Infrastructure conglomerate Keppel has taken a final invesment decision to build a 600MW “hydrogen-ready” natural-gas power plant in Singapore that it claims could one day run on 100% H2, but the company has given no indication as to when it intends to make a switch from CH4 to H2.

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The Singaporean company will initially power the Keppel Sakra Cogeneration Plant using 100% natural gas upon completion in 2026, but claims that the combined-cycle plant “is also designed to operate on fuels with 30% hydrogen content and has the capability of shifting to run entirely on hydrogen”.

However, Keppel has not revealed any plans to actually use hydrogen at the site, and questions remain over whether such a move would be commercially viable.

To begin with, the Mitsubishi JAC-series gas turbines being installed at the power station can only cope with a hydrogen mix of up to 30%, so these would need to be replaced to enable higher proportions of H2 to be burned.

But with utility-scale combined-cycle gas turbines costing as much as $1m per MW — and potentially even more for a 100%-hydrogen turbine — such a retrofit would seem unlikely any time soon, especially given the high expense of the initially installed turbines, and the fact that 100%-hydrogen turbines are not yet commercially available (see panel below).

And due to the lower energy density of hydrogen compared to natural gas — and the massive energy losses associated with producing, transporting and storing the cleaner fuel — any use of H2 would inevitably result in far more expensive electricity.

Hydrogen turbine progress

Some manufacturers are making progress on developing pure-H2 turbines.

For instance, construction equipment specialist Caterpillar has developed kW- and single MW-scale turbines that run on pure hydrogen for its designed-to-order power generators, and Kawasaki is currently working on an 30MW experimental pure-H2 power generation demonstration project with Germany’s RWE.

But on the scale required by a large power station there is still some way to go. Mitsubishi and US engineering firm GE are both working on developing a utility-scale turbine that can burn 100% hydrogen, but it is estimated that it will take three to four years for the technology to come to market.

Siemens also plans to commercialise a pure-hydrogen turbine by 2030.

The use of hydrogen or, indeed, ammonia for power production is therefore expected to be fairly limited worldwide — and in most cases would be used as peaker plants to top up the power supply at times when the wind isn't blowing and the sun isn't shining.

However, Keppels Sakra power station is a combined-cycle gas-turbine facility designed for baseload generation, rather than the cheaper-to-build open-cycle plants that are typically used as peakers.

Nevertheless, Keppel took final investment decision on the facility this week and plans to bring it on line by the end of June 2026 in the Sakra area of Jurong Island, Singapore, at a cost of S$750m ($540m).

The company has not given any timeframe for burning any hydrogen in the turbine, how it plans to source the fuel and whether it will be renewable or fossil-derived. The company was not available to answer questions from Recharge at the time of writing.

The rationale for building the Singaporean plant at a time of sky-high natural gas prices — Asian gas prices recently hit levels not seen since March when Russian started its invasion of Ukraine — appears to be rooted in system reliability.

Decarbonisation pressures may also play a role. Singapore does not have much in the way of renewable energy resources, and the government has recently raised its climate ambition to reach net zero by 2050.

Keppel may be using the hydrogen-switching option in an attempt to future-proof itself against rises on Singapore’s carbon tax regime, which the government is expected to ratchet up to $50-80 per tonne by 2030, from $5 per tonne today.

Separately, Keppel announced it had signed an MoU with Mitsubishi to carry out a feasibility study on a the development of a 100% ammonia fuelled power plant at a site in Singapore. This is the second such deal signed by Mitsubishi in Singapore recent weeks: earlier this month it brought Japanese power behemouth JERA in on a plan to build a demonstration power plant that will burn 100% ammonia in the city-state’s Jurong Port.

Efficiency savings

Even so, the Sakra Cogen plant’s streamlined efficiency will save up to 220,000 tonnes of carbon dioxide per year versus the average efficiency of a Singaporean power plant, Keppel said.

As a result, the announcement was welcome by the island city-state’s energy regulator.

“Singapore’s electricity demand is projected to grow with increasing electrification and economic growth,” said Ngiam Shih Chun, chief executive of Singapore’s Energy Market Authority. “Being hydrogen-ready, this power plant by Keppel will contribute towards greater efficiency and lower carbon emissions. This will support Singapore’s transition to a more sustainable energy future while ensuring the security and reliability of electricity supply to consumers.”