Pumped hydro energy storage schemes to support high RES penetration in the electric power system of Greece

According to Directive 2009/28/EC on the promotion of the use of energy from renewable sources, for Greece the target of RES penetration into gross final energy consumption in 2020 is set at 18%. The contribution of RES to energy consumption in Greece during the period 2006-2016 showed a significant increase. More specifically, the total contribution of RES as a share of gross final energy consumption in the year 2016 was 15.2%, more than doubling the relative share corresponding to RES in 2006. Similarly, the share of electricity from RES to gross electricity consumption in the year 2016 stood at 23.8%. In the National Energy and Climate Plan (NECP) prepared and submitted to the European Commission in January 2019 on the basis of Regulation EU) 2018/1999 on the governance of the Energy Union and Climate Action and Directive (EU) 2018/2001 on the promotion of the use of energy from renewable sources, a target for the RES share in the gross final energy consumption in 2030 is set at 31%and respectively a target for the RES share in the gross final electricity consumption is set at 55%. More specifically, to achieve the above target in the electricity sector, it is estimated that more than 9GW of variable wind and photovoltaic (PV) plants must be installed. To reach such high levels of such RES penetration into the gross final electricity consumption, energy storage needs arise. For several decades, Pumped Hydro Energy Storage (PHES) is the most widespread international format for large-scale storage of electricity. This paper attempts to provide an overview of the status and prospects of PHES in Greece. It also tries to identify obstacles in installing and operating PHES in Greece using experience from other countries.