1. B. Kirby (2007) Ancillary Services: Technical and Commercial Insights, Wartsila North America Inc. http://web.ornl.gov/sci/ees/etsd/pes/publications.shtml.
2. North America Electric Reliability Corporation, Balancing and Frequency Control (2011), http://www.nerc.com/docs/oc/rs/NERC%20Balancing%20and%20Frequency%20Control%20040520111.pdf.
3. H.F. Illian (2010) Frequency Control Performance Measurement and Requirement, Tech. Report LBNL-4145E, Lawrence Berkeley National Laboratory, https://eta-publications.lbl. gov/sites/default/files/lbnl-4145e.pdf.
4. The role of energy storage in development of smart grids;Roberts;Proc. IEEE,2011
5. California Energy Storage Alliance (CEA) (2011) Energy Storage — A Cheaper, Faster and Cleaner Alternative to Conventional Frequency Regulation. http://files.energystorageforum. com/CESA_FR_White_Paper_2011-02-16.pdf.