1. U.S. Energy Information Administration (2016) Henry Hub natural gas spot price.
https://www.eia.gov/dnav/ng/hist/rngwhhdm.htm
. Accessed 23 July 2016
2. U.S. Energy Information Administration (2016) 2016 annual energy outlook. U.S. Department of Energy, Washington, USA
3. U.S. Energy Information Administration (2008) 2008 annual energy outlook. U.S. Department of Energy, Washington, USA
4. Eilperin (2013) EPA’s Pruitt signs proposed rule to unravel clean power plan.
https://www.washingtonpost.com/politics/epas-pruitt-signs-proposed-rule-to-unravel-clean-power-plan/2017/10/10
. Accessed 8 October 2017
5. Sisternes FJD, Jenkins JD, Botterud A (2016) The value of energy storage in decarbonizing the electricity sector. Appl Energy 175:368–379