NRP's Joint Synthesis on 'Electricity Storage via Adiabatic Air Compression' now online

Please find the National Research Programmes (NRP) joint synthesis on 'Electricity Storage via Adiabatic Air Compression' here: in English, in German and in French.

Summary: The phasing out of nuclear power plants and the expansion of solar and wind energy mean that electricity production is becoming more volatile. New storage systems are needed to ensure that electricity is available as and when it is required.

A promising technology for this purpose is adiabatic compressed air storage. It uses excess electricity from solar and wind energy systems to compress ambient air and store it in an underground cavity. When it is required, the compressed air is expanded again, driving a turbine and generating electricity once more. As the heat which was generated during compression is used for this process, the efficiency level stands at 65% to 75%, which is similar to that achieved by pumped-storage systems. The environmental compatibility of compressed air energy storage (CAES), in terms of the potential for emitting greenhouse gases and the damage inflicted on ecosystems, is also comparable to that of pumped-storage systems.

CAES systems are technically feasible. Important components such as turbomachinery and heat accumulators are either already available on the market or have been tested in a pilot plant. The process for constructing cavities is also well-developed due to the experience gained in tunnel and cavern construction.

Adiabatic CAES therefore represents an efficient, environmentally friendly and technically feasible storage solution. Due to the high capital costs and the unclear economic and legal framework conditions, however, it is uncertain whether they can be economically viable. This also complicates the financing of a demonstration plant.

White Paper Power-to-X Completed!

On July 8, 2019 the White Paper Power to X was officially introduced to the public.

In a joint research project of five Swiss competence centers for energy research, scientists of the Paul Scherrer Institute (PSI), the Swiss Federal Laboratories for Materials Science and Technology (Empa), ETH Zurich, the Zurich University for Applied Sciences (ZHAW), the University of Applied Sciences Rapperswil (HSR), the University of Geneva, and the University of Lucerne have prepared a white paper on "Power-to-X" for consideration by the Swiss Federal Energy Research Commission. The goal of the white paper is to gather together the most important insights available on Power-to-X technologies. Among other things, the study sheds light on contributions that could be made to Switzerland's energy strategy by different technologies based on conversion and storage of various forms of energy. The experts presented the findings of this study on July 8, 2019 at ETH Zürich.

The white paper and the full study are available for download.

in English, auf Deutsch, and en français

full report (in English).

Annual Report 2018 Published

The annual activity report of the SCCER HaE is available now on our web site. The Swiss Competence Center for Energy Research (SCCER) Heat and Electricity Storage is now in the middle of its second phase.

In this report, a detailed summary of our activities and achievements from 2018 can be found, giving our interested readers from academia, industry, and politics an overview of our successful operation. Following the lines of our technical roadmap, our progress reached new and highest standards. We invite you to explore the achievements of the 25 groups of the SCCER presented in our Annual Report 2018 (hig res.) or ( low res.). If you prefer, there are also carbon copies available upon request.

International Summer School "Power to X"

Fundamentals and Applications of Modern Electrosynthesis"

On August 27th - 31st 2018 internationally renowned researches from academia and industry shared their experience with a group of master, PhD students as well as post-docs and young scientists at the International Summer School "Power to X : Fundamentals and Applications of Modern Electrosynthesis"

organized by PD Dr. Peter Broekmann (University of Bern), Prof. Dr. Matthias Arenz (University of Bern) and Prof. Dr. Thomas Schmidt (Paul Scherrer Institut). The meeting took place in the heart of the Alpes Vaudoises - Villars, Switzerland. Click here for a report on this event.


Valuing dedicated storage in electricity grids

With contribution of the SCCER HaE, the European Academies Science Advisory Council (EASAC) released a report on roles and possibilities of storage in future electricity systems. In four main chapters, an overview on

  • Electricity storage technology with an assessment on their availability in 2020 and 2030;
  • Services given by storage to the electricity marked (EU perspective);
  • The status of modelling and assessing the value of storage; and
  • Policy options for future electricity market design to ensure the required flexibility of the electricity system;
  • together with a 12-item executive a summary for policy makers is given. Read get full study here.

Von Stromspeichern und Kompetenzzentren im Kontext der Energiewende

Interview with Thomas J. Schmidt on Im Rahmen der Energiestrategie 2050 werden Stromspeicher für die Stabilität des Stromnetzes und für dessen Versorgung künftig eine zentrale Rolle spielen. Dem Kompetenzzentrum SCCER Storage dürfte dabei eine wichtige Rolle zukommen. Read the whole article

Thomas J. Schmidt – Leiter des Kompetenzzentrums SCCER Storage am Paul-Scherrer-Institut

Nanomaterial helps store solar energy: efficiently and inexpensively

Field trials show that new catalyst material for electrolysers is reliable Efficient storage technologies are necessary if solar and wind energy is to help satisfy increased energy demands. One important approach is storage in the form of hydrogen extracted from water using solar or wind energy. This process takes place in a so-called electrolyser. Thanks to a new material developed by researchers at the Paul Scherrer Institute PSI and Empa, these devices are likely to become cheaper and more efficient in the future.

The material in question works as a catalyst accelerating the splitting of water molecules: the first step in the production of hydrogen. Researchers also showed that this new material can be reliably produced in large quantities and demonstrated its performance capability within a technical electrolysis cell — the main component of an electrolyser. The results of their research have been published in the current edition of the scientific journal Nature Materials. Read the full text here. Text and photos: PSI

Nano: Solar Heat from Summer carried over to Winter (German)

Fertig ist die Lauge Solarkraft aus dem Sommer im Winter zum Heizen verwenden: Heizen mit erneuerbaren Energien funktioniert nur mit Wärmespeicher. Eine Möglichkeit: Natronlauge.

  • Die Energiewende stehe erst am Anfang.
  • 70% der Haushalte werden mit fossilen Energieträgern beheizt.
  • Im Winter ist Solarenergie nicht ausreichend verfügbar und derzeit lassen sich die Überschüsse aus dem Sommer nicht speichern.
  • Mit Hilfe der Verdünnungswäreme von Laugen könnte hier abhilfe geschaffen werden. Hier geht es zum Video.

Nano: Adiabatic Compressed Air Storage (German)

Unter Druck Erneuerbare Energie durch Druckluft sichern: Erneuerbare Energien sind wetterabhängig. Mit Druckluftspeicherverfahren wollen Forscher deshalb Schwankungen im Stromnetz ausgleichen.

  • Neue Speichermöglichkeiten werde benötigt, da die Stromproduktion von Wind- und Solarkraftwerken Schwankungen unterworfen ist.
  • Bisher habe Pumpspeicher diese Aufgabe übernommen.
  • Druckluftspeicher haben minimale Auswirkungen auf das Lanschaftsbild.
  • Wirkungsrad über 70%
  • Mit Hilfe der Verdünnungswäreme von Laugen könnte hier abhilfe geschaffen werden. Hier geht es zum Video.

Highlights of Phase I

1 / 6
Type of storage centralized
Stored energy mechanical
Most economic cycle period hrs/days
Efficiency estimated: 70%
Status Demonstrator



2 / 6
Type of storage centralized
Stored energy mechanical
Most economic cycle period hrs/days
Efficiency estimated: 70%
Status Demonstrator



3 / 6
Type of storage centralized
Stored energy chemical
Most economic cycle period days/weeks
Efficiency estimated: 40%
Status Demonstrator



4 / 6
Type of storage decentralized
Stored energy chemical
Most economic cycle period hrs
Efficiency estimated: 90%
Status Proof of principle



5 / 6
Type of storage centralized
Stored energy chemical
Most economic cycle period days/weeks
Efficiency estimated: 60%
Status Proof of principle



6 / 6
A ranking for storage options, depending on cycle time is given.
At a system size of 1 MW, for short (< 1 min)
term storage battery systems are most economic and associates with the
least greenhouse gas emissions, while for medium term storage (day),
battery is still advantageous in terms of cost,
but not in terms of green-house gas emissions, Batteries fall
behind pumped hydro and adiabatic air storage.