Editing Pieee (section)

===Thermal storage===

====Concept and development of a pumped heat electricity storage system====
*'''Authors:''' Jonathan Howes (Isentropic Ltd, United Kingdom) 
*'''Contact email:''' jonathan.howes@isentropic.co.uk
*'''Scope:''' The paper will first address (a) the early conceptualization of a system for heat/work conversion based upon the first Ericsson cycle of 1833 in combination with massive thermal storage in gravel and (b) the development and test of the first prototype. Using these test results, mathematical modeling of the engine/heat pump and thermal stores has yielded improved second and third prototypes. Design of the second prototype and its behavior under test will be discussed.  Extant test results will be employed to extrapolate to the predicted performance of massive utility-scale equipment.
 
====Molten salt power towers—New players in commercial energy storage====
*'''Authors:''' Rebecca Dunn (Australian National University, Australia), Matthew Wright (Beyond Zero Emissions, Australia), Patrick Hearps (University of Melbourne, Australia) 
*'''Contact email:''' rebecca.dunn@anu.edu.au
*'''Scope:''' Concentrating solar power (CSP) can both generate and store renewable energy all in the one plant. Curved mirrors concentrate the sun’s energy to be stored as heat, for example in a mixture of molten salt, or in a chemical reaction. When required, this stored energy can be used to produce steam and drive a turbine. In this way, variable renewable energy sources such as wind and photovoltaics can be dispatched to the grid first, and the “back-up” provided by concentrating solar plants with storage.  CSP trough plants with 7.5 hours of molten salt storage have been operating in Spain since 2008. But there is a new player in the CSP storage market—the solar power tower with molten salt storage. Towers can achieve higher temperatures than troughs—565<sup>o</sup>C as opposed to 380<sup>o</sup>C—and hence store more megawatt-hours of energy in the same amount of salt.  In March 2011, Torresol Energy of Spain will commission the 17 MWe Gemasolar power tower with 15h of molten salt storage. At the same time, US firm SolarReserve will be constructing a 50 MWe plant in Spain, and a 100 MWe plant in Nevada—both with around 15h of molten salt storage. Near-term advances include using oxygen blankets to allow higher storage temperatures up to 650<sup>o</sup>C, and the use of quartz fillers and thermocline tanks to reduce the quantity of salt required.

====Concentrating solar thermal with storage using calcium hydride for low cost dispatchable energy====
*'''Authors:'''  David Harries (EMCSolar, Australia), Wayne Bliesner (EMCSolar, Australia), John Davidson (EMCSolar, Australia)
*'''Contact email:''' john.davidson@emcsolar.com.au
*'''Scope:''' The energy storage technology being developed is a thermochemical energy heat storage system that uses solar radiation to drive highly endothermic chemical dissociation reactions.  The heat is recovered in a highly exothermic reformation reaction. The system has a significantly higher energy storage density than do conventional solar energy storage systems. It also operates at high temperature, which increase the thermodynamic and solar energy to electricity system efficiency. The thermochemical energy storage system being developed in this project is based on the dissociation of calcium hydride (CaH<sub>2</sub>).  As calcium hydride is heated it absorbs solar energy to drive the endothermic dissociation reaction at around 1000<sup>o</sup>C. Operating at this high temperature increases the reaction rates and the overall system efficiency.  As hydrogen gas is released, it is removed and stored in low temperature hydride storage vessels, a low cost bulk hydrogen storage technique, the calcium remains in the reactor vessel. When solar radiation levels fall, or the amount of electricity required increases (peak electricity demand periods), hydrogen is returned to reaction vessel and an exothermic reformation (fusion) reaction releases heat. All of the materials used, including calcium, hydrogen, sodium and aluminum are available in quantities that make it possible for large numbers (Gigawatts) of the solar energy storage plant to be built over the next 15 years.

==== Review of massive solar thermal storage techniques and the associated heat transfer technologies that undergird them====
*'''Authors:''' Luisa F. Cabeza (Universitat de Lleida, Spain), Cristian Solé (Universitat de Lleida, Spain), Albert Castell (Universitat de Lleida, Spain), Eduard Oró (Universitat de Lleida, Spain), Antoni Gil (Universitat de Lleida, Spain).
*'''Contact email:''' lcabeza@diei.udl.cat
*'''Scope:''' Thermal energy storage is a key component of solar power plants if dispatchability is required. On the other hand, although different systems and many materials are available, only a few plants in the world have tested thermal energy storage systems. Here, all materials considered in literature and/or used in real plants are tested, the different systems are described and analyzed, and real experiences are compiled. The associated heat transfer technologies to support and improve these systems are described and analyzed.
 
====High temperature solid media thermal energy storage for solar thermal power plants====
*'''Authors:''' Doerte Laing (German Aerospace Center, Germany)
*'''Contact email:''' Doerte.Laing@dlr.de
*'''Scope:''' The paper will give an overview of the development of high temperature thermal energy storage using concrete as a storage medium. It will summarize the material characteristics, construction and long term testing of a 20 m<sup>3</sup> test module and performance evaluation for a full year simulation, integrated in a parabolic trough power plant.