Some power industry insiders believe hydrogen offers a solution to large-scale energy storage problems. The concept generally revolves around utilizing electricity generated by renewables when supply is high and demand is low. This could be around mid-day when solar power production is peaking but the need for power is relatively light. Rather than curtailing output, the excess power could be used to produce hydrogen through electrolysis, for example, with the hydrogen stored for later use. Then, when demand picks up and renewable supplies tail off around sunset, the hydrogen could be used to fuel a combustion turbine, thus supplying renewable energy.
Hydrogen Power Projects
There are several original equipment manufacturers (OEMs) working on hydrogen-related technology including Mitsubishi Hitachi Power Systems (MHPS). The company announced in May 2019 that it was partnering with Magnum Development, the owner of a large and geographically rare underground salt dome in Utah, on a project that could store up to 1 GW of renewable energy year-round and provide it to power markets in the western U.S. The $1 billion Advanced Clean Energy Storage project in Millard, Utah, is viewed as a potential game-changer for the industry.
“We’ve made a lot of progress on the project,” Paul Browning, CEO of MHPS Americas, told me during an exclusive interview in November. “As you get to higher and higher renewables penetration on a grid, like California, for example, you need storage, because as you start to drop natural gas out, you need something that’s going to be there when the wind’s not blowing and the sun’s not shining, which is what natural gas’s job is in California right now,” he explained.
“What you need is storage. Right now, what’s getting done is a lot of lithium-ion storage, and that’s because what the California grid needs right now is short-duration storage of a few hours,” Browning said. “But as you continue to decarbonize, and you continue to drop more natural gas off of your grid, you start to need longer-duration storage. You know, you need the storage that’s going to be able to store electricity for days, or weeks, or months, or years. And when you get into those kinds of longer-duration storage, lithium-ion just gets prohibitively expensive. And so, that’s where hydrogen comes in.”
But storing large amounts of hydrogen isn’t the only challenge, you also need to be able to burn it in a gas turbine while meeting strict emissions requirements. That’s why MHPS is also working on a Carbon-Free Gas Power project in the Netherlands. That endeavor aims to convert one of three units at the 1.32-GW Magnum combined cycle power plant to run on 100% hydrogen by 2025.
Browning offered a brief explanation of the modifications necessary to accommodate hydrogen as a fuel. “A gas turbine has three main sections: the compressor section, the combustor, and the turbine section,” he said. “The compressor section and the turbine section are unchanged. What changes is the combustion section—where we combust the fuel.” Browning said hydrogen is a much different molecule than methane, so the combustion physics are very different.
“We need a different combustion technology to burn hydrogen in a dry low-NOx kind of way. So, that’s what we’re in the process of developing right now. Our existing technology can burn 30% hydrogen. The new stuff is going to be able to burn 100% hydrogen,” he said.
Fundamental Changes and Unique Hydrogen Uses
Nakul Prasad, gas turbine portfolio manager with Siemens Energy, said when he first joined the company and started looking into hydrogen, the technology had been researched on and off for years. Naysayers suggested to him that exploring hydrogen options would be just another fad, essentially a “flavor of the month.” However, Prasad has not been so quick to dismiss the possibilities.
“This time it’s fundamentally different because you have renewables driven by carbon reduction,” Prasad told me when we visited during an event in New Orleans. “Hydrogen is becoming a centerpiece now, because it’s a feedstock to many different industries, and as a storage medium—getting surplus renewable energies—helping the industry decarbonize. And so, hydrogen takes up a new role now. I think that’s why momentum is building up. It’s not like in the past, something segregated, it’s really something integrated now.”
Not only is Siemens working to increase the percentage of hydrogen its gas turbines can burn, but also the company is developing large-scale technology for the production of hydrogen. In November, Siemens announced that it would supply a 2.2-MW proton exchange membrane (PEM) electrolysis plant to a German steel manufacturer. Hydrogen has long played a role in steelmaking by enhancing the quality of annealing processes. The necessary electrical power for that system will come from a 30-MW seven-turbine wind installation.
Genoa, Italy-based Ansaldo Energia is another OEM focused on hydrogen. In October, the company said it had partnered with the Stavanger, Norway-headquartered international energy company Equinor to validate a 100% hydrogen gas turbine combustor. Ansaldo said that equipping its GT26 and GT36 gas turbines with a unique sequential combustion technology has “allowed the utilization of the full range of hydrogen in a low-NOx premix system.”
Furthermore, Ansaldo said it offers extensively tested and commercially proven combustion system retrofit solutions for the installed base of F-class gas turbines, including those manufactured by GE, Siemens-Westinghouse, and MHPS. While the upgrades don’t allow unlimited hydrogen combustion, they are said to provide an “impressive load range” and “unmatched hydrogen volume percentages.” Ansaldo suggested owners can “Future-Proof” assets by having hydrogen fuel flexibility. ■
—Aaron Larson is POWER’s executive editor.