Data Desk

Propane, the Forgotten Cheap BTU

While the rest of the plant's energy bill climbed, the fuel in the forklift tank quietly became the cheapest BTU on the floor. Here is what the benchmark says, and how to make the delivery invoice reflect it.

Walk the fence line behind most plants and you will find it: a white tank on legs, or a cage of cylinders by the dock door, feeding the lift trucks and the winter heaters. Nobody inside owns that line item the way they own electricity or diesel. The tank sits there, the truck tops it off on a schedule, the invoice auto-pays. Which is how the one energy input that actually got cheaper slipped past the whole building. Propane traded at $0.66/gal as of Aug 7, 2026, according to the Energy Information Administration's benchmark spot series, down 40.9% from $1.12 at year-end 2021 and holding in the cheap end of its archive. Across those same five years, nearly every other line on a plant's energy bill moved the other way.

The benchmark behind the tank

The number is the spot price of propane at Mont Belvieu, the storage and trading hub on the Texas Gulf Coast where American propane is priced. It is a wholesale figure, dollars per gallon, before trucking, tank rental, and dealer margin, so it is not what the delivery invoice says. It is the number the delivery invoice is built on, which makes it the number to negotiate from. The archived history behind this chart opens in May 2021, and against that history the current print sits at the 13th percentile, below 87% of everything the archive holds. The shape of the ride matters as much as the level. The series touched $1.61 on March 7, 2022, in the repricing that followed Russia's invasion of Ukraine, then collapsed to $0.53 by July 3, 2023. Today's price sits 58.9% below that high.

Propane spot price, Aug 7, 2026 (EIA): $0.66/gal. The archived range runs from $0.53 on July 3, 2023 to $1.61 on March 7, 2022. The current print sits at the 13th percentile of readings since May 2021.

Why the cheap BTU got cheap

Propane's cheapness is structural, and that matters for whether to trust it. Nobody drills for propane. It arrives as a byproduct wherever natural gas is processed and crude oil is refined, which means supply is set by the drilling economics of other molecules entirely. When producers chase gas or oil, propane shows up whether the market wants it or not, and the surplus has to clear through exports or through price. Demand, meanwhile, is lopsided: rural heating in winter, crop drying in the fall, and a steady industrial base of lift trucks, temporary heat, and process burners the rest of the year. A fuel whose supply follows someone else's business plan and whose demand peaks a few months a year tends to spend its summers cheap and its shocks sharp. The March 7, 2022 spike was the sharp part. Most of the time since has been the cheap part.

That divergence is the story. The five-year window that took propane down 40.9% is the same stretch in which plants watched power rates, diesel surcharges, and nearly every processed input climb. A cost line moving opposite to everything around it is rare, and rare things get missed, because every cost review is built to hunt increases. Nobody schedules a meeting about the line that went down. That is precisely the line where money is sitting.

The forgetting is the operational problem. Electricity gets a line in every machine-hour rate. Diesel gets a fuel surcharge clause with its own paragraph in the freight contract. Propane, at most plants, gets an auto-delivery agreement signed years ago and renewed by silence. Dealers price delivered propane as the benchmark plus a margin, and when the benchmark falls, that margin has a way of widening quietly to absorb the difference. A benchmark down 40.9% since year-end 2021 only saves money if somebody checks the invoice against it.

A benchmark that fell only saves money if somebody checks the delivered invoice against it.

The forklift math

Put numbers on a common case. A plant runs 8 propane lift trucks across two shifts, each truck burning through about 8 gallons of fuel per shift, 250 operating days a year. That fleet consumes 32,000 gallons annually. At the current benchmark of $0.66/gal, the fuel itself prices out at $21,248 a year. At year-end 2021's $1.12, the same gallons cost $35,936. Had the March 7, 2022 high held, they would have run $51,680. The benchmark move since year-end 2021 is worth $14,688 a year to that one fleet, before anyone changes a single operating habit.

Two honest caveats. Delivered price runs above the benchmark, because trucking, tanks, and dealer margin are real costs, so the dollar figures above understate the actual bill. And the swing is computed at benchmark, meaning the $14,688 is what should have flowed through if the dealer's margin held constant. If the delivered rate on the last invoice has not fallen roughly in step with the spot series on this page, the difference did not vanish. It moved into someone else's margin.

What to do with the number

Three moves, in order of effort. First, pull the last year of propane invoices and divide dollars by gallons, then set that delivered rate's path next to the chart above; the spread between the two lines is the negotiation. Second, reprice the contract. Dealers will index delivered propane to the published benchmark plus a fixed margin for accounts that ask, and an account that has ridden an unindexed rate through a 40.9% benchmark decline is exactly the account that should ask. Third, let the cheapness inform equipment decisions while it lasts. A fuel sitting at the 13th percentile of its archive changes the arithmetic on propane versus electric lift trucks, on temporary heat for the winter, and on any burner that could take either fuel, and that arithmetic belongs in a calculator, not a gut call. The number will not stay forgotten forever. The plants that reprice against it now are the ones that will have banked the cheap years.

Put your fleet's fuel burn, your delivered rate, and this live benchmark into the power cost calculator to see what propane actually costs per hour of runtime. Run your own numbers

Published 2026-08-18.