Your Challenge:
Long-Duration Energy Storage

Hello people with radical new ideas! We need breakthrough innovations to store energy. Long-term. Efficiently. Cost-effective. We need bold ideas. We need you.

To play its part in the fight against climate change, Germany must become climate-neutral by 2045 and secure its energy supply exclusively from renewable sources. The pressure to act has also increased as a result of the Ukraine war, as gas has lost its appeal as a transitional technology and - and Germany's independence in terms of energy supply has become massively more important. In view of these new existential threats, the increasingly frequent natural disasters and extreme weather events, the share of renewable energies must rise sharply over the next two decades. At the same time, baseload nuclear and coal-fired power plants are to be completely taken off the grid by 2038 and replaced by wind and solar power.

In this context, long periods without significant solar and wind energy potential pose a particular challenge, so-called dark lulls. During these dark lulls, the output of wind and solar power is only a fraction of the usual average output, so that the energy demand cannot be met even with the help of load management and short-term storage. In Germany, several dark lulls with a length of more than 48 hours occur per year, but in individual cases they can also last for up to ten days. During these periods, long-term energy storage, i.e. energy storage with a storage duration of at least ten hours, plays an essential role in ensuring the stability of the power grid. In addition, long periods usually extend through the winter, during which energy generation will lag behind energy demand in the future.

Long-term energy storage is a central building block for energy autonomy and the achievement of climate targets, and at the same time a growing multi-billion market, which, however, can only be served inadequately with the currently market-ready technologies.

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The Challenge: Store energy and efficiently provide power for more than ten hours without using critical raw materials.

The Challenge will identify breakthrough technological approaches that enable long-term, efficient, and cost-effective energy storage. Key factors are raw material and system costs, self-discharge, storage efficiency, lifetime, energy density, and technical and economic scalability of the project idea.

We support:
Breakthrough innovations

Teams participating in this Challenge are fully challenged. SPRIND therefore provides intensive and individual support. This includes funding the teams with up to €1 million in Stage 1 of the Challenge and up to €3 million in the 2nd and final Stage. In order to help the teams develop their full potential, SPRIND provides them not only with financial support but also with a coach who accompanies, advises and networks the work of each team.

To enable the teams to concentrate fully on their innovations, we provide funding quickly and unbureaucratically. At the end of the first stage of the Challenge, after one year, the jury decides on the basis of interim evaluations which teams will continue to participate in the Challenge. As finalists, these teams are given the opportunity to drive their project forward for another year and a half and to comprehensively demonstrate their breakthrough.

Thinking one step further: Ideas with the potential for a breakthrough innovation must be brought to market to benefit us all - promising projects in this sense can therefore continue to be supported by SPRIND after the Challenge has ended.

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Start of the 2nd stage

In November 2023, the expert jury selected the participants for the second and final stage of the 'Long-Duration Energy Storage' challenge. Four teams will each receive up to 3 million euros over the next 18 months for the further development of their long-term energy storage technology.

Reverion

The new energy world is binary, says Felix Fischer: There is either a surplus of electricity or a shortage. When the sun shines, electricity prices fall; when it doesn't, prices rise, and the rapid provision of stored energy becomes increasingly important.

HalioGen Power

Thin walls protect redox flow batteries from short circuits while allowing ion exchange between the electrolytes: Membranes have been used in batteries for decades. But this could change.

Ore Energy

Unbound Potential

Radically simple design – that's the secret behind Unbound Potential's new flow battery. The company is working on a membrane-less battery to rival lithium-ion batteries.

Science Youtuber Jacob Beautemps was on site at the Challenge Team Unbound Potential at Breaking Lab.

Breaking Lab introduces Unbound Potential

The Jury

Gitanjali DasGupta

Sebastian Scholz

Anna Grevé

Pasquale Salza

Pilar Gonzalez

Nick de la Forge

FAQ

Do you have any questions about the Challenge? Write to us at challenge@sprind.org.

THE RUST OF THE FUTURE

How Ore Energy makes batteries breathe

Iron, air and water: Ore Energy is using these three elements to revolutionise the battery industry. The team's iron-air battery is designed to provide 100 hours of power and to step in when no renewable energy is available.

Ore Energy's battery consists of a water-surrounded iron anode and a membrane-like cathode. During discharge, oxygen enters the battery through the membrane. This 'inhalation' causes the iron anode to rust and the oxidation process releases energy. Conversely, when energy is supplied to the battery, the charging process regenerates the anode and oxygen is exhaled through the membrane. The battery is like a lung that breathes in and out, turning iron into rust and vice versa, explains Dr Aytac Yilmaz, co-founder of Ore Energy.

Although our anode material is based on iron, the material we use is completely different from anything that has been used before.

If you look at a rusty bridge, for example, it is a very stable form of rust. It's very difficult to turn it back into iron, explains Yilmaz. But not all rust is the same: whether it is reversible depends on its conditions.

Iron-air batteries are not a new invention. The concept was developed in the 1960s. However, it has been difficult to implement because iron rusts easily, but the process is difficult to reverse.

So how does Ore Energy create reversible rust? Although our anode material is based on iron, the material we use is completely different from anything that has been used before, Yilmaz says proudly. What other materials are hidden in the anode remains a company secret.

So let’s talk about the cathode: The cathode is essentially a membrane that allows oxygen to flow in and out. This happens through a special structure, says the 35-year-old and continues: There is a region on the membrane that we call the triple phase boundary. This is where the solids of the membrane meet the electrolytes, water on one side and air on the other. And this is where the reaction takes place that allows the battery to 'breathe': When discharging, oxygen is reduced to hydroxyl ions; when recharging, the hydroxyl ions become oxygen again.

Behind the battery, which is housed in a large container, is an expanding team of currently 30 people from 14 nations. Yilmaz himself was born in Turkey, studied in the USA and did his PhD in materials science in the Netherlands. There he began to work on the new iron-air battery.

Iron is cheap, so we will be able to offer a very low-cost battery, which is a key advantage over other batteries, says Yilmaz, adding: The cost is only 16 euros per kilowatt hour. By comparison, the price of lithium-ion batteries in 2023 was 10 times higher.

Another advantage is the safety of the battery. It is neither toxic nor flammable. The capacity is said to be several megawatt hours, and the efficiency is in the range of flow batteries. Yilmaz estimates that the battery will last 20 years, after which the iron can be recycled. The battery is modular and expandable, and is aimed primarily at utilities looking for a grid-connected application.

It quickly became clear to Yilmaz that the scientific findings could become an effective technology that needed to be transferred to society. But leaving the university was a challenge: We do excellent research in Europe. If you look at the high-impact papers, Europe does very well compared to the US or the rest of the world. However, if you look at the number of companies that come out of the university and are successful, it's significantly lower, especially compared to the US. This is a problem that needs to be addressed, says Yilmaz, summing up the problem.

SPRIND's Long Duration Energy Storage Challenge came at just the right time for Ore Energy. We were at the very beginning and SPRIND's support gave us a decisive boost. It has allowed us to grow much faster and develop our technology much more quickly, recalls Yilmaz, CEO of Ore Energy.

Ore Energy plans to produce the battery on a pilot scale next year. The next big challenge is scaling up. Yilmaz can't move fast enough because time is of the essence: Climate change is the biggest problem facing humanity. If we want to achieve the energy transition, we have to start yesterday.