As a Professor of Mechanical & Aerospace and Civil & Environmental Engineering at the University of California Irvine, Jack Brouwer is keenly aware of the challenge of informing the public and policymakers about the crucial role of hydrogen in achieving our zero-emissions goals. In his role as the Director of the Advanced Power Energy program and the National Fuel Cell Research Center, he spearheaded a groundbreaking power-to-gas-to-power initiative showing that renewable hydrogen can be safely injected into existing natural gas pipelines to ensure the ubiquitous delivery of hydrogen as a zero-emissions renewable fuel for a wide range of applications. We sat down with Professor Brouwer for an eye-opening lesson about the limitless potential of hydrogen and fuel cells as a complement to battery electric.
When you start looking at the need for us to achieve zero emissions, you cannot do it with batteries and solar and wind alone. We need something else that enables long-distance, rapid fueling and heavy payload.
I was interested in energy and the environment even as a kid growing up and driving vehicles on a farm near San Diego. Vehicles really sparked my interest in energy in general. In grad school, I wanted to do something to reduce emissions and improve the efficiency of energy conversion. I realized you could never get to zero emissions with combustion, so I started looking for alternatives. Battery and solar came immediately to mind, but I wondered how they could ever power long-distance travel. It’s not really possible. Fortunately, the concept of a fuel cell, with separate hydrogen storage and a zero-emissions energy conversion device, can enable this long-distance travel, and with totally zero emissions. When you start looking at the need for us to achieve zero emissions, you cannot do it with batteries and solar and wind alone. We need those and something else that enables long-distance, rapid fueling and heavy payload.
In the state of California where we have a progressive and legal requirement to achieve zero emissions by 2045, agencies are beginning to take a close interest in hydrogen.
The United States has been slow to adopt a formal policy for climate change. As a matter of fact, it never joined the Paris Climate Accord. And yet, corporations and agencies have realized for quite a while that we must eventually do something to reduce our impact on the climate and air pollution. If we focus on the health and air quality impacts, I think we have a chance to convince most Americans that we should invest in these clean technologies. There have been some huge advancements lately, such as the US Department of Energy’s Hydrogen at Scale initiative. This project is evaluating and advancing hydrogen in a number of applications, notably to support the 100% renewable grid, as well as for ammonia, cement and steel production. In addition,in the state of California where we have a progressive and legal requirement to achieve zero emissions by 2045, agencies are beginning to take a close interest in hydrogen. They know that for heavy-duty transport and for decarbonizing shipping and aviation, we need something more than just batteries and solar. Even though we’ve taken a haphazard approach, companies and certain states have done a very good job and are at least considering hydrogen as part of the solution to get to zero emissions.
Let me emphasize that hydrogen is still not considered by most jurisdictions throughout the United States. That is primarily because they have been preoccupied with getting from 10% renewable to 50% renewable. If you only care about getting to 50% renewable, then hydrogen isn’t required, so they haven’t even thought about it as part of the solution. I don’t want to be too negative, but the fact is that when you just think about a 50% emissions reduction, you don’t need hydrogen. You can do a lot with solar and batteries. But if you want to get to zero emissions, you need solutions that only a zero-emissions renewable fuel can provide. And I think the best one is hydrogen.
We’ve been exploring at UC Irvine how to transform the current fossil natural gas infrastructure to become the renewable hydrogen infrastructure of the future
Most of the infrastructure associated with moving hydrogen around in society doesn’t exist at all. This is part of why batteries are more popular today. We already have electric infrastructure to charge battery electric vehicles. It’s everywhere. Most people can charge their vehicles at their homes. But with hydrogen, because it’s difficult to transport and we haven’t done it previously, we have almost none of the infrastructure we need, which can include liquefaction and compression plants, as well as trucks for liquid and gaseous delivery. Ultimately, we will need a much more prevalent fuel delivery system than just truck delivery for this zero-emissions fuel. That’s when you start to think about a pipeline network that would also deliver this to individual industries, fueling stations and to homes for people to use in barbecues, stoves and other appliances. That is a difficult proposition, because we invested hundreds of years in our electric grid and natural gas grid, with zero investment so far in a network of hydrogen. Yet this is precisely what is required in the long run to expand the use of hydrogen. It will take some time to do that. One of the ideas we’ve been exploring at UC Irvine is how to transform the current fossil natural gas infrastructure to become the renewable hydrogen infrastructure of the future. I think that’s going to be one of the least costly means by which we can make hydrogen ubiquitous and enable a zero-emissions future.
Our project was the first in the US to demonstrate the idea of taking renewable electricity and storing it in the form of hydrogen, and also injecting it into the natural gas system to partially decarbonize that gas.
We operated from 2015-2019 a power-to-gas-to-power demonstration plant, where we showed that we can safely inject up to 4% hydrogen into natural gas pipelines without any modification, safety hazards or increase in emissions. Our project was the first in the US to demonstrate the idea of taking renewable electricity and storing it in the form of hydrogen, and also injecting it into the natural gas system to partially decarbonize that gas, while producing renewable electricity from it using an electricity producing asset. This is one of the least costly means by which we can install more and more solar and use that solar more continuously. If we alternatively tried to store all that solar energy in batteries, it would be much more expensive than storing it as renewable hydrogen, repurposing the natural gas system and using existing power assets to produce it. I think it was important for us to not only publish papers on the topic, but to actually demonstrate it with physical infrastructure on our campus, so that policymakers could see that it’s essential to include hydrogen as part of our zero-emission future.
The cost of a battery energy storage system is linearly related to its energy storage amount. Hydrogen is different. You can design the power to correspond to the electrolyzer and fuel cell size.
When you have a small amount of energy to store, batteries are the preferred solution. Hydrogen becomes the preferred solution when you need either a large amount of energy or to store the energy for a long duration. Why? Because batteries have only a certain amount of energy they can store. If you need more energy, you need more batteries, the cost of a battery energy storage system is linearly related to its energy storage amount. You have to buy more batteries if you need more kilowatt hours. Hydrogen is different. You can design the power to correspond to the electrolyzer and fuel cell size, and then store the hydrogen separately in a tank. If you need more energy, you just make the tank bigger, which doesn’t cost much more. That’s why salt caverns, which are a massive energy storage solution, end up being a much cheaper zero-emissions solution than buying batteries to store the same amount of energy.
More than 3,000 salt caverns in Texas can be used for massive energy storage that is much cheaper than the equivalent battery energy storage could ever achieve.
In 2010, we started doing modeling work to consider a salt cavern for hydrogen energy storage. That is now a reality today: two salt caverns in Texas are currently being used to store and deliver hydrogen, mostly to refineries. But there are more than 3,000 salt caverns in Texas, and I am sure they can be used for massive energy storage that is much cheaper than the equivalent battery energy storage could ever achieve. I think we can transform underground storage facilities and gas pipeline networks for hydrogen, because it’s already been proven by several companies in Texas.
The roundtrip efficiency of the hydrogen energy storage system will become competitive with investments in fuel cells and electrolyzers.
Current electrolyzer and fuel cell technology offers a roundtrip energy efficiency of 50-60%. But here at UC Irvine, we’re working on solid oxide electrolysis and solid oxide fuel cell technology, which can be made into a reversible solid oxide system. This kind of system can achieve a roundtrip efficiency above 80%. If we achieve this level, then we are competing directly with the efficiency of battery electric storage solutions. Even though today the roundtrip efficiency of the hydrogen energy storage system is lower than that of battery energy storage systems, it will be improved over time and I think it will become competitive with investments in solid oxide fuel cells and electrolyzers.
We are working on two projects involving power-to-gas-to-power at a larger scale, while demonstrating the concept with the utility infrastructure. Since our campus at UC Irvine had no standard for injecting hydrogen into the utility infrastructure, we were able to run this demonstration much earlier than they did. Now we are collaborating with Southern California Gas (SCG) and Pacific Gas & Electric (PG&E) to establish larger projects to inject hydrogen into their infrastructure and develop a standard so this can be done on a widespread basis. For example, we are looking to produce renewable hydrogen from University of California owned and operated solar farms in the central valley. These solar farms are permanently curtailed because of grid constraints, and we want to introduce renewable hydrogen at those sites and inject it into either PG&E or SCG resources. In addition, we are working with Microsoft to consider renewable power for data centers that includes a hydrogen energy storage solution. If we can demonstrate this same concept not only on our campus but also across utility service territories and using utility infrastructure, then I think it will spur along policies for the transformation of our natural gas system into a renewable hydrogen system.
You cannot make ships zero emissions with batteries, but you can with hydrogen
The main challenge for adopting hydrogen is, as I said earlier, the fact that we essentially have zero infrastructure today to enable its storage and transport. So how do we get hydrogen to spread? I think we need to see the first jurisdiction adopt hydrogen as a solution in a difficult to decarbonize sector, such as shipping. If we aim to decarbonize only the ships that go in and out of the LA-Long Beach Port, our investments in electrolyzers, pipelines, solar and wind resources required to produce renewable hydrogen, as well as a corresponding transformation of these ships, would make hydrogen cheaper than the diesel fuels currently used to send those ships across the Pacific Ocean. You cannot make ships zero emissions with batteries, but you can with hydrogen. If we make a big enough investment in hydrogen, I think it will displace fossil fuels, not because we are running out or because of policy, but because the infrastructure and production cost will be cheaper than diesel for example.
Because of the benefits it offers in terms of separate scaling of power and energy, hydrogen always figures into making the electric grid 100% zero emissions.
In our paper,“Hydrogen is Essential for Sustainability”, there are 11 different reasons why hydrogen is important for us to include in our zero emissions policy goals. In the transportation sectors, anything that needs rapid fueling, long range or heavy payload will need a solution like hydrogen to make it zero emissions. Many industries will also need hydrogen to become sustainable, such as steel and fertilizer production. When the electric grid gets close to 100% renewables, in every analysis that has ever been done anywhere around the world, you realize that you need some seasonal storage, meaning long duration and massive amounts of storage. Because of the benefits it offers in terms of separate scaling of power and energy, hydrogen always figures into making the electric grid 100% zero emissions.
I’ve yet to find anything that can do everything that hydrogen can do. I’m sure it’s going to be the tool we need to enable zero emissions. Without hydrogen, I don’t think we can achieve this goal. Another thing that keeps me passionate are my graduate students. They are making huge contributions in the field by cementing hydrogen and fuel cell technology as part of the solution for getting to a more sustainable society.
Professor Jack Brouwer, Director, National Fuel Cell Research Center (NFCRC) at UC Irvine explores and presents the different sources of renewable energy that can help us build a sustainable world.