6.10.24
Jan Overney
Illustration © Éric Buche
Green hydrogen could transform our energy system and solve many supply and emissions challenges. Whether this happens will depend on how economically it can be produced and attractive it will be to consumers.
Among the promising technologies for powering a net-zero future, hydrogen is a bit of an outlier. While solar panels, wind turbines, and hydropower plants all harness energy provided by nature and transform it into electricity, hydrogen doesn’t fit into that mold. Andreas Züttel, head of EPFL’s Laboratory of Materials for Renewable Energy, explains why: “Hydrogen is not an energy source, it’s an energy carrier.”
Already today, hydrogen is at the core of our energy system. Packing more energy per unit mass than any other substance known to man, hydrogen serves as the primary energy carrier in our fossil fuels. Hydrogen’s free combustion with oxygen has blasted rockets into space. And thanks to our ability to control its combustion in fuel cells, it now powers a steadily growing fleet of vehicles on our roads.
According to Züttel, the problem with the hydrogen used today is that most of it, some 95%, is dirty. Where we rely on it, as in hydrocracking in oil refineries, producing synthetic fertilizers, and in the chemical industry, we source it from fossil fuels — which means a hefty carbon footprint.
A challenging shift to green and clean
Surprisingly, this very same substance is being hailed as a vital contributor to a net-zero-emissions energy system. The Swiss Federal Office of Energy (SFOE) sees clean, green hydrogen playing an important role in Switzerland’s clean energy mix by 2050, starting from close to zero today.
Achieving this will require a major hydrogen clean-up. To shift from dirty hydrogen to clean hydrogen will require addressing hydrogen’s many inherent challenges. Chemically, its lack of a liquid phase at room temperature makes it difficult to store. It is notoriously explosive, making it delicate to handle. And its inability to be odorized complicates leak detection.
In terms of energy efficiency, hydrogen lags behind other energy sources, requiring vast amounts of energy – 66 kilowatt hours per kilogram – to be produced. And the same is true from an economic perspective, with the cost per kWh of energy carried by hydrogen around two to three times higher than the market price for electricity.
Given all these drawbacks, why is there so much hope for hydrogen? Because, under the right conditions, this renewable energy carrier’s properties could address challenges that will arise as we move towards a cleaner and greener energy mix.
The Swiss Army Knife of energy carriers
Research into hydrogen as an energy carrier surged in the 1990s, says Züttel. “When I entered the field 32 years ago, we thought hydrogen would replace all fossil fuels. In those days, we weren’t yet hoping to combat global warming, we were trying to address the fear that fossil fuels would soon run out.” As new fossil fuel deposits were discovered and increased production drove down their cost, the hydrogen hype cooled down.
But now, the pendulum has swung right back. Hydrogen is once again in the spotlight, says Züttel. This time it’s for its potential to help curb global CO₂ emissions. While burning carbon produces heat-trapping CO₂, burning hydrogen produces nothing but water. If renewable electricity is used to produce hydrogen, for example through the electrolysis of water, the resulting hydrogen becomes an effective way to store renewable energy.
“Hydrogen is the key element on the path from renewable electricity to chemical energy carriers such as methane, methanol, synthetic oil or ammonia,” explains Züttel. “While these can be produced using carbon from captured atmospheric CO₂ or from biomass, the hydrogen carries the renewable energy.”
This makes hydrogen a valuable energy carrier for a variety of applications. Pure hydrogen can be used to generate electricity to meet peaks in demand, and it can power cars, busses, and heavy vehicles. If we managed to solve the storage, distribution and handling puzzle, then we could start using it as a carbon-neutral fuel for shipping and aviation.
Combined with carbon extracted from the atmosphere, biomass or industrial emissions, it could be further transformed into methane, synthetic oil, ammonia, methanol or other net-zero-emissions fuels. This would, again, come at the cost of overall energy efficiency. But in a world awash with renewable electricity, the increased volumetric energy density and safety of handling that these synthetic fuels provide help cut the carbon footprint of applications that are difficult to electrify.
Accelerating market adoption
Fortunately, says Züttel, there have been several breakthroughs on the path to market adoption of green hydrogen in transportation and electricity production, the two sectors responsible for more than half of the world’s greenhouse gas emissions. They begin upstream of hydrogen production, where renewable electricity has already achieved price parity with standard electricity, decades earlier than initially predicted by the International Energy Agency, bringing down the cost of clean hydrogen with it.
Market forces have been a key driver in road vehicle applications, accelerating the development of fuel cells and safe high-pressure hydrogen storage cylinders. Despite these advances in technology, adoption of hydrogen-powered vehicles has been frustratingly slow. In fact, the main obstacle has been the lack of roadside infrastructure. Switzerland currently has eight hydrogen refueling stations, says Züttel. “People won’t buy a hydrogen car if they can’t fuel it. And who wants to run a fueling station if no one wants to buy the hydrogen? That’s the reason why Toyota is not selling their fuel cell electric vehicles here.”
As the share of intermittent renewable electricity carried by the power grid increases, power plants will likely become increasingly reliant on stored hydrogen to match the supply and demand for power. “If you have a lot of volatile electricity, say from solar or wind power, you can produce hydrogen and store it underground, for example. Then, you can use that in the wintertime to produce electricity with a high efficiency in combined cycle power plants that have a hydrogen fired turbine and a steam turbine,” he says.
“For this to work, the whole market — and our expectations — will have to adapt. We are used to buying electricity at an almost constant price. To make storage attractive, the price of electricity during the night would have to be more expensive than during the day. And in the winter, we would have to be prepared to pay more than in summer months. But the more attractive it becomes to store electricity using hydrogen, the more such storages will be installed,” he says.
To stimulate market growth on both the supply and the demand side, the industry has come up with a colorful solution — at least in name. Hydrogen is now being marketed on a color spectrum ranging from black to green based on carbon footprint. When developing new applications, hydrogen users can now make a conscious choice whether to prioritize carbon footprint or cost. This strategy will eventually nudge consumers up the spectrum towards greener hydrogen as it becomes more and more affordable.
However, as Züttel emphasizes, this only makes sense as a temporary strategy, in place long enough to build up demand for hydrogen and the infrastructure to distribute it. “Once we start using a lot of hydrogen, it will have to be renewable hydrogen only. Anything else would not really make sense.”
See the full article here .
Comments are invited and will be appreciated, especially if the reader finds any errors which I can correct.
five-ways-keep-your-child-safe-school-shootings
Please help promote STEM in your local schools.
The Swiss Federal Institute of Technology in Lausanne [EPFL-École Polytechnique Fédérale de Lausanne] (CH) is a research institute and university in Lausanne, Switzerland, that specializes in natural sciences and engineering. It is one of the two Swiss Federal Institutes of Technology, and it has three main missions: education, research and technology transfer.
The QS World University Rankings ranks EPFL(CH) very high, whereas Times Higher Education World University Rankings ranks EPFL(CH) as one of the world’s best schools for Engineering and Technology.
EPFL(CH) is located in the French-speaking part of Switzerland; the sister institution in the German-speaking part of Switzerland is The Swiss Federal Institute of Technology ETH Zürich [Eidgenössische Technische Hochschule Zürich] (CH). Associated with several specialized research institutes, the two universities form The Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles Polytechniques Fédérales] (CH) which is directly dependent on the Federal Department of Economic Affairs, Education and Research. In connection with research and teaching activities, EPFL(CH) operates a nuclear reactor CROCUS; a Tokamak Fusion reactor; a Blue Gene/Q Supercomputer; and P3 bio-hazard facilities.
ETH Zürich, EPFL (Swiss Federal Institute of Technology in Lausanne) [École Polytechnique Fédérale de Lausanne](CH), and four associated research institutes form The Domain of the Swiss Federal Institutes of Technology (ETH Domain) [ETH-Bereich; Domaine des Écoles polytechniques fédérales] (CH) with the aim of collaborating on scientific projects.
The roots of modern-day EPFL(CH) can be traced back to the foundation of a private school under the name École Spéciale de Lausanne in 1853 at the initiative of Lois Rivier, a graduate of the École Centrale Paris (FR) and John Gay the then professor and rector of the Académie de Lausanne. At its inception it had only 11 students and the offices were located at Rue du Valentin in Lausanne. In 1869, it became the technical department of the public Académie de Lausanne. When the Académie was reorganized and acquired the status of a university in 1890, the technical faculty changed its name to École d’Ingénieurs de l’Université de Lausanne. In 1946, it was renamed the École polytechnique de l’Université de Lausanne (EPUL). In 1969, the EPUL was separated from the rest of the University of Lausanne and became a federal institute under its current name. EPFL(CH), like ETH Zürich (CH), and it is thus directly controlled by the Swiss federal government. In contrast, all other universities in Switzerland are controlled by their respective cantonal governments. EPFL(CH) has started to develop into the field of life sciences. It absorbed the Swiss Institute for Experimental Cancer Research (ISREC) in 2008.
In 1946, there were 360 students. In 1969, EPFL(CH) had 1,400 students and 55 professors. In the past two decades the university has grown rapidly and over 14,000 people study or work on campus, about 10,000 of these being Bachelor, Master or PhD students. The environment at modern day EPFL(CH) is highly international with the school attracting students and researchers from all over the world. More than 125 countries are represented on the campus and the university has two official languages, French and English.
Organization
EPFL is organized into eight schools, themselves formed of institutes that group research units (laboratories or chairs) around common themes:
School of Basic Sciences
Institute of Mathematics
Institute of Chemical Sciences and Engineering
Institute of Physics
European Centre of Atomic and Molecular Computations
Bernoulli Center
Biomedical Imaging Research Center
Interdisciplinary Center for Electron Microscopy
MPG-EPFL Centre for Molecular Nanosciences and Technology
Swiss Plasma Center
Laboratory of Astrophysics
School of Engineering
Institute of Electrical Engineering
Institute of Mechanical Engineering
Institute of Materials
Institute of Microengineering
Institute of Bioengineering
School of Architecture, Civil and Environmental Engineering
Institute of Architecture
Civil Engineering Institute
Institute of Urban and Regional Sciences
Environmental Engineering Institute
School of Computer and Communication Sciences
Algorithms & Theoretical Computer Science
Artificial Intelligence & Machine Learning
Computational Biology
Computer Architecture & Integrated Systems
Data Management & Information Retrieval
Graphics & Vision
Human-Computer Interaction
Information & Communication Theory
Networking
Programming Languages & Formal Methods
Security & Cryptography
Signal & Image Processing
Systems
School of Life Sciences
Bachelor-Master Teaching Section in Life Sciences and Technologies
Brain Mind Institute
Institute of Bioengineering
Swiss Institute for Experimental Cancer Research
Global Health Institute
Ten Technology Platforms & Core Facilities (PTECH)
Center for Phenogenomics
NCCR Synaptic Bases of Mental Diseases
College of Management of Technology
Swiss Finance Institute at EPFL
Section of Management of Technology and Entrepreneurship
Institute of Technology and Public Policy
Institute of Management of Technology and Entrepreneurship
Section of Financial Engineering
College of Humanities
Human and social sciences teaching program
EPFL Middle East
Section of Energy Management and Sustainability
In addition to the eight schools there are seven closely related institutions
Swiss Cancer Centre
Center for Biomedical Imaging (CIBM)
Centre for Advanced Modelling Science (CADMOS)
École Cantonale d’art de Lausanne (ECAL)
Campus Biotech
Wyss Center for Bio- and Neuro-engineering
Swiss National Supercomputing Centre
sciencesprings 