PSI expertise boosts research for the energy transition

Against the backdrop of the new National Research Programme “Energy Turnaround” (NRP70) of the Swiss National Science Foundation, PSI is helping to solve open scientific and technical questions related to the Energy Strategy 2050. The Swiss Federal Council granted the programme with a financial framework of CHF 37 million. Moreover, the federal government is also scrutinising regulatory and social aspects of the energy transition in another National Research Programme, the NRP71 "Managing energy consumption". Both programmes are due to run until the end of 2018.

Researchers from the Paul Scherrer Institute (PSI) are involved in several projects under the new National Research Programme “Energy Turnaround” (NRP70) of the Swiss National Science Foundation (SNSF). The PSI experts tackle issues such as particle emissions from wood heating systems, the holistic evaluation of energy systems and the production of semiconductor components for novel transformers.

Against the backdrop of the new National Research Programme “Energy Turnaround” (NRP70) of the Swiss National Science Foundation, PSI is helping to solve open scientific and technical questions related to the Energy Strategy 2050. The Swiss Federal Council granted the programme with a financial framework of CHF 37 million. Moreover, the federal government is also scrutinising regulatory and social aspects of the energy transition in another National Research Programme, NRP71. Both programmes are due to run until the end of 2018.

Research projects in the fields of “Building and settlement”, “Electricity supply”, “Industrial processes” and “Transport and mobility” are to receive financial support under the new NFP70 “Energy Turnaround”. The aim is to produce practical results that can be used in Switzerland in the next 10 to 30 years.

PSI’s contributions concern several projects. In one project, for instance, PSI researchers from the Laboratory of Atmospheric Chemistry are studying the impact of the use of wood heating systems for health and the environment. Compared to fossil energy sources, wood is a virtually CO₂-neutral fuel as wood burning only releases as much CO₂ as the trees have previously “breathed in” from the air. However, pollutants such as soot and fine dust also form during combustion in wood heating systems. A team of PSI scientists headed by Josef Dommen from the Laboratory of Atmospheric Chemistry are using their expertise on the formation of fine dust to help develop more environmentally friendly wood-burning heating systems.

A project with the involvement of PSI’s Laboratory for Energy Systems Analysis is tackling the risks arising through the use of heat from deep underground (deep geothermal) and hydropower. These two energy sources are to take on an increasing proportion of Switzerland’s energy supply under the new energy policy. However, they are not without their risks either. The project in question should help estimate these risks in different scenarios and highlight strategies to deal with them.

PSI expertise on energy systems analysis is also being channelled into a project concerning low-CO₂ heating and cooling in buildings. The PSI researchers’ task here is to evaluate the sustainability of an innovative heat-pump technology. Heat pumps are machines that raise low-temperature heat to a higher temperature level that can be used for heating, for instance. Electric heat pumps are currently booming in Switzerland. Nevertheless, the energy consumption is also increasing as a result, and the associated electricity demand is so irregular that it is placing a heavy strain on the power grids. Heat pumps that are powered by combustion engines, however, cause considerable CO₂ emissions. Scientists are now turning to sorption heat pumps to find a solution with a reduced consumption of electricity and fossil fuels. Sorption heat pumps use renewable heat – such as from solar collectors – or waste heat from industrial processes. Specifically, the project is focusing on technology based on porous solid materials, which can absorb relatively large amounts of a liquid in their pores. If heat is added, the liquid is forced out of the solid material. Heat is absorbed or released in these processes, which means that the heat pump can be used for both heating and cooling.

In another project, PSI scientists are concerned with a promising technology for the storage of large amounts of energy. It involves compressed air storage power stations, which, thanks to their large storage capacity, are regarded as a possible alternative to pump storage power stations in Switzerland. In compressed air storage, excess power is used to compress air and store it in caverns. In doing so, the electrical energy is stored in the compressed air. The compressed air can be channelled into a turbine that drives a power generator as and when needed. Only two compressed air storage power stations currently exist worldwide. Conventional technology involves relatively high energy losses because heat is generated during the compression of the air and released into the surroundings. When removed from the store, the air expands and cools down further. With the new technology, so-called adiabatic compressed air storage, the idea is to capture as much of this waste heat as possible. Innovative heat storage concepts are currently being developed with this in mind. The PSI contribution headed by Peter Burgherr is aimed at assessing this adiabatic compressed air storage and its prospects of a practical application in Switzerland from an ecological and economic perspective.

Finally, PSI knowhow also stands behind a project centred on novel transformers for an efficient and intelligent electricity distribution. Entitled “Swiss Transformers”, the project’s objective is to develop novel transformers based on the semi-conductor silicon carbide (SiC). The overall efficiency of these transformers is projected to be comparable to that of their conventional counterparts made of copper and iron. What is special about the new SiC transformers, however, is that they respond quickly to changes in the characteristic parameters of the electricity in the grid. As a result, they guarantee that the power grid remains stable, even with a heavily fluctuating supply of wind and solar power. Another plus point with regard to the future: thanks to the SiC transformer, direct current sources such as photovoltaic plants, batteries and charging stations for electric vehicles can be integrated in the AC grid. A team of researchers from the Laboratory for Micro and Nanotechnology at PSI headed by Jens Gobrecht has accepted the challenge to develop a cost-effective, reliable production process for the necessary SiC components, which are supposed to be usable at a voltage of 3.3 kilovolts. This is a challenging task as hardly any research has been conducted on the SiC processing technology at such high voltages to date.

Text: Paul Scherrer Institute/Leonid Leiva