AN INDUSTRIAL PLANT, NOT A POWER STATION

89.6% CAPACITY FACTOR, without gas backup

Industrial Facility

People often describe a green ammonia plant as renewable generation with an electrolyser attached. That description is incorrect, and it explains why so many announced projects fail to reach a final investment decision. An ammonia plant is an industrial facility, two numbers govern its economics above all else: the capacity utilisation factor of the electrolyser and the capacity utilisation factor of the Haber-Bosch synthesis loop. These are the two most capital-intensive assets on site, and every percentage point of utilisation they lose spreads the same fixed capital across fewer tonnes of product. Get both working hard, around the clock, and the levelised cost of ammonia falls into competitive territory. Let either one sit idle chasing variable renewable output, and no amount of cheap power will rescue the project.

Why that one number decides everything

A gas-fired ammonia plant’s cost is dominated by feedstock, so its economics track the gas price. A green plant has almost no fuel cost. Its cost is the capital sunk into the electrolyser, the synthesis loop, the hydrogen chain and the generation behind them, divided by the tonnes it produces – and tonnes produced scale almost directly with capacity factor.

The consequence is stark. A plant held at 50% carries close to double the capital cost per tonne of the same plant held near 90%, because the same fixed assets are spread over little more than half the output. For green ammonia, capacity factor is the master variable in a way it never is for gas.

The number, and its benchmark

The Boolathana platform reaches an 89.6% synthesis-loop capacity factor. That sits inside the 88 to 93% availability band of conventional gas-fired ammonia plants – the range a plant with a pipeline behind it achieves. Boolathana reaches it because the resource is firm before storage is added, not because storage is doing the work.

The first reason - the resource is firm before storage is added

Wind at Boolathana is night-dominant. It averages roughly 1,740 MW overnight against about 920 MW at midday – nearly twice as high – and around two-thirds of its energy arrives in hours when solar is producing nothing – being 49.1% of all hours.

The two resources are anti-correlated at −0.24. The combined profile never approaches zero, because wind alone holds the overnight floor. The Resource sets it out in full.

Storage and dispatch can refine the shape of an energy resource. They cannot affordably manufacture a capacity factor the resource does not support. The resource sets the ceiling; the plant design reaches up to it.

The second reason - the electrolyser is deliberately oversized

The instinct is to match electrolyser capacity to renewable capacity. Running the full hourly dispatch across a grid of sizes shows that a larger electrolyser produces a materially better outcome. When generation peaks, a generation-matched electrolyser cannot absorb the surplus and it is spilled. A larger one turns energy that would have been wasted into hydrogen, and then into ammonia, accepting a lower capacity factor on the electrolyser itself to do it. That is productive reserve, not idle capital.

The same modelling showed the optimum is a flat basin rather than a knife edge. The design does not depend on hitting a single sizing point, and it tolerates the movement that vendor selection and FEED will bring.

Storage sized to its job

Once the electrolyser absorbs the generation peaks, curtailment is already low, so the battery adds little to production. It is sized for ride-through, and the dispatch modelling led to a smaller battery than the original configuration carried, not a larger one.

GGE sizes the hydrogen store for endurance rather than for capacity factor.

No gas in the base case

The plant rides through the worst event in the record on stored energy alone, with margin, and without gas.

A combustion fleet sized to keep the process load running would add capital and maintenance, consume saleable ammonia or gas as fuel, and run for a negligible fraction of the year against an event the storage already covers. GGE excludes it from the base dispatch case by design.

This concerns process-load backup only. The plant carries the essential-services backup any industrial facility requires – black-start capability, meaning enough generation to restart the plant from a complete shutdown, uninterruptible power for controls and safety systems, and firewater supply. Those are retained.

Against a conventional plant

Conventional plant figures are industry reference values. Boolathana figures derive from hourly dispatch modelling over 61,368 hours of site-calibrated resource data, 2016 to 2022. Items subject to vendor and FEED confirmation are identified on this page.

What is proven, and what is not

The dispatch outputs are proven across the full hourly model, calibrated to the validated base case. Plant and storage sizing are dispatch-proven and carry forward to FEED engineering.

Items remain to be confirmed. Electrolyser specific energy consumption awaits vendor confirmation. Certain synthesis-loop operating assumptions are carried to vendor and FEED confirmation. FEED will confirm absolute annual output though the sizing that produces it is robust.

GGE states what its cost figures include – generation, firming, water, export and the synthesis process – rather than quoting a favourable subset. The architecture and cost modelling behind this are available to qualified counterparties under NDA.

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