A novel electrical energy storage system based on a reversible solid oxide fuel cell coupled with metal hydrides and waste steam

Van-Tien Giap, Young Duk Lee, Young Sang Kim and Kook Young Ahn

Applied Energy, 2020, vol. 262, issue C, No S0306261920300349

Abstract: Reversible solid oxide fuel cells (RSOFCs), with high energy densities, long operating times, and intermediate power ratings, have become promising devices for renewable energy storage. A metal hydride (MH) tank is a prospective thermochemical heat and hydrogen storage unit. External heat source such as waste steam is a well-known efficiency booster for high temperature electrolysis system. Here, we propose a novel RSOFC system coupled with MH and waste steam. The MH materials of MgH2-5 at.% V and LaNi5 were used for high-temperature MH (HTMH) case and low-temperature MH (LTMH) case calculations, respectively. We found that, In HTMH case, the H2 compression power was low, but the MH tank produced steam only during the last 29% of the total absorption time. When the MH tank produced steam, the SOEC mode efficiency increased by 19.3% points. In the SOFC mode, the MH tank stored 76% of heat released from stack, and the system efficiency was lower than stack efficiency by 6% points. The system round trip efficiencies of HTMH system and LTMH system were 45.6% and 48.1%, respectively. For a specific HTMH material, there is an optimal current density in the SOEC mode where heat from MH tank can be used completely and the external heat source is minimal. By choosing appropriate operating strategy or MH material, the high temperature MH can result in a system round-trip efficiency comparable to that of a low temperature MH combined with an external heat utilization system.

Keywords: Electrical energy storage; Reversible solid oxide fuel cell; Metal hydride; Waste heat; Off-design; Exergy round-trip efficiency (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (14)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0306261920300349
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:appene:v:262:y:2020:i:c:s0306261920300349

Ordering information: This journal article can be ordered from
http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/bibliographic
http://www.elsevier. ... 405891/bibliographic

DOI: 10.1016/j.apenergy.2020.114522

Access Statistics for this article

Applied Energy is currently edited by J. Yan

More articles in Applied Energy from Elsevier
Bibliographic data for series maintained by Catherine Liu ().