Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Techno-economic analysis and optimization of electrochemical energy storage solutions
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The need to integrate the rapidly growing share of variable renewable energy sources in the power sector requires solutions that are capable of mitigating the intermittent nature of these sources. They are expected to constitute the backbone of the electricity generation system in the coming years in order to reach ambitious goals in terms of energy security and reduction of environmental impact. Energy storage appears a promising solution to improve the capability of variable renewable plants to meet the energy demand at all times, mainly through the re-allocation of the generation surplus.

Among the several options that can favor the integration of variable renewables, electrochemical storage technologies - batteries and electrolysis cells - constitute the focus of this dissertation. These approaches can be used to defer substantial quantities of energy for medium to long time intervals, are largely location independent, and are considered a strategic part of the decarbonization pathway in the European Union, which represents the geo-political framework under investigation.

Battery storage systems are analyzed in both small- and large-scale settings to quantify the energetic and economic benefits deriving from a more efficient use of renewable energy. A small-scale battery system connected to a residential PV plant is analyzed and the results are compared to a demand response strategy for load shifting. The integration of a large-scale battery facility in the energy system of an island is also simulated and the results show a much lower level of renewable energy curtailment. In both the situations the projected costs of the battery technologies are used to assess their techno-economic performance.

Solid oxide electrolysis cells (SOECs) as employed in power-to-gas upgrading of biogas constitute the second electrochemical energy storage pathway that was studied. The upgrading process sought to increase the methane content in the biogas by directly converting the embedded carbon dioxide through high-temperature electrolysis and methanation. This process showed energy conversion efficiencies higher than 80%. However, its economic viability depends on the cost of electricity, the cost of the core components, and the price of natural gas.

Abstract [sv]

Behovet för integrering av förnybar energis ökande andel inom elkraftssektorn innebär lösningar som kan hantera dessa energikällors oregelbundenhet. Förnybara energikällor förväntas att bidra till elkrafts ryggrad inom de kommande åren för att kunna nå de ambitiösa målen gällande energisäkerhet och förbättrad miljöprestanda. Energilagring är en lovande teknik för att underlätta förnybara energikällors möjligheter att tillgodose energibehoven dygnet runt, primärt genom omallokeringen av överskottsel.

Bland de olika alternativen som kan öka integreringsgraden av förnybara energikällor är elektrokemiska lagringstekniker – batterier och elektrolysörer – i fokus i denna avhandling. Dessa enheter kan användas för att flytta en del av energin inom mellan- och långtidsintervaller, är i huvud sak oberoende av placeringen och är en strategisk del av EU:s plan för minskning av koldioxidutsläpp. Det senare omfattar avhandlingens geopolitiska ramverk.

Batterilagringssystem är analyserade i både små- och storskaliga faller för att kvantifiera de energimässiga och ekonomiska fördelarna med en mer effektiv användning av förnybar energi. Ett småskaligt batterisystem kopplat till villabaserade solceller analyserades och resultaten jämfördes mot en efterfrågans-baserad strategi. Integrering av en storskalig batterianläggning för ett energisystem p en ö simulerades och resultaten visar en lägre nivå av slösad elkraft. I både fallen används projicerade kostnader för att utvärdera den tekno-ekonomiska presentandan.

Fastoxid elektrolysörer (SOFC) inom ramen av elkraft-till-gas uppgradering av biogas omfattar det andra energilagringssätt som studerades. Uppgraderingsprocessens mål var att öka metanhalten hos biogasen med direktomvandling av koldioxid genom högtemperatur-elektrolys och -metanisering Denna process visade verkningsgrader för energiomvandling högre än 80%. Däremot är den ekonomiska konkurrenskraften en funktion av elkostnaden, kostnaderna hos de olika komponenterna och gaskostnaden.

Abstract [pt]

A necessidade de integrar o rápido crescimento dos recursos renováveis no setor da geração da energia elétrica exige soluções capazes de mitigar a intermitência destes recursos. As energias renováveis têm o potencial para se tornar a espinha dorsal da produção elétrica nos próximos anos para alcançar os objetivos ambiciosos que dizem respeito à segurança energética e à reducão do impacte ambiental. O armazenamento da energia parece uma solução promissora para melhorar a capacidade das renováveis variáveis (eólica e fotovoltaico) de satisfazerem continuamente a procura de energia elétrica, principalmente através da disponibilização do excesso de energia gerada.

Entre as diferentes opções que podem favorecer a integração dos recursos renováveis intermitentes, as tecnologias para o armazenamento eletroquímico – baterias e células de electrólise – constituem o foco desta tese. Estas abordagens permitem adiar o uso de grandes quantidades de energia a médio-longo prazo, são independentes da localização e são, além do mais, consideradas uma componente estratégica do plano para a descarbonização na União Europeia – a entidade geo-política sobre a qual o trabalho se concentra.

Os sistemas de armazenamento com baterias são analisados para casos de estudo de pequena e grande escala para quantificar os beneficios energético e económico que derivam de um uso mais eficiente dos recursos renovaveis. Para a pequena escala apresenta-se a análise de um sistema de baterias conectado a um sistema fotovoltaico residencial e os resultados são comparados a uma estratégia de demand response para o deslocamento da carga. Para a larga escala, simula-se a integração de uma instalação de baterias no sistema de energia de uma ilha e os resultados mostram um nível muito menor de curtailments de energia renovável. Em ambas as situações, usaram-se os custos projetados das tecnologias para avaliar o seu desempenho técnico-económico.

As células de eletrólise de óxido sólido (Solid Oxide Electrolysis Cells – SOECs) foram analisadas para um processo power-to-gas mediante o upgrading de biogás. Esta tecnologia constitui o segundo tipo de armazenamento eletroquímico de energia que foi estudado. O processo de upgrading serve para aumentar o conteúdo de metano no biogás, convertendo diretamente o dióxido de carbono contido nele, por meio de eletrólise a alta temperatura e metanação. A eficiência de conversão de energia deste processo mostrou-se superior a 80%. Contudo, a viabilidade económica deste conceito depende maioritariamente do custo da eletricidade, do custo dos componentes principais e do preço do gás natural.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2018. , p. 114
Series
TRITA-ITM-AVL ; 2018:43
Keywords [en]
Electrical Energy Storage, Battery Energy Storage, Lithium-ion Batteries, Vanadium Flow Batteries, Power-to-Gas, Electrolysis, Biogas Upgrading
Keywords [pt]
Armazenamento de Energia Elétrica, Armazenamento de Energia em Baterias, Baterias de Iões de Lítio, Baterias de Fluxo de Vanádio, Power-to-Gas, Eletrólise, Upgrading de Biogás
Keywords [sv]
Elenergilagring, batterilagring, litiumjonbatterier, vanadinflödesbatterier, elkraft-till-gas, elektrolys, biogasuppgradering
National Category
Engineering and Technology Energy Engineering Chemical Engineering
Research subject
Energy Technology
Identifiers
URN: urn:nbn:se:kth:diva-234822ISBN: 978-91-7729-940-0 (print)OAI: oai:DiVA.org:kth-234822DiVA, id: diva2:1247170
Public defence
2018-10-08, Kollegiesalen, Brinellvägen 8, Stockholm, 10:00 (English)
Opponent
Supervisors
Projects
SELECT+
Note

QC 20180912

Available from: 2018-09-12 Created: 2018-09-11 Last updated: 2018-09-12Bibliographically approved
List of papers
1. Techno-economic comparison of storage vs. demand response strategies in distributed generation systems
Open this publication in new window or tab >>Techno-economic comparison of storage vs. demand response strategies in distributed generation systems
2015 (English)In: 2015 12th International Conference on the European Energy Market (EEM), IEEE, 2015Conference paper, Published paper (Refereed)
Abstract [en]

This paper investigates the benefits in terms of energy use and cost reduction of electricity storage using batteries and the implementation of demand response strategies, to mitigate the mismatch between the renewable production and the demand in smart grids. A comparison between the two approaches in a household with micro-generation system is made in order to assess which one is the most feasible for small scale users. The results show that in general the use of demand response has more benefits to the end-user.

Place, publisher, year, edition, pages
IEEE, 2015
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-234677 (URN)10.1109/EEM.2015.7216725 (DOI)2-s2.0-84951976466 (Scopus ID)978-1-4673-6692-2 (ISBN)
Conference
12th International Conference on European Energy Markets, Lisbon, May 20-22, 2015
Note

QC 20180910

Available from: 2018-09-07 Created: 2018-09-07 Last updated: 2018-09-11Bibliographically approved
2. Comparing demand response and battery storage to optimize self-consumption in PV systems
Open this publication in new window or tab >>Comparing demand response and battery storage to optimize self-consumption in PV systems
2016 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 180, p. 524-535Article in journal (Refereed) Published
Abstract [en]

The paper examines and compares the potential of storage in batteries versus demand response strategies for electricity bill reduction in the residential sector, in the context of the new trend of installing PV systems for self-consumption. The performances of the two methodologies are investigated by applying them to the data of a real household which owns a small solar photovoltaic installation. The benefits of storage and demand response are evaluated through an optimization analysis with a linear programming algorithm. The simulations are carried out both for real market prices of the equipment and for reduced ones, to simulate the case of strong technological development and the corresponding price decrease in the coming years. The electricity pricing scheme is a dual tariff regime modeled according to the Portuguese current rules. The results suggest that at the moment, demand response should be preferred with the current market prices of the hardware. However, a significant decrease in the batteries price can make storage an interesting alternative, especially for the cases in which demand response is not easily applicable.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Self-consumption, Linear programming, Demand response, Battery storage, PV integration
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-193791 (URN)10.1016/j.apenergy.2016.07.103 (DOI)000383291900044 ()2-s2.0-84989899351 (Scopus ID)
Note

QC 20161024

Available from: 2016-10-24 Created: 2016-10-11 Last updated: 2018-09-11Bibliographically approved
3. Techno-economic analysis of utility-scale energy storage in island settings
Open this publication in new window or tab >>Techno-economic analysis of utility-scale energy storage in island settings
(English)In: Journal of Energy Storage, E-ISSN 2352-152XArticle in journal (Other (popular science, discussion, etc.)) Submitted
Abstract [en]

The decarbonization of the electricity supply in isolated and remote energy systems is an open challenge in the transition to a sustainable energy system. In this paper, the possibility to increase the penetration of renewable energy sources for electricity generationon the island of Terceira (Azores) is investigated through the installation of a utility-scale energy storage facility. The electric power dispatch on the island is simulated through a unit commitment model of the fossil and renewable power plants that has the objective of minimizing the cost of electricity generation. Battery energy storage is employed to partially decouple production and supply, and to provide spinning reserve in case of sudden generator outage. Two technological options, namely lithium-ion and vanadium flow batteries, are compared in terms of net present value and return on investment, with the aim of supporting the decision-making process of the local utility. The economic evaluation takes also into account the degradation of the battery performance along the years. The results, obtained in a future-price scenario, show that both the technologies entail a positive investment performance. However, vanadium flow batteries have the best results, given that they produce a net present value of up to 242% of the initial capital invested after 20 years, with a return on investment higher than 20%. In this scenario, the renewable share can reachup to 46%, compared to the current 26%.

National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-234682 (URN)
Note

QC 20180910

Available from: 2018-09-07 Created: 2018-09-07 Last updated: 2018-09-11Bibliographically approved
4. Digester Gas Upgrading to Synthetic Natural Gas in Solid OxideElectrolysis Cells
Open this publication in new window or tab >>Digester Gas Upgrading to Synthetic Natural Gas in Solid OxideElectrolysis Cells
2015 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 29, no 3, p. 1641-1652Article in journal (Refereed) Published
Abstract [en]

This work focuses on the process design and performance of an innovative plant for digester gas upgrading tosynthetic natural gas (SNG). The differences and advantages over traditional upgrading processes are discussed. The mainstrength of digester gas upgrading via high-temperature electrolysis concerns its higher synthetic natural gas productivity for agiven raw digester gas feed. Electrolysis is performed through a solid oxide electrolysis cell (SOEC) system, which is fed withdemineralized water and purified digester gas (made up of methane and carbon dioxide). Surplus electricity from intermittentrenewable energy sources is used to supply the energy required for the SOEC stacks. The resulting methane-rich syngas isreacted in a series of methanators to yield a high CH4 content output stream. The steam reforming reaction is promoted bymeans of a nickel catalyst in the cathode (fuel) electrode, which reduces the methane fraction: hence, sulfur, which is present inseveral types of digester gas (e.g., from sewage or landfills) in the form of hydrogen sulfide, has been identified as a possibleinhibitor for this reaction. However, it is also well-known that sulfur is responsible for the deterioration of the electrochemicalperformance of a stack. Therefore, its effect on the system has been modeled for different thermodynamic conditions. This studyanalyses the electrochemical and energy performance of the integrated process through which all the carbon contained in digestergas is converted/upgraded to methane-rich gas. The electrochemical dissociation of the CO2 contained in the digester gas to CH4(with the addition of external demineralized water) is one way of cleverly exploiting the carbon content in digester gas when poorquality or limited biological substrates are available for anaerobic digestion. Finally, a comparison with other commercial digestergas upgrading techniques has been made.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2015
Keywords
Biogas upgrading, co-electrolysis, sulfur passivation
National Category
Energy Systems
Research subject
Chemical Engineering; Energy Technology
Identifiers
urn:nbn:se:kth:diva-234681 (URN)10.1021/ef5023779 (DOI)000351653200037 ()2-s2.0-84925115472 (Scopus ID)
Note

QC 20180910

Available from: 2018-09-07 Created: 2018-09-07 Last updated: 2018-09-11Bibliographically approved
5. Exergo-economic analysis of a direct biogas upgrading process to synthetic natural gas via integrated high-temperature electrolysis and methanation
Open this publication in new window or tab >>Exergo-economic analysis of a direct biogas upgrading process to synthetic natural gas via integrated high-temperature electrolysis and methanation
2017 (English)In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 141, p. 1524-1537Article in journal (Refereed) Published
Abstract [en]

Biogas upgrading to synthetic natural gas (SNG) is a viable and appealing route for power-to-gas because it combines waste management with the use of the surplus electricity that might arise in energy systems having a considerable share of renewable energy sources in their production mix. In this work, the exergo-economic performance of a biogas upgrading process through integrated electrolysis and methanation is assessed in connection with the current market status to test which conditions could make the proposed option economically viable. Two different configurations, which differ mainly for the operating pressure of the electrolyser, are compared. The exergy efficiencies are high (>80%) and exergo-economic costs of the produced bio-SNG in the two analyzed configurations are 5.62 and 4.87 c(sic)/kWh(exergy), for low- and high-pressure respectively. Lower values would be required for the bio-SNG to compete with fossil natural gas. We show how both the input electricity price and the capacity factor have a substantial impact on the economic sustainability of the process. Eventually, the monetary exploitation of the oxygen produced by electrolysis and the participation to the emission trading scheme could contribute further to improve the economic attractiveness of the process.

Place, publisher, year, edition, pages
Elsevier, 2017
Keywords
Power-to-gas, Biogas upgrading, SOEC, Exergo-economic analysis, Carbon capture and usage (CCU)
National Category
Energy Systems
Identifiers
urn:nbn:se:kth:diva-222456 (URN)10.1016/j.energy.2017.11.080 (DOI)000423249200015 ()2-s2.0-85034747846 (Scopus ID)
Note

QC 20180209

Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2018-09-12Bibliographically approved

Open Access in DiVA

PhD Dissertation Guido Lorenzi(1917 kB)689 downloads
File information
File name FULLTEXT02.pdfFile size 1917 kBChecksum SHA-512
c5d4a4dd6d25e308ba48e3ea477f698576efa9a4f8a63fb4a70d05d55c2ac7448dff8fe209b928ff2b8d326d5708637a6b028bf6cecb84825881185a9daef01c
Type fulltextMimetype application/pdf

Authority records BETA

Lorenzi, Guido

Search in DiVA

By author/editor
Lorenzi, Guido
By organisation
Heat and Power Technology
Engineering and TechnologyEnergy EngineeringChemical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 689 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 460 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf