An overview of The UK Energy Storage Research Network and ... · in the role of energy storage in...
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Transcript of An overview of The UK Energy Storage Research Network and ... · in the role of energy storage in...
An overview of The UK Energy Storage Research Network and Supergen Energy Storage
N. P. Brandon *
1Department of Earth Science and Engineering, Imperial College London, London, SW7 2AZ, UK
Research into energy storage involves multiple disciplines and covers a wide range of technologies and issues, from science, engineering and policy. The UK has a strong tradition in science and engineering relevant to energy storage, coupled with growing interest from industry and policy makers in the role of energy storage in both low carbon transport and low carbon energy systems. This has resulted in increasing recognition of the need to bring this diverse energy storage community together. To this end, the Research Council Energy Programme has funded two integrating programmes which bring together academia, industry and policy makers across the UK, and seeks to build links with international partners: the Energy Storage Research Network (ESRN) and the Energy Storage SUPERGEN Hub (Energy SuperStore). The presentation will provide an overview of the research and activities within these programmes, as well as offer an introduction to the speakers own research in flow, lithum and zinc-air batteries, including the use of tomography to resolve battery electrode microstructure.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -2-
Na-ion Batteries: New Challenges
C. Marino1, L.O. Vogt1, M. Kovalenko2, K. Fromm3, P. Novák1 and C. Villevieille*1
1Electrochemistry Laboratory, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland 2ETHZ, Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, CH-8093
Zürich, Switzerland 3University of Fribourg, Department of Chemistry, Chemin du Musée 9, CH-1700 Fribourg, Switzerland
In the last few years, research to determine the most suitable anode and cathode materials for Na-ion batteries has gained an increased attention. It was a great surprise to discover that pure commercially available elements such as Sb, Sn, or P1-3 can react electrochemically with Na, leading to sustainable reversible capacities as high as 500 mAh/g over more than 100 cycles when carboxymethyl cellulose (CMC) binder is used. These results were unexpected, especially if we compare them to the Li-ion systems. The most commonly used Li-ion binder, polyvinylidene difluoride (PVDF), was reported to not work in the sodium system but no further investigation was done to understand the chemical reasons. Recently, Dahbi et al.4 reported on Na-CMC binder for hard carbon electrodes in Na-ion batteries. They demonstrated better electrochemical results with CMC binder than with PVDF. They also reported that fluoroethylene carbonate (FEC) was essential as an electrolyte additive to improve the cyclability of the PVDF-based electrode.
For the first part of our study, we were intrigued by the poor cycling performance shown by PVDF in Na-ion batteries, as well as by the role of the FEC additive; thus, we chose Sn materials as a model conversion system, to understand the relationship between the surface and bulk properties. Post-mortem scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) studies of the electrodes were performed to get an insight into the surface properties, while in situ X-ray diffraction (XRD) was used to understand the bulk reaction mechanisms.
The second part of the talk is dedicated to the development of more advanced Sn-based anodes and the impact of the particles size on the electrochemistry, as well as the development of cathodes.
Finally, we will present the first results of full-cells batteries and demonstrate the concept of Na-ion batteries as potential new batteries.
References: 1Kim, Y. et al., Adv. Mat. 2013, 25, 3045. 2Baggetto, L. et al., Electrochem. Comm. 2013, 27, 168. 3Baggetto, L. et al., Journal of Power Sources 2013, 234, 48. 4Dahbi, M. et al., Electrochem. Comm. 2014, 44, 66.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -3-
Li-ion Batteries for Use in Public Transportation Infrastructure
T.J. Patey*
ABB Corporate Research, Segelhofstrasse 1 K, CH-5405 Baden-Dättwil, Switzerland
In this presentation, high power Li-ion battery use cases for public transportation are described (example in Fig. 1). Li-ion battery material and design are done to reflect these challenging power and lifetime requirements. A battery model which simulates electric, thermal, and aging behavior is introduced (Fig. 2) as a method to predict battery lifetime and to study the impact of system and design variables.
Fig.1 Example of an electric bus following a flash charge in Geneva, Switzerland (Source: http://www.tosa2013.com)
Fig.2 Overview of an electric, thermal, aging model,
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -4-
Modeling and Simulation of High-Temperature TES Systems
M. Barbato*
ICIMSI Institute – Department of Innovative Technologies SUPSI – University of Applied Sciences and Arts of Southern Switzerland - CH
High temperature Thermal Energy Storage (TES) is one of the key technologies for energy conservation. Initially exploited by solar energy plants for backup and dispatch purposes, it is nowadays a technological sector generating a renewed interest, a field where future energy production, distribution and management scenarios are bringing new research challenges. TES systems are usually large-scale apparatuses and hence their experimental testing is a very expensive process. Therefore, numerical modeling and simulation are of paramount relevance to push forward R&D activities in this field.
The speech will deal with modeling and simulations of single tank TESs. These are systems in which a thermocline region exists, i.e., systems where there is a relatively thin horizontal layer separating high and low temperature regions of the heat storage media. Modeling challenges related to TES based on packed bed of solid materials with air as Heat Transfer Fluid (HTF) will be presented. Void fraction distribution, packed bed transport properties, and time dependent fluid dynamics models will be illustrated in details and their application results will be shown for some specific test cases. Furthermore, a special case of a TES exploiting a combination of sensible and latent heat storage will also be discussed.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -5-
Sustainable Electrocatalysts for Hydrogen Production using Renewable Energy
K. Sivula*
Laboratory for Molecular Engineering of Optoelectronic Nanomaterials, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland
A challenge in the production of Hydrogen from renewable energy using water electrolysis at low current density (ca. 10 mA cm–2, especially useful for disperse renewable energy like solar) is the identification of inexpensive and scalable catalysts materials to reduce the overpotential required to drive the water oxidation and reduction reactions. While Platinum is traditionally used for the water reduction half-reaction, it is not scalable to the terawatt range necessary. Abundant transition metal compounds (e.g. MoS2) have been identified as promising replacements for Pt in this application. We have recently developed a novel way to solution process natural (bulk) MoS2 into thin film electrodes.1 Subsequently we have demonstrated that these electrodes have high activity for water reduction at low overpotential (0.2 V at 10 mA cm–2) even with only a few atomic layers of (solution-processed) MoS2. Moreover we have explored WSe2 as a layered photocatalyst for the direct conversion of solar energy into hydrogen fuel. Here we present a technique for the preparation of controlled thin-films of 2D WSe2 from dispersions of solvent-exfoliated few-layer flakes.2 Flake self-assembly at a liquid/liquid interface (formed exceptionally from two non-solvents for the WSe2) is followed by substrate transfer to afford large-area thin films with superior 2D flake alignment compared to traditional (liquid/air) interfacial self-assembly techniques. We further demonstrate, for the first time, solar-to-hydrogen energy conversion from solution-processed WSe2 thin films. Bare photoelectrodes with a thickness of ca. 25 nm are shown to exhibit sustained p-type photocurrent under simulated solar illumination. Photocurrent densities of ca. 1.0 mA cm–2 at 0 V vs. RHE are observed with an added water reduction catalyst (Pt). The importance of the self-assembled thin-film morphology on the performance is further established by photoelectrochemical and conductivity measurements.
References
1Yu, X.; Prévot, M. S.; Sivula, K. Chem. Mater. 2014, 26 (20), 5892-5899.
2Yu, X.; Prévot, M. S.; Guijarro, N.; Sivula, K., Self-assembled 2-D WSe2 Thin Films for Photo-electrochemical Hydrogen production. Under revision 2015.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -7-
(Electro) reduction of CO2: From Fundamentals Towards Applications
A. Dutta1, A. Rudnev1, M. Rahaman1, N.T.M. Hai1, T.M.T. Huynh1, A. Kuzume1, Y. Fu1, F. Stricker1, J. Furrer1 and P. Broekmann1*
1Department of Chemistry and Biochemistry (DCB), University of Bern, CH
Electrochemistry offers a highly promising approach towards the conversion of the green-house gas CO2 into more valuable products (fuels or precursors for chemical synthesis). The overall process efficiency and (product) selectivity of the CO2 electro-reduction crucially depends on the particular process parameters (current density, overpotential), the chemical nature of the catalyst and the electrolyte/solvent used. However, when carried out in aqueous environments the CO2 electro-reduction always competes with a parasitic hydrogen evolution reaction (HER) which finally determines (lowers) the current efficiency for the CO2 conversion. What is missing so far is a deeper mechanistic understanding of the CO2 electro-reduction as basis for a rational design of new and more effective catalyst materials. In particular advanced in-operando techniques are therefore needed that allow the structural and compositional analysis of the active catalyst under more realistic HER/CO2 reaction conditions. For selected copper model catalysts we demonstrate that it is actually the parasitic HER which alters the catalyst surface. Copper is one of the most superior catalyst materials for CO2 reductions owing to its selectivity towards hydrocarbon formation (fig 1). High-resolution scanning probe techniques applied under in-operando conditions clearly demonstrate massive changes of both the geometric and electronic surface properties of the copper catalyst due to the presence of sub-surface hydrogen. This H-intercalation in interstitial sub-surface sites during HER leads to concerted surface reconstruction/outward relaxation processes that are fully reversible. We have to consider this H-modified copper as the actual catalyst for the CO2 electro-reduction and not the bare, unreconstructed one. As a second example for the application of in-operando techniques we present a comprehensive in situ Raman spectroscopy study on graphene-supported SnOx NP-catalysts. SnOx NPs are superior catalysts owing to their high selectivity towards formate formation. The gradual chemical transition from SnOx NPs to metallic Sn particles can be monitored as function of the applied overpotential and the pH.
Fig.1: Reconstruction of a Cu(111) model catalyst due to H-intercalation under CO2 reduction/HER conditions
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -8-
sunfire Power-to-Liquids: Fuels and Chemicals from CO2, Water and Renewable Energy
Ch. von Olshausen1*, S. Becker1
1sunfire GmbH, 01237 Dresden, Germany
The sunfire project began in May 2012 and follows two main goals:
1. Construction and operation of a High-Temperature Electrolyser, which reaches an electricalefficiency level (LHV(H2)/kWel) of well over 90% (for 10kWel) under pressure.
2. Construction and operation of a pilot plant for the production of hydrocarbon from CO2 and H2Owith an efficiency level of >65% ((LHV(H2)/kWel).
The full process of the production of hydrocarbon consists in (1) Steam-electrolysis, (2) CO2-RWGS-conversion1 and (3) Fischer-Tropsch-Synthesis. After thorough lab-tasting of the process, the sunfire pilot plant was erected and presented to the public on 14 November 2014 in the presence of Minister Prof. Johanna Wanka.
Fig 1: First introduction of CO2 executed by Minister Wanka
Fig 2: High-Temperature electrolysis pressure tank
Fig 3: Overall view of the sunfire Fuel 1 – power plant
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -9-
Since the inauguration on 14.11.2014, the launched operation is now gradually moving forward. The strengthening of the high-temperature pressure insulation required greater revision after the thermal conductivity increased more than expected due to pressure influence.
During the project, the reversible fuel-cell / electrolyzer has been successfully operated and proves ground-breaking research results. This RSOC (Reversible Solid Oxide Cell) unit could become the pioneer of the PtX-business model, in that it is able to supply electricity in time of energy penury. As a result, a new source of income will be secured and the usage of the power plant will increase.
Figure 4: Reversible cycles of the Fuel-Cell / Electrolyser source: sunfire GmbH
In parallel to the technical developments underway, an Life Cycle Analysis of the concept’s whole supply chain has been undertaken by the University of Stuttgart. A report of the current state of the pilot plant has already been completed. This will be used to gage the ecological impact of the production of fuel on an industrial level.
In completing this project, the first steps will be made towards the industrialization of the Power-to-Liquids processes for the production of liquid fuels (Petrol, Diesel, Kerosene) compatible with various kinds of infrastructure through the use of the highly efficient steam electrolysis. Through this approach, for each ton of fuel produced, up to 3,14 tons of CO2 can be saved. Furthermore, the process can serve as a balancing power for the stabilization of the electricity network and can enable decentralized, regional added value coupled with a greater security of supply.
5 companies and 5 scientific institutes, specializing particularly in the fields of material development and process characterization, are working hand in hand on this project. In total so far, 11 Final-Year projects and Master theses have been written about this project.
1 Reverse Water-Gas Shift Reaction: Endothermal reduction of CO2 to CO under oxidation of H2 to H2O
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -10-
For more information, please visit:
www.sunfirefuel.com
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -11-
Development and First Application of an Assessment Method for Energy Storage
D. Parra1*, X. Zhang2, A. Abdon3, C. Bauer2, C. Mutel2, M. K. Patel1
and J. Worlitschek3
*[email protected] Energy Efficiency Group, Institute of Environmental Sciences, University of Geneva. Route de Drize
7-1227 Carouge (Genève). 2 Technology Assessment Group, Paul Scherrer Institut (PSI). CH-5232 Villigen PSI.
3 Lucerne University of Applied Sciences & Arts, Technikumstrasse 21, CH-6048 Horw.
A uniform methodology comprising techno-economic analysis and environmental assessment using Life Cycle Assessment (LCA) for electrical and thermal storage is developed and presented in this study, together with its first application for two different energy storage (ES) technologies, i.e. (a) power to gas and (b) battery storage. Scenarios are defined (schematically represented in Figure 1) to assess ES technologies, in which different reference energy systems (e.g. building/districts, industry and mobility) are considered, with different energy supplies to meet different demand loads. The benefits brought by ES are identified in each scenario, and the Swiss regulatory context including market and policy trends are considered in order to quantify the economic and environmental performance of ES technologies under different conditions.
Fig. 1: Diagram of Scenario Construction Fig. 2: Power-to-Gas system
The above-mentioned methodology is applied to a case study on Power-to-Gas (P2G) system. In LCA, parameterization of Life Cycle Inventory (LCI) data is performed for different processes in order to investigate how system parameters, such as the scale of the system, the supply of electricity and the operation conditions, will affect the environmental performance of the systems. We compare the GHG emissions of Power-to-Gas and conventional gas production technologies for hydrogen and natural gas. In Power-to-Hydrogen, the associated GHG emissions of electricity generation for electrolysis will to a great extent determine the GHG emissions of hydrogen production, whereas in Power-to-Methane, the source of CO2 (whether it is captured from biogenic or fossil-based emissions) will be a more important factor to consider in order to reduce the system emissions (Fig. 3). The operation conditions of the electrolyzer also have an impact on efficiency and GHG emissions: the larger the load density of electrolyzer (operation point on polarization curve) is, the higher the GHG emissions. But this should be considered with its trade-off on capital investment. As part of the techno-economic analysis, the levelised cost (CHF/kWh), levelised value (CHF/kWh) and profitability of Power-to-Gas plants systems are quantified in each scenario, with different plant configurations. While the levelised value of providing hydrogen and methane is always lower than the levelised cost, the analysis shows how alternative value propositions including other applications such as heat generation and frequency regulation contribute to achieve positive values for the internal rate of return.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -12-
The Energy Systems Integration Platform at PSI
P. Jansohn*
*peter [email protected]
Combustion Research Laboratory Paul Scherrer Institut 5232 Villigen, Switzerland
Renewable energy, available during times of low demand, might fail to reach the power grid and is a missed opportunity to protect the climate
The new Energy Systems Integration (ESI) Platform at PSI is investigating one possible solution to this problem: a technology known as “power-to-gas”, which involves converting excess renewable electricity into an energy-rich gas such as hydrogen or methane (synthetic natural gas). This enables surplus electrical energy to be stored in the form of chemical energy. The gaseous energy carriers can be kept for a long time and transported a large distance before being converted back into electricity or heat as and when needed. The power-to-gas concept consists of two steps: first, the surplus electricity is used to split water into hydrogen and oxygen with the aid of an electrolyzer. In the second step, the hydrogen is processed further into synthetic natural gas (methane) by adding CO2.
PSI has been researching individual components of the power-to-gas technology for many years, including polymer electrolyte membrane (PEM) materials and cathode catalysts, which form the core of the PEM electrolyze. PSI has also a wide expertise in methane production– especially from biomass. And thanks to the institute’s many years of research on fuel cells, combustion engines and gas turbines, PSI also has extensive experience in technologies for the efficient conversion of the stored gases back into electricity.
The focus of the ESI Platform is to study all of these components in their complex interplay at the system level for the first time. The goal is to realize a plant system with an output in the range of 100 kilowatts in order to gain system operation experience that goes beyond testing individual components. The aim of the plant is to explore the boundaries of what is technically feasible for power to gas, and the costs and possibilities of upscaling to a plant in the megawatt range.
Schematic representation of the ESI Platform at PSI.
Heat & Electricity Storage 2nd Symposium
May 5, 2015 -14-
