Talks

Hydrogen

The storage of renewable energy for mobility and for seasonal energy transfer are the major challenges. While hydrogen storage reaches the highest gravimetric energy density for a fuel the hydrocarbons are high in gravimetric and volumetric energy density. Furthermore, in view of economic measures, batteries cost around 200 Euro/kWh, hydrogen costs 0.25 Euro/kWh and synthetic hydrocarbons around 0.3 Euro/kWh. Hydrogen absorbed in hydrides exhibits almost twice the density of liquid hydrogen is at moderate pressure and can be stored over a long time without any loss. The research on hydrogen storage focuses on new materials consisting of light weight elements and high hydrogen density. With the discovery of the complex hydrides, i.e. alanates and the borohydrides, as storage materials the potential gravimetric hydrogen density was increased by an order of magnitude...

Synthetic Fules


Major challenges that currently prevent electrochemical CO2conversion technology from being implemented into industrial applications are related to the enormous overpotentials needed for CO2 activation, thus typically resulting into a poor energy efficiency of the entire full cell-level process. Among the vast number of materials screened so far, it is Cu which deserves particular attention since it is the only catalyst which is capable to convert CO2 into hydrocarbons and alcohols. Crucial for the performance of the Cu catalysts is their pre-treatment ...

Electricity is moving from being one of the most expensive energy carriers to that with lowest cost, with solar generation offering highest energy utilization and smallest footprint. There is currently the potential for large scale electrification of the energy system, depending on policy, technology and market developments. In the event large scale electrification of energy supply would happen, new connections will need building - from power to heat and from power to mobility. However, electrification of the energy system is technically not simple, because electricity is relatively difficult to store and transport - this is in particular a problem in dealing with large variations in demand (winter/summer cooling/heating) as well as the intermittency of supply. The expectation is that a molecular energy vector is needed and the simplest solution would be hydrogen. Hydrogen could become an energy vector - linking increasingly electricity based supply with the various demand sectors; while also enabling long distance transport. In principle we could go further - hydrogen can serve as building block to also synthesize liquid fuels - very much needed in commercial transport and air transport as well as chemicals. Solar to energy technologies include: Solar PV*, Solar thermal*, Wind, Hydro, Bio-energy and Solar fuels.

Batteries


We all know that we need to change some things if we want to preserve our planet. Unfortunately, the average stationary battery system is relying heavily on mining and refining in sensitive habitats and is anything but green. JenaBatteries creates revolutionary organic redox-flow-batteries based on metal-free energy storage materials, salt and water, which reduce the environmental impact and can be manufactured at a much lower cost. The redox-flow-battery systems are based on metal-free storage materials that are produced in bulk already and require only common base chemicals as starting material. They are starting at a capacity of 40 kilowatt hours, but go up to several tens of megawatt hours. Power and capacity are scalable, independently of one another, which makes it possible to tailor the system to the customers’ needs. The battery’s lifespan is above 10,000 cycles and impresses with no self-discharge. The battery is also operable without active cooling between zero to 60 degrees, which again saves costs, especially in warmer countries....

Today, there is a gap between battery material development and system development for Swiss battery manufacturers and research institutions. Therefore, it is not possible to produce an application sized battery cell in a reproducible way at quantities large enough for qualified testing. The development of the pilot line closes this gap. On the other hand, there is a growing market for batteries for mobile and stationary applications, demanding for large sized battery cells. The production process for those type of cells is by far not optimized in terms of methodology and sometimes it still contains manual steps. Consequently large sized cells are 30% more costly than consumer cells. An elimination of such inefficient steps and alternative production methods will bring quality improvements and cost advantages. The Swiss manufacturing systems engineering industry, an export oriented economy, benefits from the possibilities to develop and export production equipment for batteries. I.e. Bühler AG has the novelty of continuous slurry mixing. The pilot line developed at BFH offers the opportunity of process technology development for Swiss industry together with Swiss battery research. In this talk, the motivation of the activities around the pilot line is discussed and the status of the setup explained.

Demonstrators


ehub is an energy research and technology transfer platform aimed at optimizing energy management at district level and evaluating its influence on the overall energy system. In conjunction with the other Empa demonstrators NEST and move, ehub can be used to combine energy flows in the mobility, housing and work sector, test new energy concepts under real-world conditions and explore the potential for increasing efficiency and reducing CO2.
The seamless integration of renewable energy sources, efficient storage possibilities and a dynamic interplay between a wide range of technologies is pivotal for a sustainable energy future. ehub, Empa’s Energy Hub demonstrator, displays a large number of technologies for the production, conversion, transportation and storage of energy. NEST provides a kind of vertical neighborhood for research on new energy concepts for networks of buildings. ehub comprises a wide variety of components, three thermal networks, three electrical networks and two gas networks. More information with the focus on the thermal aspects are given in the talk or in general on the web page of the project.

The growing share of intermittent renewable energy sources such as wind and solar requires short- and long-term energy storage to guarantee the power supply. At present, pumped hydroelectric stor-age (PHS) accounts for the majority of bulk storage capacity. The construction of additional plants is hampered by high capital costs and restrictive site requirements. Advanced adiabatic compressed air energy storage (AA-CAES) is so far the only alternative that can compete in terms of capacity and efficiency and has the advantages of lower expected capital costs and less strict site requirements. The basic principle underlying CAES has been demonstrated through the diabatic CAES plants in Huntorf (321 MW, Germany) and McIntosh (110 MW, USA). In these plants, the heat of compression is wasted and must therefore be resupplied prior to expansion, resulting in relatively low cycle efficiencies of about 45-50%. By contrast, in AA-CAES plants, the thermal energy generated by compression is stored in a thermal-energy storage (TES), increasing cycle efficiencies to about 70-75%. In the presentation, the authors will show experimental results from the world’s first pilot-scale AA-CAES plant using a rock cavern and combined sensible/latent TES and compare the results with data from simulations. The pilot plant was built near Biasca in an unused tunnel and demonstrated the technical feasibility of the AA-CAES concept, the use of rock caverns, and the combined TES at high temperatures.

Two examples of pilot plants for the production of synthetic hydrocarbons are presented. First, the design and build of a demonstrator for the conversion of solar energy to synthetic hydrocarbons is presented. The average power of the installation is set to 2 kW, which corresponds to the global energy consumption of a single person. The main components of the system are photovoltaic cells, batteries, an electrolyser, a metal hydride storage and compression system, a CO2 capture unit and chemical reactors. The installation allows studying the energy flows and reservoirs and the interaction between different components, comparing the performance of competing technologies and establishing an energetic and economic database from the real world. Further, the operating parameters such as pressure, temperatures and energy flows are recorded at different locations to enable for system modeling and advanced optimization techniques to be applied on real data. Last, the degradation of the various components will be investigated under actual working conditions ...

There are four Power-to-Gas demonstrators integrated in SCCER HaE phase ll.
The involved four academic groups work on the same objective, which is to design improved power-to-gas systems using state-of-the-art technologies and to bring them to TRL 6.
In 2017, the academic partners designed, ordered and installed their research equipment. Several meetings were organized in order to exchange the experience and preliminary results. It is planned to compare the demonstrators with each other. Results are expected as from 2018.
As a perspective for the end of the SCCER HaE phase ll the academic partners involved in WP5.4 will jointly release their results, especially on the specific efficiencies of their Power-to-Gas technology.