Papers cited in web notes or used in their preparation:

Grid Energy Storage, U.S. Department of Energy, December 2013 (link / cached copy)

Analysis of Hydrogen and Competing Technologies for Utility-Scale Energy Storage, U.S. National Renewable Energy Lab (link / cached copy)

National Assessment of Energy Storage for Grid Balancing and Arbitrage, U.S. Department of Energy (link / cached copy)

Electricity Storage, SBC Energy Institute 2013 (link / cached copy)

Energy Storage Technology Review, Kyle Bradbury (link / cached copy)

Energy Storage Technologies for Electric Applications, Martin (link / cached copy)

Projections of Levelized Cost Benefit of Grid-Scale Energy Storage Options, Doty Energy 2010 (link / cached copy)

Pumped Storage Hydro:

Pumped-Hydro Energy Storage: Potential for Transformation from Single Dams, Strategic Energy Technologies Information System (SETIC), European Commission, 2012 (link / cached copy)

Quantifying the Operational Benefits of Conventional and Advanced Pumped Storage Hydro on Reliability and Efficiency, U.S. National Renewable Energy Lab, 2013 (link / cached copy)

Hydrogen Storage:

Analysis of Hydrogen and Competing Technologies for Utility-Scale Energy Storage, U.S. National Renewable Energy Lab (link / cached copy)

Hydrogen for Energy Storage Analysis Overview, U.S. National Renewable Energy Lab 2010 (link / cached copy)

Flywheel Storage:

Flywheel Energy Storage, Wikipedia (link / cached copy)

Beacon Power 20 MW Flywheel Frequency Regulation Plant, U.S. Department of Energy - 2013 (link / cached copy)

New Energy Storage Plant Could 'Revolutionise' Renewable Sector, The Guardian 2015 (link / cached copy)

High-tech Renewable Energy Storage 'Wheel' to be built in Offaly, RTE News 2015 (link / cached copy)

Compressed Air Energy Storage (CAES):

Revived Energy Storage Technology Offers Major Grid Benefits, Power Magazine 2008 (link / cached copy)

Compressed Air Energy Storage: Theory, Resources, And Applications For Wind Power, Succar & Williams, Princeton University 2008 (link / cached copy)

Design and Evaluation of an Advanced Adiabatic Compressed Air Storage System at the Michigan-Utah Mine, Beeman, University of Utah 2010 (link / cached copy)

Modeling of an Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) Unit and an Optimal Model-based Operation Strategy for its Integration into Power Markets, Steta, ETH - Zurich 2010 (link / cached copy)

ADELE – Adiabatic Compressed-Air Energy Storage for Electricity Supply (link / cached copy)

Electricity Storage with Adiabatic Compressed Air Energy Storage: Results of the BMWi-project ADELE-ING, Zunft et al., International ETG Congress 2017 (link)

Overview of Compressed Air Energy Storage and Technology Development, Wang et al., Energies 10, p. 991 (2017) (link / cached copy)

Super Capacitor Storage:

Fabrication of Large Area hexagonal Boron Nitride Thin Films for Bendable Capacitors, Wei, Nano Research 2013 (link)

Super Batteries:

Electrochemical Energy Storage for Green Grid, Yang, Chemical Reviews 2011 (link)

Energy Storage Technologies for Electric Applications, Martin (link / cached copy)

Molten Salt Storage:

Advanced Thermal Storage System with Novel Molten Salt, U.S. National Renewable Energy Lab 2013 (link / cached copy)

Research Continues on Solar with Molten Salt Storage, Renewable Energy World, 2015 (link / cached copy)