Storage - what could possibly go wrong? Philipp Grunewald Environmental Change Institute University of Oxford, South Parks Road, Oxford OX1 3QY philipp.grunewald@ouce.ox.ac.uk Abstract Electricity storage has been argued to be highly valuable to future low carbon energy systems. Challenges that remain are for technologies to reduce in cost and for appropriate market structures to be developed to ensure storage is built and operated in the best system interest. This paper focuses on the alignment between storage technologies, system needs and the priorities of system actors. Firstly, the cost developments in Li-Ion battery technology are reviewed. These are contrasted with alternative storage options and in the light of long term system needs. Secondly, this paper discusses the misalignment in operating priorities between different system actors. Based on this review, this paper argues that historic applications for storage have fostered a technology lock-in in favour of storage technologies with short storage duration, high performance and high costs. A strategic approach towards future system flexibility may therefore need to address a portfolio of technology development, market re-design and changes in to the current institutional structures. Paper submitted to BIEE conference “Innovation and Disruption: the energy sector in transition” 21-22 Spetember 2016, Oxford Keywords: Energy Policy, Energy Security, Energy Modelling, Storage, Tech- nology lock-in, Electricity markets 1