what is needed: Project outline ( 500 words) , proposal ( 800 words) and the full dissertation report( 15000 words) The advantages and disadvantages of Pumped Hydroelectric Energy Storage (PHES) and Underground Pumped Hydroelectric Energy Storage (UPHES): A comparative study The efficiency of Pumped Hydroelectric Energy Storage, a tried and tested energy storage technique, has now reached between 70 and 85 per cent. Globally, PHES installations maintain approximately 3 per cent of generating capacity. However, PHES has traditionally been restricted by geographic parameters; this dissertation considers the value of Underground Pumped Hydroelectric Energy Storage as an alternative to PHES. The study reviews the practical limitations of UPHES, including the progress made to date with this prototype concept. Finally, it offers recommendations for further advancement within the field, including issues of location and funding. Suggested initial topic reading: Connolly, D. (2010) A review of energy storage technologies: For the integration of fluctuating renewable energy. Technical report, Limerick University. Martin, G.C. (2010) 'Underground pumped hydroelectric energy storage', in, Barnes, F.S. and Levine, J.G. (eds) Large energy storage systems handbook. Boca Raton, FL: CRC Press, pp. 77-109.