Editorial: Energy storage

Abstract

Finding ways to implement the cost-effective storage of electrical energy has been an objective of power system planners and operators since the beginning of public electricity supply more than 100 years ago. Indeed, some of the very early direct current municipal supply systems used large flooded batteries to feed lighting systems through the night. More recently, a small number of large pumped hydro schemes have provided specialist services such as frequency response. There have also been demonstration projects of other storage technologies such as compressed air energy storage and flywheels, but these have not led to widespread deployment. The low-carbon power systems now being developed in response to climate change offer greatly increased opportunities for electrical energy storage systems to assist in balancing supply and demand as well as supplying a whole range of ancillary services. However, the commercial case for energy storage in large power systems has yet to be demonstrated clearly and its use is presently restricted to niche markets. The convenience and low price of fossil fuel, which is really energy stored in chemical form, have been too great to allow energy storage systems to be developed and used widely. This is now changing and the number and type of energy storage systems is rising rapidly. The increasing importance of energy storage and how it can be implemented led to this themed issue and it was encouraging to receive such a strong set of papers. Our briefing note is by Price (2015), addressing the allimportant regulatory issues. Without regulation that rewards its value to the power system fairly, a sustainable business case for energy storage cannot be made. The briefing addresses the particular issues for energy storage within the UK and makes comparison with other countries. The present regulatory structure in the UK does not allow easy access to all the various multiple revenue streams that are likely to be required for a commercial case to be constructed for energy storage and so stimulate its use.