By Byron Raal, Founder and Editor, Compressed Air Solutions

Ask an Australian manufacturer where their decarbonisation budget is going and you will hear about solar, electrified heat and fleet. Ask them when their compressed air system was last audited and you will usually get a blank look. That gap is costing them, because compressed air is one of the cheapest sources of industrial emissions abatement in the country, and it is sitting in plain sight.

Compressed air is often described as the fourth utility. Most industrial sites run it, few meter it, and it is one of the largest single electricity loads in a typical plant. Every kilowatt-hour it wastes is scope 2 emissions bought at retail prices for no productive output.

And it wastes a lot. In plants that have never been audited, 20 to 30 per cent of the compressed air being generated is typically lost to leaks before it does any useful work, a figure that comes from US Department of Energy assessment data and holds up in Australian plants. A single 3 mm leak in a distribution line wastes over $3,000 a year in electricity at single-shift running and 30 cents a kilowatt-hour, and the emissions that go with it. Leaks are silent, invisible and cumulative, which is why they survive for years while the sustainability report goes looking for savings everywhere else.

The abatement economics are hard to beat. Plants that audit and fix their compressed air systems for the first time routinely cut that system’s energy use by 20 to 35 per cent, and the work typically pays for itself inside one to two years. The fixes are unglamorous: repair the tagged leaks, bring set pressure down to what the plant actually needs, switch the compressor off when production is off, and put controls on multi-compressor systems so they stop fighting each other. No new generation assets, no offsets, no certificates. Just less electricity for the same output, which is the definition of abatement that also improves the bottom line.

There is a second course hiding behind the first. Most of the electricity a compressor draws leaves it as heat, and a large share of that heat is recoverable for space heating, process hot water or boiler feed preheat. In most Australian facilities it is vented to the sky. For sites burning gas for low-grade heat, compressor heat recovery is a direct gas-displacement play, and it comes from equipment the site already owns.

For sustainability managers, the practical path is short. First, give compressed air its own line in the energy accounts; what is buried in “plant power” cannot be managed. Second, run a leak survey, or simply meter the system over a shutdown weekend, because whatever the compressor feeds when nothing is running is pure waste. Third, get a proper audit (how a compressed air energy audit works: https://compressedairsolutions.com.au/resources/energy-audit/) before committing capital, so the fixes are sized on measurement rather than guesswork. If you want to see what your own leaks are costing before you do anything else, a leak cost calculator: https://compressedairsolutions.com.au/tools/leak-cost-calculator/ will turn hole sizes and hours into dollars and kilowatt-hours in about a minute.

Australian industry does not lack decarbonisation ambition. It lacks attention to the unglamorous systems where the cheap abatement lives. Compressed air is the place to start, precisely because nobody is looking at it.

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