This is a guest post by Dr. Kathrin Goldammer. The interview reflects their opinion and does not necessarily represent the opinion of the VDE.
Wind power and solar to hydrogen - sensible way in the energy transition
Appel: Let’s begin with a brief description about yourself: How are you connected with the topic of hydrogen?
Goldammer: I am an electrical engineer and therefore I am particularly involved with green hydrogen as it is produced from renewable energies and electricity via so-called electrolysis.
Appel: The current production process for hydrogen is primarily based on fossil energy sources. Even before the current situation in Europe, it was clear that this process was no longer in keeping with the times due to its impact on the climate. Which production process do you consider to be the most sustainable when it comes to meeting climate protection targets?
Goldammer: In my opinion, wind power and solar energy will play the biggest role – which is why electrolysis is the most important process on the road to the hydrogen of the future. Other processes such as direct power generation from exhaust gases or biogas will never be able to cover our long-term energy targets, and therefore do not represent forward-looking alternatives.
Electrolysis makes it possible to decarbonize the entire world of molecules through chemical processes. We will generate electricity from wind turbines and photovoltaic technology and then produce green hydrogen from electrolysis. From solar or wind energy to electricity, all the way through to the molecules – several conversion steps are required here, but I still see this as the most sensible way for hydrogen to contribute to energy production.
Less Grid Expansion and Simultaneous Grid Flexibility through Hydrogen
Appel: Put simply, by producing hydrogen we are initially integrating further consumers of electricity into our energy system. With increasing, fluctuating renewable energies, it is becoming more and more important to enhance flexibility in the grid in order to also keep grid expansion within reasonable limits. What role do you think hydrogen can play in this context?
Goldammer: Since electricity has to be “consumed” immediately, storage facilities are required. They can be used to decouple the electricity from the grid and make it usable again later. Hydrogen provides for exactly that. On the one hand, it can be stored better than electricity and, on the other hand, it decouples electricity production and demand from one another in terms of time: it can be filled directly into different containers – from a small bottle into a larger one, all the way up to a gas cavern.
In this case hydrogen is a flexibility option for the grid, because we can convert quantities of electricity into hydrogen and store it in this manner. However, it is also possible to store the electricity directly in electrochemical batteries. Hydrogen and batteries are certainlyin a competition here. If battery technology develops significantly, becomes more economical, is able to convert higher amounts of electricity and feed it into the grid, then it will become established as a flexibility option, and hydrogen will probably play a greater role in the area of long-term storage – bridging days or weeks – and power-to-X.
Incentives – Opportunity and Obstacle for a successful Hydrogen Economy
Appel: Not all hydrogen production plants will be able to be flexibly integrated into the grid in the future, because consumers are obviously dependent on the hydrogen supplies. But, for municipalities, for example, grid-serving operation can be worthwhile. In this case electrolyzers serve as flexible load management on the demand side to respond to the fluctuating RE production. Under what conditions can we increase the still low profitability of electrolyzers at this point via grid-serving operation?
Goldammer: We have just conducted a study on decentralized electrolyzers and found that grid areas with a very high share of renewables can be economical already today. Normally, a grid area with a high share of renewables has to greatly expand distribution or medium-voltage grids, for example, in order to be able to absorb these high volumes of electricity. Electrolyzers can remedy this situation and at the same time increase economic efficiency. The only problem is that the grid operator, for example, cannot operate electrolyzers. The reason for this is the so-called incentive regulation, which does not allow the operator to compare the options that exist, such as laying a cable and installing an electrolyzer. Thus, we need more incentives for a kind of overall grid planning and a systemic view of how electricity grids, gas grids and future hydrogen grids can be operated together economically.
Appel: That’s a good transition to the next question, because it’s not just the electricity grid that will include hydrogen in the overall portfolio in the future, but also the gas grid. This is where the heating market often comes up. Will consumers have to replace their widely used gas heating systems with new ones if the proportion of hydrogen in the gas grid increases?
Goldammer: The question is, how realistic is the scenario of sticking to this kind of thermal conversion, which in the future might combine methane or natural gas mixtures with green hydrogen instead of conventional natural gas. All studies that I am familiar with in this regard show that there will only be a few buildings where this is ultimately the most economical option. For most buildings it is more economical to use an electric form of heating such as air-source or geothermal heat pumps. At the moment, therefore, I do not yet see a large share for hydrogen when it comes to heat generation, instead I ask myself what will the future business model for today’s gas grid operators look like.
Comparison of Direct Electricity and Hydrogen Reconversion
Appel: What is your ultimate assessment of the option of converting hydrogen back into electricity?
Goldammer: I can’t imagine such an option in the household or commercial sector nor in the sphere of small, decentralized plants. In my view, electricity will probably be used here directly and hydrogen will only show up in rare cases. On the other hand, it is quite conceivable for the overall energy system in terms of classic power-to-X and bridging a period where solar/wind power generation is very low. That is, if we have almost one hundred percent renewable energies in the electricity sector by 2040 or 2050.
Appel: Can you imagine reversible, grid-connected fuel cells on a municipal level instead? They produce hydrogen and provide reverse power generation because they are integrated in both directions.
Goldammer: In this case I would initially wait for further studies and examples. At the moment I don’t see very much of a need due to the numerous direct power options that exist. Coming from the electricity sector, I think there will be more and much faster development here than in the fuel cell sector.
Appel: The focus of hydrogen requirements is currently placed on applications in the industrial sector, such as the chemical, steel or paper industries. I understand from what you have said that the need for reverse power generation will also play a role?
Goldammer: Yes, but in my opinion increasingly in the context of maintaining the power supply and less in the context of an application.
The Importance of Standardization for Grid-supporting Integration of Hydrogen
Appel: How can standardization help prepare the existing energy infrastructure for increased hydrogen feed-in and to improve grid-serving deployment?
Goldammer: My understanding is that standardization helps with compatibility and interoperability, as well as when it comes to proper decision-making. It provides assurance that certain technical measures will hold up and match other components. To me this means that a lot of potential will be lost in the context of new technologies or techniques if we fail to clarify the most important standardization issues until it is very late in the game. That will delay the rollout of all new technologies, be it electrolyzers or admixture in the gas grid. All of these things have yet to be prepared for the term “hydrogen economy.” The very fact that we can’t even precisely define what green hydrogen is demonstrates that there is still a lot to be done. Standardization can help to speed things up here.
Expansion of Renewable Energies is the Beginning
Appel: What is your final assessment of the designation of hydrogen as the “oil of the future”?
Goldammer: I’ve heard a lot of designations for hydrogen, such as the “champagne” or even the “cheese” of the energy transition. The latter was emphasized only recently by my colleague because hydrogen, like cheese from milk, is a conceptual product made from renewable energies.
In my opinion, all of these terms may be used as long as they make it clear that hydrogen is a rare product that should be used carefully. It is important not to forget what hydrogen will be produced from in the future – namely renewable energy. Therefore, finding a term that pays even more attention to the need for renewables would be even more preferable to me. The fact that a hydrogen economy will not work without the expansion and promotion of renewable energy is often lost in the discussion. Here it is important to learn to walk before we can run.
Appel: Those are excellent closing words. Ms. Goldammer, thank you very much for the interview!
Editorial notice:
The original article first appeared on the DKE LinkedIn channel: Limits and Opportunities of a Grid-serving, green Hydrogen Economy | LinkedIn
Author Information
Dr. Kathrin Goldammer is an expert in energy economics and energy technology. As Managing Director of the Reiner Lemoine Institute in Berlin, she is responsible for its scientific and commercial management.
She studied electrical engineering and received her PhD in physics in 2007; she then began her career in the energy industry. In 2018, she also founded the company Localiser RLI GmbH, which develops software for charging infrastructure planning for electric mobility.
Kathrin Goldammer holds various honorary positions, including being the representative for the Berlin-Brandenburg Energy Technology Cluster since 2021. She is a member of the scientific advisory board of the conference “Drives and Energy Systems of Tomorrow” of the Automobiltechnische Zeitschrift (ATZ). Ms. Goldammer is also a member of the advisory board of the Leibniz Research Network Energiewende. She is a former member of the board and currently regional manager of Hydrogen Power Storage & Solutions East Germany e. V. (HYPOS) and was part of the founding team of Women in Green Hydrogen in 2020. In December 2021, Kathrin was appointed to the Advisory Board for the Hydrogen Roadmap of the State of Baden-Württemberg for two years.
