GreenCars 101

Red Hydrogen: How It Works

Dave Nichols
Jul 2023
Scientists in Japan are pushing forward with a new technology called red hydrogen. The process generates both nuclear-powered electricity as well as clean hydrogen - opening the door for even more zero-emissions vehicle options. But many challenges still remain.
Home hydrogen storage concept

Nuclear-Generated "Red Hydrogen"

The increasing number of electric vehicles on the road is paying real dividends in reducing the carbon emissions from burning fossil fuels. However, generating that electricity - and supplying enough of it to electric grids to support the electric cars out there - will start to become an issue as even more EVs fill our roads. Plus, in order to truly have a green car, the electricity that powers it as well as your home, needs to come from a clean, carbon neutral source.

Currently, much of the electricity in the world is created through the conversion of coal or natural gas - and these methods of creating electricity are far from clean. However, an innovative new process out of Japan may point to a possible solution to our future energy conundrum. It uses hydrogen - and not just any hydrogen, but what is known as red hydrogen, which is produced through the use of nuclear energy.

Japan is a world leader both in the production nuclear energy, as well as in hydrogen technology. There's a real hydrogen supply chain in Japan, and the country's automakers have developed and sold numerous hydrogen fuel cell electric vehicles. Fukushima Hydrogen Energy Research houses the world’s largest green hydrogen plant, as well, though clean hydrogen produced at the plant is very expensive.

With a national goal to reach carbon neutrality by 2050, Japanese scientists feel they're onto something, with red hydrogen created with nuclear power.

Indeed, after nuclear power, hydrogen has the highest specific energy density of any known fuel. It packs 33.3 kWh/kg - three times more energy that would be found in the same mass as the best fossil fuels. Hydrogen can be burned to generate heat or used in fuel cells to generate electricity, and, in both cases, the only thing released is water vapor, making the process carbon-free. However, because it is a gas, hydrogen must be compressed at very high pressures to make it practical. This makes storage and transportation challenging.

For these reasons and more, lithium-ion batteries have taken the lead as a cheaper alternative to hydrogen for powering electric cars. But many see hydrogen fuel cell vehicles as the best of both worlds, offering zero-emissions driving as well as the advantage of quick refueling. Legislators and automakers in the U.S. and Europe have placed their bets with battery technology, while Japanese automakers are taking a broader view - thinking that hydrogen fuel cell cars will be part of the ultimate mix.

Ultimately, both battery-electric vehicles and fuel-cell vehicles use electric motors - but in the former, power either comes from plugging your car in and recharging the batteries, while the latter uses hydrogen replenished at fuel stations.

Tokyo city lights

Japan Needs Energy

Japan is a very small island with enormous energy needs. Since the oil crisis in the 1970’s, Japan has favored hydrogen technology as a sustainable and reliable solution to generating electricity, in addition to its use of nuclear power.

Many  industries such as the steel, chemical, and heavy transportation sectors cannot run on electricity alone and require burning some kind of fuel. In cases such as these, hydrogen is a good alternative to fossil fuels. For instance, steel production accounts for nearly nine percent of total worldwide greenhouse gas emissions. A Swedish company named Hydrogen Green Steel (H2GS) plans to use hydrogen instead of coal to produce steel beginning in 2024. It will produce five million tons of high-quality steel per year with 95 percent fewer carbon emissions than traditional steel mills.

In heavy transportation such as sea-going freighters, the use of hydrogen could cut as much as 14 percent of our total carbon emissions and offer a big step toward carbon neutrality.

So what's the issue? While hydrogen burns cleanly, it is only as clean as the energy and processes we use to make it. And at the moment, 90 percent of the world’s hydrogen is made by burning fossil fuels.

tsunami evacuation sign

In the Wake of Disaster

Japan needs a stable supply chain to keep its hydrogen industry growing. Red hydrogen, produced from nuclear energy, may be the answer.

There is, naturally, some sensitivity in Japan around nuclear power. Just over a decade ago, there was a catastrophic nuclear disaster at the Fukushima Daiichi Nuclear Power Plant. Triggered by the Tohoku earthquake and tsunami, the plant suffered a critical meltdown and explosion of the reactor. Radioactive materials were released into the atmosphere, and hundreds of thousands of Japanese residents were displaced. The disaster also triggered many countries to reevaluate their nuclear plans, and many countries shut down nuclear power plants - for instance, in America, 26 of the 96 operational nuclear reactors have been decommissioned since 2011.

In Japan, a country leading the way in nuclear energy production, all nuclear reactors were shut down - and replaced by burning coal, oil, and natural gas to cover the national energy gap.

clean energy landscape with hydrogen, windmills, and solar panels

Next, Let's Look At HTGR

Skyrocketing oil and gasoline prices have prompted Japan to reconsider the use of nuclear energy. A new form of reactor called High Temperature Gas-Cooled Reactor (HTGR) offers some promising characteristics. Small-scale versions of these reactors have been tested since 1964, and could be the solution to cutting carbon emissions - making cleaner hydrogen a game-changer.

Nuclear reactors use fission energy from the breakup of heavy atoms like uranium or plutonium to generate heat. That heat is either used directly, or to boil water and drive steam turbines to generate electricity. This reaction needs a neutron to start but releases three other neutrons, which leads to a sustained chain reaction that produces heat and energy.

This form of nuclear reaction is difficult to control; heat must constantly be drained to avoid a meltdown. Most of the 440 reactors in operation on our planet are light water reactors that use liquid water as a coolant.

What's different about HTGR reactors is that they replace water with helium gas as their coolant. Helium can be heated to a much higher temperature than water, and since it is an inert gas, it also won’t corrode the reactor’s piping. The reactor can be operated at over 1,800 degrees Fahrenheit - compared to light water reactors, which typically reach 600 degrees. The heat generated can then be used to power heavy industrial processes directly.

One use of HTGR heat is the steam reforming process used to make hydrogen from methane and other components of natural gas. Using the heat from an HTGR reactor means hydrogen can be produced without using fossil fuels – although gas reforming does still produce carbon monoxide and dioxide as by-products of the chemical reactions. Overall, hydrogen production using HTGR-sourced heat reduces its carbon footprint by about 40 percent.

You can watch a popular video on Japan's breakthrough HTGR technology right here on YouTube.

male worker inspecting in a clean lab

Zero-Emissions Production with HTTR

There are other methods that don’t generate any carbon emissions at all, and which make the resulting hydrogen completely clean.

High-temperature steam electrolysis and the thermochemical water-splitting iodine-sulfur process are two ways that hydrogen can be made carbon-free. Japanese scientists were the first in the world to couple an operational HTGR nuclear reactor to a thermochemical-cycle hydrogen production plant. A test reactor was actually operational as early as 2004, and ran successfully for 50 days at full power in 2010 (the helium coolant temperature was 1,742 degrees).

After the Fukushima disaster, however, the experimental reactor was put on hold. But ten years later, after passing all safety standards, the reactor was restarted on July 30, 2021, and has been operating at full power ever since. In February 2022, Mitsubishi Heavy Industries was commissioned to build Japan’s biggest-ever hydrogen production plant using the new system known as High Temperature Engineering Test Reactor (HTTR).

This new HTTR plant will be the first time large quantities of hydrogen have been produced in a constant, reliable, and economically feasible way without the risk of future meltdowns, thanks to multiple safety features. These safety features include the use of tri-structure Isotropic fuel, which is made of tiny ceramic kernels with 6 percent uranium oxide, and covered with four layers of highly-resistant ceramics. This encapsulation traps radioactive waste inside - and makes it nearly impossible for the waste to be released into the atmosphere in case of an accident.

Nuclear waste barrell storage

But What About Radioactive Waste?

While there are those who see this technology as a game-changer in the quest for carbon neutrality, there are still questions about radioactive material, which still must be disposed of after the fuel is used. Although the fuel is much more safely contained in ceramics, HTTR facilities will still generate nuclear waste, as much as the older technologies did. There are currently over 250,000 tons of nuclear waste housed in underground tunnels all over the world - and much of that waste will remain radioactive for thousands of years.

How will we manage the radioactive waste produced by this new form of nuclear energy for the next couple of thousand years? It’s a topic too complex to address in this article, but more information may be found here on what we’re doing with our radioactive nuclear waste. Complex problems require complex solutions. We remain hopeful that more breakthrough innovations and technology will surface over time and help us move further toward a truly greener world.

A young couple admiring the forest and trees next to their RAV4 Hybrid

Join the sustainable transportation evolution.

Subscribe to receive the latest GreenCars news, products, and updates

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.