The dream of a carbon-free fuel is driving an investment boom in hydrogen and ammonia projects. Japan, for example, has pledged to reduce its emissions in line with the Paris Agreement by 2050, and plans to generate 10% of its energy needs using hydrogen and ammonia by then.
For Japan, the potential of using these fuels to generate electricity is appealing. As an island country, Japan has limited space for wind and solar farms, and is surrounded by deep waters that make importing electricity by cables difficult. Meanwhile, the 2011 earthquake that caused a nuclear plant meltdown in Japan forced a turn away from nuclear energy. The country currently depends on oil, gas, and coal imports to power its economy, contributing to it being the the fifth largest emitter of greenhouse gases, according to the World Bank.
On Jan. 7, JERA, Japan’s largest power company and producer of more than 10% (pdf, p. 16) of the country’s emissions, announced that it would spend nearly $600 million to develop ammonia technologies, with 70% of the money coming from the government’s climate innovation fund.
When burned, hydrogen emits only water vapor and warm air. Ammonia, which is made using hydrogen, but is denser and easier to transport, likewise emits no carbon during combustion. It does emit nitrous oxide (more familiarly encountered as laughing gas) a greenhouse gas 298 times more powerful than CO2, though these emissions can be captured before they’re released into the air.
But ammonia’s green sheen may not translate to a better way to produce electricity for Japan.
Two demonstration projects, which will scoop up $392 million of the funding from JERA and the Japanese government, plan to convert existing coal-fired power plants to using a combination of ammonia and coal, aiming for a 50% split between the two fuels by 2029.
In a post on LinkedIn, Paul Martin, a co-founder of the Hydrogen Science Coalition, which aims to inform public investments, called the ammonia-coal projects “wasteful greenwashing” that will squander the energy that goes into producing ammonia. Martin has been sounding the alarm about the hype around hydrogen as a fuel as more industries buy into the idea of a hydrogen economy that will make carbon emissions vanish for industries as wide-ranging as steel, aviation, and two-wheeled vehicles.
“The use of ammonia as a fuel is possible, but for stationary applications like power plants to be used more than occasionally as an emergency backup fuel, it’s highly questionable. Feeding it as a co-feed to inefficient coal plants? That’s just crazy.”
According to Recharge, a trade publication for the renewable energy industry, it takes 14.38 megawatt-hours (MWh) of energy to produce one metric ton of green ammonia. Burning that ton produces 5.16 MWh of electricity for consumption—a third of what it took to make it. Use the ton of ammonia in a coal-fired plant, and that drops even further, to 1.96 MWh, “making it an incredibly inefficient method to produce electricity,” writes Recharge.
JERA declined to comment directly on Recharge’s calculations. However, Atsuo Sawaki, a spokesperson for JERA said that, “The thermal power generation plants that JERA aims to introduce ammonia are highly efficient, and JERA believes that the power generation efficiency will not be lowered by ammonia co-firing.”
Sawaki adds that the project is not greenwashing because JERA intends to use blue ammonia in the coal plants.
At present, producing ammonia, which is mostly used for fertilizer, is an energy-intensive process that contributes heavily to global emissions. This is “grey,” ammonia, which is made from hydrogen produced using fossil fuels. That is why scientists and engineers are first looking at ammonia’s potential as a carrier for other zero-emissions fuels, such as hydrogen, or for specific uses such as shipping—rather than using it as a fuel at the kind of scale that power plants would require.
For one plant where it’s already carried out a demo, JERA is expecting to have to source about 40,000 metric tons of ammonia in the next four years. The Japan Times estimated that if all of the country’s power plants were to shift to ammonia for 20% of their needs, Japan would require 20 million tons of ammonia—about 20 times what the country uses now. Japan presently imports about 20% of its ammonia, currently made from fossil fuels, from Malaysia and Indonesia. It is also looking at sourcing blue ammonia from Saudi Arabia for power generation.
Blue ammonia is made with the same process as grey ammonia, with hydrogen made from using fossil fuels, but in this case the carbon dioxide emissions are captured and stored during the process rather than being released into the air. There’s a lot of skepticism about the green credentials of blue hydrogen—and therefore the green credentials of ammonia made from it—because of low capture rates and other issues. Captured carbon likewise raises challenges about what to do with and how to store carbon, and Saudi Arabia’s blue ammonia project looks set to beget more carbon emissions. Aramco, the oil company generating some of Japan’s blue ammonia, plans to use some of the carbon it captures to extract more crude oil from its fields.
Green ammonia, a truly zero-carbon fuel, is made from hydrogen that is produced using renewable energy, and so far only produced in tiny quantities, mostly in labs and pilot projects. The power firm is also looking at developing ammonia synthesis technologies, presumably greener ones, but for now these projects will have to rely on ammonia made in ways that generate emissions. JERA says they will consider using green ammonia if the price falls below that of blue ammonia.