Fuel for thought

How work at the Fukushima Hydrogen Energy Research Field is paving the way for a renewable-fueled future

“Global warming could easily be solved if we all stopped using energy,” says Eiji Ohira. “If we stopped moving around, going on trains, cars, using electricity, and went to bed when it got dark at 8pm... We could go back to the Edo period [1603-1868].”

Ohira, it must be emphasised, is not recommending such a strategy for tackling climate change. As director general of the Fuel Cell and Hydrogen Group at the New Energy and Industrial Technology Development Organization (NEDO), he’s interested in rather more sophisticated solutions to the challenges of moving to a renewables-fueled, net-zero future.

One of the biggest of these challenges is energy storage. Solar and wind power plants are becoming ever more efficient, but when the sun doesn’t shine and the wind doesn’t blow they are useless. Conversely, if the sun shines too brightly and the wind blows too hard when electricity demand isn’t high, excessive production can end up overloading power grids. One extreme leads to blackouts, the other to breakdowns.

Power-to-gas technology

Happily, Ohira and his team of engineers are now working on technology that could help iron out the peaks and troughs in energy delivery, to make renewables dependable. “As a method of tackling the difficulties associated with our transition to renewable energy, the concept of ‘power-to-gas’ has started to be explored around the world, especially in the context of converting excess electricity into hydrogen,” says Ohira.

What’s the big idea?

The concept is simple: when you have excess capacity in renewable energy – at particularly windy or sunny times – you can use it to create hydrogen (see infographic for details). This then acts as stored energy which can later be used in hydrogen cells, delivering emissions-free electricity to vehicles, homes, offices or city streets. “If there is a big difference between the amount of power generated and demand in summer and winter, electricity should be stored during periods when plenty of it is generated, and used in other seasons,” says Ohira. “And when it comes to using energy, hydrogen is better than storage batteries.” Ohira’s group has set off down the path of making power-to-gas into a workable reality. “In 2016, we determined that there was a need for a technological development project aimed at building a ‘hydrogen energy-based society’ that is larger in scale than the one we had launched initially, and we accepted applications again under various themes,” says Ohira. “One of the companies that indicated their interest was Toshiba, which proposed to conduct research here in Fukushima in the future with us.”

And so it came about that in 2020, the Fukushima Hydrogen Energy Research Field (FH2R) was launched. Its aims were not just to develop the technology behind power-to-gas, but also research the business model behind it. “We saw a need to develop a system equipped with a water electrolysis apparatus running on 10 megawatts that is capable of producing 2,000 cubic meters of hydrogen per hour,” says Ohira. Fukushima was chosen in part because the prefecture aims to generate at least 100 percent of its energy demand from renewable energy sources by around 2040. “This would probably result in a large influx of renewable energy into the energy grid of Fukushima prefecture eventually, which would make any issues associated with grid constraints apparent before the rest of Japan, even if such issues were to be localized in Fukushima,” says Ohira.

The process begins with water. “NEDO basically uses Japanese tap water as the water itself, and puts it through a purification system,” says Ohira. “This removes impurities such as chlorinated lime. In electrolysis, you simply select an electrode, add it to the water, and let the electricity flow, which releases oxygen and hydrogen. For this system, hydrogen is generated in a purely alkaline solution, specifically a liquid in which potassium hydroxide is added to make it easier for ions to pass through.”

Becoming carbon-neutral is not something that can be done in one fell swoop

Hydrogen Infographic

Scaling up

The success that the FH2R system has had in producing hydrogen at speed is, says Ohira, “unprecedented worldwide”. But it’s just the beginning – FH2R is still on an experimental rather than a practical scale, and the 10 megawatt system will eventually have to lead to much bigger versions. “Our goal is to have six gigawatts of water electrolysis by 2025 and 40 gigawatts by 2030,” says Ohira.

Scaling up is only part of the picture. ”Since we are assuming that it will be an energy base, it would be troublesome if there are disruptions, so we need to develop technology to maintain reliability,” says Ohira. “On top of that, we will need to work out the cost. How much will the initial cost, operating cost, and maintenance cost add up to, and will the operation consume fewer resources and reduce energy consumption? In the future, there will be a lot of things to address, such as challenges to cost efficiency, policies like special incentives for using hydrogen cells, and compatibility with smart power grids. I think we need to clarify those sorts of things.”

The team has run small-scale tests to see how their output will fit into the whole new hydrogen ecosystem. “We have had hydrogen transported to the Azuma General Agricultural Park in Fukushima city to J-Village, and to the Roadside Station in Namie town, and used there,” says Ohira. There is another, more high profile, potential use on the horizon too. “We were planning to use large amounts of hydrogen at the summer Olympics venues,” says Ohira. In the original plan, hydrogen from FH2R was going to be utilized as fuel for the ceremonial Olympic Cauldron featuring in the Games’ opening and closing ceremonies, and provide official fuel cell vehicles to transport competitors and officials between events. “Unfortunately, the Games have been postponed due to the COVID-19 pandemic,” he continues. “We hope that the rescheduled Games can still be a showcase for a hydrogen-based society.”

The future of power

In order to expand the field of power-to-gas operations, Ohira says an international approach is needed. “We do need to work together with others,” he says. “The hydrogen field is gaining a lot of momentum overseas, and I hope we can work with one another to advance our understanding of its potential.”

However, while power-to-gas at FH2R is a groundbreaking project with global potential, it’s not the only way that NEDO is helping to address the challenge of net zero. “Another initiative undertaken by NEDO is Carbon Capture Utilization & Storage (CCUS), which involves capturing the carbon dioxide emitted when fossil fuels are burnt and reusing it as a carbon resource,” says Ohira. “We also engage in carbon recycling and eco-friendly initiatives, as well as energy conservation, renewable energy and smart grid technologies. There’s no silver bullet when it comes to net zero,” says Ohira.

“Becoming carbon-neutral is not something that can be done in one fell swoop,” he concludes. “We need to look at combining a lot of different options and integrating a number of different technologies to realize the energy systems of the future.”