The world’s advanced economies have committed to phasing out coal over the next seven years. But not Japan, which is alone in pushing that it can make coal less harmful to the planet.
Nowhere is this more evident than at the country’s largest coal-fired power plant in Hekkinen, a small town in central Japan, where 400,000 tonnes of jet-black piles are spread over a plot the size of 40 football fields.
Starting next spring, Jera, the company that owns the site, wants to demonstrate that it can blend ammonia – which does not emit carbon dioxide when burned – with coal in its boilers. The use of this new technology is sparking debate about whether it is better to find cleaner ways to use coal, or to phase it out sooner in favor of renewable energy.
The company says the ammonia method could reduce dangerous emissions in the fight against global warming. In an effort initially conceived and heavily subsidized by Japan’s government, it is one of several power companies planning to use ammonia in a process marketed as “clean coal”.
With ammonia, companies can “use the plants we have instead of building entirely new plants,” said Katsuya Tanigawa, general manager of JERA’s Heikinen site.
Japan gets about a third of its electricity supply from coal, one of the world’s dirtiest sources of energy. But critics say that using ammonia only increases Japan’s dependence on fossil fuels and that ammonia production could potentially increase carbon emissions. Burning ammonia can also produce nitrogen oxides, which are toxic to humans and are another emission to be managed.
“We need to reduce emissions from coal power plants now, not invent a technology that may or may not be possible,” said Katrin Petersen, senior policy advisor at the think tank e3G.
Energy concerns have risen sharply in Japan since the earthquake and tsunami in 2011 caused three failures at the Fukushima Daiichi nuclear power plant. In the immediate aftermath of the disaster, Japan shut down all of its nuclear plants, shutting down 30 percent of the country’s electricity supply overnight. To compensate, the country’s power companies rushed to build new coal plants while the world was moving away from fossil fuels.
Japan’s prime minister, Fumio Kishida, recently stepped up efforts to restart the country’s nuclear power network, but the communities hosting the plants have resisted.
Japan, the world’s third largest economy, has very few natural resources of its own, and can generate only 11 percent of its energy needs without fuel imports. One of the lowest self-sufficiency rates among the world’s wealthiest countries.
At a meeting of environment ministers from the Group of 7 leaders in Sapporo this spring, Japan was the only country that refused to commit to bringing its coal use down to net zero by 2030.
The government and the country’s power industry point to several obstacles to a quick build-out of renewable energy sources, including Japan’s geographic isolation, mountainous terrain, deep ocean waters and the annual typhoon season.
Along with China, which President Xi Jinping recently said would follow through on its “pace and intensity” of carbon emissions cuts, Japanese officials say their country too has its own timetable and methods.
“We want to go from the same mountain to the same peak,” said Atsushi Kodaka, director of the energy strategy office at the trade ministry. “But our climbing route should not be the same as everyone else’s.”
The power industry is also reluctant to give up coal because it has recently spent heavily on building new plants. Since 2011, Japanese power companies have built 40 coal plants – about a quarter of Japan’s total coal-fired network – with a new Jera plant coming online last month.
Together with industry, the Japanese government has contributed approximately 152 trillion yen (about $1.1 trillion) over 10 years to help the country achieve net zero carbon emissions. The trade ministry says that by 2030, coal-fired generation will be down to 19 percent of electricity supply, with ammonia technology accounting for about 1 percent, and this is likely to increase.
Jera knows she has to convince a potentially skeptical public of her plans, and so she is running ads in cinemas and offering discount coupons that promote her efforts to develop “zero-emission thermal power”.
Japan also hopes to eventually export the technology to its neighbors in Asia, where it has helped build new coal plants in recent years.
“We are trying to reduce dependence on coal in such countries,” said Masashi Watanabe, natural resources and energy planner at the trade ministry. “Ammonia co-firing could be a solution.”
In Hekkinen, welders recently secured the top of a 700-tonne storage tank at the massive Jera plant. Several large orange pipes lay strewn on the ground, waiting to be fitted into the pipeline that would transport ammonia to the plant’s boilers.
During a recent test, the company mixed a mixture of 0.02 percent ammonia with fist-sized pieces of coal in a boiler heated to temperatures of more than 1,500 °C, 2,700 °F. Fulfilling its next target will be a big challenge.
By March, the company wants to start testing a mixture made of 20 percent ammonia, becoming the first in the world to do so.
Even if the technology works, obtaining a stable, cheap, and clean supply of ammonia could put considerable pressure on the world’s supply of the compound, which is needed to produce fertilizer.
government’s own green growth strategy acknowledges that if all Japan’s coal-fired plants used 20 percent ammonia, “they would need about 20 million tons of ammonia per year”—the equivalent of the entire amount of ammonia currently traded on the world market.
Such supply constraints make it “virtually impossible” to execute the ammonia plan, said Hajime Takizawa, a climate and energy researcher at the Institute for Global Environmental Strategies, a government-funded, independent research group. However, the government says that once it is proven that the technology works, suppliers will meet demand.
But producing ammonia requires electricity, which under current methods is usually generated from fossil fuels such as coal or natural gas. In a typical process, water is heated to extremely high temperatures – 2,000 °C or 3,632 °F – so that hydrogen atoms are split and combined with nitrogen. (See your high school science textbooks for the chemical formula of ammonia!)
Heating that water requires a lot of electricity, and the supply of ammonia that will initially flow to Japan will likely be made using so-called gray or brown electricity. So while burning ammonia in a power plant reduces carbon emissions at one location, making ammonia can generate more carbon emissions at another location.
As a result, the ammonia method “has very little mitigation potential,” said Masayoshi Ioda, Japan team leader for the climate activist group 350.org.
Suppliers say they will eventually use renewable energy to make ammonia or capture the carbon emitted during the production process and bury it in the ground. Given the cost of such methods, analysts say, mixing ammonia and coal will be more expensive than using renewable energy such as wind power directly.
Ultimately, critics say, Japan is prioritizing ammonia technology to protect strong industrial interests against new renewable energy suppliers. “They are acutely aware that they are the losers in this change,” said Kimiko Hirata, founder of the research and advocacy group Climate Integrate. “So they’re really big into protecting the status quo and vested interests for as long as possible.”
