As we witness global energy demands becoming progressively complex and decentralized, decarbonization stands as one of the biggest challenges of the current generation. Addressing the issues surrounding the climate and energy crisis requires a multifaceted approach and one increasingly attractive power source to fuel the green energy transition is hydrogen.

Hydrogen can not only be used for storing excess energy of fluctuating renewable sources such as wind or solar—and later be used to generate climate-neutral electricity and heat via a fuel cell—it can also be used for production of e-fuels or as a fuel in hydrogen engines. While hydrogen is not a magical cure-all and may not be the optimal solution for every situation, it is already essential for many core industries, such as in treating metals, producing fertilizer, and processing foods. Furthermore, demand for hydrogen is expected to rise significantly in the coming years, as it will play a large part in decarbonizing heavy industry and chemical production, and set a basis for derivative fuels in the mobility sector, among other uses.

Green Hydrogen Opportunities

Due to factors such as cost, much of the hydrogen used by industries worldwide today is still sourced from fossil fuels, resulting in carbon emissions. Therefore, a transition to other forms of hydrogen production that create no CO 2 emissions, such as via electrolysis from renewable sources, is needed. But how can we responsibly and affordably produce the huge quantities of hydrogen that will be in demand? One answer: by using a modular approach and offering scalable production options that will help make affordable production of green hydrogen more accessible on a per case basis.

In the depths of the ongoing discussion around securing less-expensive ways to produce green hydrogen, one thing is certain—a more sustainable energy landscape will be more complex and diverse than we are used to, with no one-size-fits-all approach. With more than a century of experience in engineering and technology across various industries, Rolls-Royce understands that a diverse portfolio of renewable technologies is essential to achieve a successful energy transition.

Rolls-Royce sees an important role for hydrogen in helping to lower transport emissions, as well as for energy storage, heating, and even powering smaller aircraft using fuel cells. This is why the company has entered the market for scalable solutions for green hydrogen production, beginning to bridge the gap for sustainable transition by developing a solution to produce hydrogen cheaply and on a large scale using green electricity. In 2022, the company acquired a majority stake in electrolysis stack specialist Hoeller Electrolyzer, whose highly efficient polymer electrolyte membrane (PEM) stack technology forms the basis of a new range of mtu electrolyzer products from the Rolls-Royce Power Systems division.

Electrolyzer Technology

In hydrogen electrolysis, water is broken down into its components—hydrogen and oxygen—by an electrochemical reaction, producing hydrogen at the negative pole and oxygen at the positive pole. The electrochemical reaction takes place in a cell between plate-shaped electrodes separated by membranes. Hundreds of cells located one above the other and pressed together form a “stack,” arranged in such a way that they produce the required amount of hydrogen as economically and effectively as possible.

Ensuring no CO2 is produced during hydrogen production, solar parks, wind turbines, and hydropower plants are used to supply the electrolyzers with electricity. The collected hydrogen from the electrolyzers can be used in fuel cells or to power hydrogen engines, feeding electricity into a power grid or used to power vehicles, ships, or in industrial manufacturing applications.

The aforementioned mtu electrolyzer product range will allow customers to store renewably produced energy in the form of hydrogen for use or for further processing and will serve as key components in larger-scale renewable cross-section energy systems. Solutions such as these can offer a modular design that are scalable in power range to provide a fully autonomous, high-power, high-efficiency solution for low-cost production of hydrogen. The first mtu electrolyzer using a Hoeller stack is set to go into operation this year, showing the part an electrolyzer can play in the overall architecture of a microgrid system.

The introduction of green hydrogen is not without its challenges, however. As part of an individual energy system, hydrogen increases the number of technologies required for operation, raising the complexity of operating strategies and creating new challenges in automation and controls. As industry transitions from today’s hybrid solutions that feature hydrogen as a component to tomorrow’s multiple hydrogen-based technology solutions, operation strategies will need to be adapted and respective intelligent asset controls will need to be integrated.

Offering one way to address this, Rolls-Royce is introducing a new system called mtu EnergetIQ, a smart automation platform that continuously recalculates the best operating strategy of complex energy systems while taking forecasts of renewables, prediction of energy demand, and hydrogen and cost into account. The platform can be used to calculate the ideal mix in terms of power generation, storage, and requirements. Capabilities like that of EnergetIQ will be increasingly important as manufacturers begin to reconceptualize their power supply systems, as the future of energy technology lies in increasing diversity, complexity, and integration.

Armin Fürderer is head of net-zero solutions with Rolls-Royce Power Systems.