How fuel cells can power the future: an interview with Chae Geun-seok

Just as much attention is given to renewable energy as a promising sustainable solution, fuel cells deserve more recognition. Chae Geun-seok is a 30-year veteran researcher of fuel cells and currently a CEO of Second To None Hydrogen Energy (STH), a company specializing in fuel-cell catalysts. His expertise in fuel cells offered a valuable perspective on fuel cell's synergy with renewable energy and how scientific advancements alone cannot tackle net-zero.  

Firstly, what kind of fuel cell technology are you researching?

Since my graduate studies, I've been working on carbon supports for fuel cells. That's because platinum is the primary catalyst used in hydrogen fuel cells. We use a platinum catalyst, but instead of using pure platinum, we load it onto carbon. For example, we might use a 50% PTC mixture. A 50% PTC mixture means that for every 1g, 50% is 0.5g of carbon and 50% is 0.5g of platinum. This is called a 50% PTC catalyst. If we have a 30% PTC, it's the opposite: 0.7g is carbon and 0.3g is 100g. So, while platinum is crucial in the total catalyst, the carbon support is also extremely important.

And now, my work involves developing carbon catalysts. While developing these catalysts, I also research how to effectively combine the carbon support with platinum. This includes determining whether to uniformly deposit the platinum onto the support. That's the main focus of my research.

So why is this catalyst important? In a fuel cell, the catalyst enables reactions like the oxidation of oxygen, the oxidation of hydrogen, or the reduction of oxygen. These reactions create electrons and consume electrons to produce water while generating electricity. Therefore, the oxidation of oxygen and hydrogen must occur efficiently, and conversely, the reduction of oxygen must also proceed smoothly. Only then can water be produced rapidly and electricity generated. Yes, the place where all that happens is right here on the platinum.

Next, the carbon support plays a big role in lifespan, whether it lasts long or wears out slowly. Since the carbon mustn't oxidize, carbon starts oxidizing at 0.127 volts. If oxidation occurs, the carbon disappears as CO2 gas, so the platinum there will go somewhere. It might stick to the side or leach out and disappear. Then the active sites decrease, so the activity and performance drop, shortening the lifespan.

Therefore, our research focuses on creating highly durable, crystalline graphitized carbon supports to prevent this lifespan reduction. Specifically, we study how to effectively deposit platinum onto these graphitized supports, applying this research to both HEM and DMMP applications.

So, compared to existing fuel power generation methods, what is the biggest advantage of the fuel cell you just explained?

From a fuel cell perspective, there are two main types: the control-type and heat-retaining type. The heat-retaining type is called SOFC, which stands for Solid Oxide Fuel Cell. Since these operate at high temperatures, they don't require large-scale heat sinks. Therefore, that isn't our target market. Our focus is on low-temperature fuel cells using hydrogen, or other raw material fuel cells. 

So, as you just mentioned, if we ask what the advantages are, first, compared to existing commercial products sold by global companies, we increased the crystallinity of the carbon. Increased carbon crystallinity means improved lifespan, giving the advantage of longer-lasting use.

Existing catalysts have the problem of carbon oxidation occurring easily, shortening their lifespan. What we're researching now prevents carbon oxidation, so the lifespan naturally increases. One advantage is the extended lifespan. Additionally, because the platinum is well-bonded, performance is also excellent. So, while the lifespan increases, performance is also maintained. For example, something that typically lasts 5 years can last 10 years, offering this advantage.

What do you see as the most crucial way this fuel cell technology can contribute to achieving carbon neutrality?

Well, fuel cells are generators that produce electricity. So, compared to secondary batteries, which are energy storage devices, they are charged using electricity typically produced from fossil fuels, and once a certain capacity is charged, they discharge that stored energy for use.

In contrast, a fuel cell is an actual generator that supplies hydrogen and oxygen from the air to produce electricity. Therefore, the hydrogen used in this fuel cell is defined as various types of hydrogen we hear about these days, like green hydrogen, blue hydrogen, pink hydrogen, and so on. So, using oxygen and hydrogen as fuel means it doesn't emit CO2 like fossil fuels do.

A fuel cell produces electricity by decomposing water and using hydrogen, so it's carbon-free, and can have a huge impact on achieving carbon neutrality. But the most important thing is that while there are various types of hydrogen produced using existing fossil fuels, like gray hydrogen, what we're talking about now is using hydrogen like pink hydrogen or green hydrogen to power fuel cells for electricity generation. This creates a completely carbon-free energy source, making it the most suitable energy device for achieving carbon neutrality, which is what you're working on right now. 

How can fuel cells be used with renewable energy?

When fuel cells operate independently with renewable energy, it means using renewable energy to produce hydrogen. Electricity is generated from sources like solar or wind power, but the problem is that solar and wind power have limited generation capacity. For example, solar power doesn't generate electricity on cloudy days, and wind power doesn't generate electricity when there's no wind.

However, wind and solar energy still generate electricity for about 3.5 to 4 hours a day. So, if we use that electricity to produce hydrogen, and then use that hydrogen to power fuel cells, we're creating hydrogen entirely from renewable energy and using fuel cells to generate electricity. Only with this kind of system can we achieve true carbon neutrality, as I mentioned earlier.

So synergy with renewable energy is essential, right?

Exactly. That's why it's so much more significant. The synergy means, as you just mentioned, using electricity generated from wind or solar power to electrolyze water and produce hydrogen. Then, using that produced hydrogen to power an electric fuel cell, the electricity generated becomes a truly carbon-neutral, carbon-free energy source.

Besides carbon emissions, how do fuel cells tackle other environmental concerns, such as pollutants?

In the case of fuel cells, as I just mentioned, if you use green hydrogen produced through water electrolysis, absolutely no pollutants are emitted. Why? Because when you split water, you only get hydrogen and oxygen. You feed that hydrogen into the fuel cell to generate electricity, so the only byproducts are heat and water, which are not wasted. The heat byproduct can be used as heating, for example. 

What I'm talking about now is when using green hydrogen. But if you use grey hydrogen, for instance, the hydrogen itself might have some impurities, so that could lead to some greenhouse gas emissions. However, compared to the amount emitted by internal combustion engines, it's significantly lower, whether it's one-tenth or one-twentieth, so it shouldn't be a major problem.

How significant is the role fuel cells can play in Korea's current power structure, and how much further can they grow?

Currently, nuclear power likely accounts for over 30% of electricity generation in our country, probably reaching 40-50%. Nuclear power comes first, followed by fossil fuel-based coal power as the second largest source. There are also other sources like hydroelectric power, but renewable energy's share in our country is significantly lower compared to advanced nations. It's probably around 7% to 10% or less. So, the installed capacity of fuel cell power generation in Korea is currently a few gigawatts, about 1.1 gigawatts or 1 gigawatt. Considering Korea's total power generation capacity, 1 gigawatt represents a very small percentage.

Therefore, we must gradually improve the efficiency of fuel cell power generation and increase its operational time. For fuel cell power generation to replace fossil fuels, it is crucial that the hydrogen production via electrolysis mentioned earlier produces sufficient hydrogen to power the fuel cells. Supplying this electricity to ordinary citizens would then be highly cost-effective.

Furthermore, the greatest advantage of fuel cells is that they are distributed power sources installed locally. For example, with coal-fired power plants, once installed at a site, transmission towers must be erected to bring the power lines there. Just erecting one transmission tower costs over 100 million won. Fuel cells, being locally installed, minimize the need for transmission and distribution lines. So, if it's in Jamsil, you can just install one there and connect it to the existing KEPCO grid nearby, making it easy to use. These are significant advantages.

To further expand these benefits, a lot of research seems to be underway. What do you think are the most challenging aspects of that research?

From my perspective, the systems and technologies for commercial fuel cell power generation projects are already fully developed and commercialized. The technology itself seems complete for commercialization. The real problem, as mentioned earlier, is hydrogen. If you install fuel cells next to people's homes, hydrogen will be present, and many residents perceive hydrogen as a bomb, so complaints will arise, and it won't be allowed. Our citizens need to gain some understanding of hydrogen's safety and knowledge about it to feel assured that it's safe. 

Take fuel cell vehicles like the Nexo—there are plenty of them on the road now. But in Seoul, there are almost no charging stations in the city center. They're all on the outskirts. The only one in the city center might be the one near the National Assembly building. Even trying to put a single charging station like that in the city center triggers complaints, making it impossible to install. Resolving these issues seems to be the biggest challenge. That's why power plants are currently being built in industrial complexes or other areas where there's little potential for complaints. 

When these plants move into cities, combined heat and power generation becomes possible. Why? Because if a fuel cell plant is rated at 100 megawatts, it produces 100 megawatts of heat, and if we use that to generate hot water, we can send it directly to homes and apartments. Instead of each apartment having a gas boiler, they could use this heat pipeline system. This offers a huge advantage. 

However, the issue isn't that the technology isn't developed yet. From my perspective, the technology is almost fully developed. Why? Because about 1 gigawatt is already installed and running now. Technically, there's no problem. But for this fuel cell power generation to become commercialized, the stability of hydrogen supply must be ensured to increase resident acceptability. We need a system where we safely produce hydrogen using electrolysis, and that same electrolysis is used directly to power the fuel cells. Only then can we achieve eco-friendliness, become carbon-free, and complete carbon neutrality.

The public complaints you mentioned seem to be something other interviewees also bring up. They said public opposition is a big issue regarding renewable energy installations and such. My final question connects to this: you mentioned fuel cells could create good synergy with renewables. What kind of policy support would be needed to maximize that synergy?

Now, our country also has a mandatory target to increase the proportion of renewable energy, and to achieve that NDC, the most crucial element is hydrogen. Fuel cells are the best device for utilizing hydrogen. So, to achieve the hydrogen NDC, we need to produce this hydrogen efficiently and stably. The biggest problem with this simply produced hydrogen is transportation, and storing it is tough because it's the lightest element on Earth.

So instead of long-term storage, if the electrolysis is right there, and if there's a hydrogen production site, we just need to put the fuel cell equipment right next to it to generate electricity immediately and supply it like this.The government shouldn't just talk about it, but rather they need to actually provide substantial support for such policies and initiatives. Building just one fuel cell power plant costs a tremendous amount of money, and that's why the government must provide substantial policy support for these areas. Only then can citizens easily undertake such power generation projects.