.

How CHP works

Propane’s growing role in microgrids

Microgrids provide a decentralized and distributed energy resource for buildings seeking partial or total grid independence. These systems use a combination of solar panels and energy storage with backup power generation either supplying the facility or for charging the batteries – or both in some cases. According to the U.S. Department of Energy, there are about 461 microgrid installations in the U.S., most of which are grid connected with diesel-powered backup generators. Clean-burning propane, however, is making significant inroads into the microgrid market. For example, BoxPower supplies containerized microgrids using solar photovoltaic with battery backup combined with supplemental propane gensets. Electric utilities are deploying such systems to remote, wooded locations as alternatives to transmission lines, which have been known to spark wildfires.



WATCH: Microgrids partially powered by propane can provide rapid, renewable energy anywhere. BoxPower participated in a pilot project in that’s providing shelter for 25 families in San Jose. A solar-powered microgrid system with two 35kW propane generators supplies electricity and heating for this 100-bed community.

Air quality: An equity concern

Clean air shouldn’t be a privilege. Unfortunately, low-income neighborhoods tend to have higher exposure to air pollutants. A study by the Regional Equity Atlas, a joint project of 1000 Friends of Oregon, Ecotrust and Futurewise , brings this disparity into sharp relief. A map of the Portland metro region illustrates the overlap between high concentrations of air toxins and schools with high percentages of students eligible for free or reduced-price lunch. Not surprisingly, many of these schools are located near busy roadways. However, industrial emissions also contribute to poor air quality, as well.

Air Quality in Relationship to Percent Students Eligible for Free or Reduced Price Lunch, Freeways and Arterial Streets


Closing thought

While propane backup generators wouldn’t solve the air quality problem, they’d be a step in the right direction. Nor can we expect propane backup generators to fix climate change, but at least they won’t actively contribute to it when they kick on during the next storm.

To learn more about how commercial generators can keep your business operating during power disruptions, check out the following resources: