It is not just palm trees that flourish in the tropical sun, business ideas do, too – and this is definitely true for Enapter. The story of the AEM electrolyzer manufacturer began in Thailand. There, company founder Sebastian-Justus Schmidt lived in Chiang Mai and, around ten years ago, transformed his home into the world's first energy self-sufficient, solar-hydrogen-powered apartment building. To store solar power in the form of hydrogen, he used prototype electrolyzers from the former company ACTA, a pioneer of AEM electrolysis technology, which later became Enapter.
His experience as a user guided him in founding Enapter and further developing the systems – making them more compact and lightweight without compromising performance. This led to the creation of Enapter's first AEM electrolyzer. In an interview with Tim Cholibois, Vice President Strategy and Business Development, we learned more about AEM technology, its future prospects and Enapter’s product range.
When Enapter began operating seven years ago, we started with a stack with a power output of 2.4 kW. This is what is installed in our single-core electrolyzer. These systems are about the size of a microwave and are ideal for pilot projects and smaller applications. They can be combined in cabinets to create systems with a total output of up to 150 kilowatts. We firmly believe that entering the hydrogen business should be as simple as possible, and this is easier with small, scalable units. We have already delivered over 7,500 of these systems to our customers worldwide.
You can also combine our stacks and make larger systems within multi-core electrolyzers, though. Our “AEM Flex 120” model, for example, has an output of 120 kilowatts and consists of 50 stacks, while our “AEM Nexus 1000” container solution, with an output of 1 megawatt, consists of 420 stacks. Our goal remains the same – to be able to scale our systems on a modular basis, from micro-applications all the way to the megawatt range.
Our core product is the standardized and modular AEM electrolyzer (anion exchange membrane). Electrolyzers use electricity to split water into hydrogen and oxygen through an electrochemical reaction. The stack is the heart of the electrolyzer and consists of several cells connected in series in a bipolar design. These cells consist of a polymeric AEM and specially developed low-cost electrodes. The anodic half-cut cell is filled with a dilute alkaline electrolyte solution, while the cathodic half-cut cell contains no fluid. Instead, it produces hydrogen from water that permeates the anodic half-cut cell membrane. Oxygen is released from the anode side and transported out of the stack by the circulating electrolyte. The hydrogen is produced under pressure (35 bar). Using Enapter’s additional dryer module, 99.999 percent purity hydrogen is delivered.
Our electrolyzers combine the low-cost materials of alkaline electrolysis with the efficiency and flexibility of a PEM (proton exchange membrane) electrolyzer. Due to the less corrosive environment and the patented dry cathode, we can manufacture our electrolyzers mainly from nickel and steel. Plus, because we do not need to use platinum-group metals or the element iridium, which is rare and expensive, our products are already more cost-effective than PEM solutions of a comparable size.
Currently, alkaline and PEM electrolyzers dominate the market, while AEM technology is still relatively new. However, it does have the potential to capture a significant market share as it offers a low-cost basis and a simple supply chain.
One argument against PEM is that the predicted scaling of PEM electrolysis, which would be necessary to meet growing global hydrogen demand, cannot be realized with the quantities of iridium available each year. Our calculations show that the PEM industry would require many times more of the world’s iridium supply than is available. Due to the high cost of raw materials, widespread commercialization remains challenging. By contrast, according to analyses by the European Commission’s Clean Hydrogen Partnership, alkaline and AEM technology will be among the most cost-effective technologies in the future, while PEM technology will remain somewhat more expensive. In China, industry is already investing heavily in AEM technology.
In Germany and in other markets, many established manufacturers of PEM electrolyzers have also launched research projects on AEM electrolysis. However, we have the advantage of 20 years of research experience and a great deal of strong patents.
Since Enapter has its origins in Thailand, we are historically well represented in the surrounding countries. This is partly because our electrolyzers are particularly well suited for decentralized energy storage, which is hugely important for the region, as it has many remote communities and small islands.
In Malaysia, we installed one of our electrolyzers in a village in the jungle as early as 2019. Here, solar energy is converted into electricity during the day and then stored in hydrogen to ensure a flexible power supply. The major advantages our electrolyzers have are their compact design and how easy they are to install.
Another example is the Bangkok-based Electricity Generating Authority of Thailand (EGAT) Learning Center. It features a hydrogen energy system with ten AEM electrolyzers, two dryers, and a water tank module, all integrated into an indoor cabinet. EGAT serves as an educational and research center, providing the public with insights into the use of renewable energy while also preparing businesses for the country's future carbon-neutral energy targets. The Enapter system acts as a showcase for emission-free energy supply for buildings.
With these systems, which are already market-ready and sold by our partners, we want to enable more energy independence at home. These solutions still require a high level of investment for consumers and it will take some time before they are affordable for everyone. Some countries are supporting such ideas and offering subsidies. However, it is more likely that green hydrogen will first establish itself in the building sector as part of district or municipal energy storage solutions.
I see two main uses for hydrogen in the German energy system – hydrogen can make the energy system more flexible and be provided as long-term energy storage. There are a number of challenges to be overcome in the energy transition. For example, the power grids could be overloaded because wind power is mainly generated in the north and has to be transported to the industrial centers in southern Germany. The necessary expansion of the power grid to improve logistics will require a great deal of investment. Plus, the share of renewable energies will fluctuate so much that the grid load will not always be covered sufficiently, especially at peak loads. To balance these peaks, excess electricity can be converted into hydrogen.
Enapter offers support in these scenarios, as our electrolyzers are designed to ramp up and down quickly in a matter of seconds. Combined with battery storage, an energy system can be optimized for renewable energy use.