Shale gas supply scenarios To determine potential shale gas production for its scenarios, ENTSOG has taken into consideration a range of data including information from Pöyry and TSO esti- mates. Due to the uncertainty around the development of shale gas on EU territory, the below scenarios are only taken into account in the High Infrastructure Scenario. \\ Maximum shale gas scenario Given the uncertainty surrounding EU shale gas production, this scenario is based on the conservative “Some Shale Gas” estimate included within Pöyry’s 2013 report. It includes the application of environmental and planning constraints (limiting the number of possible drilling areas because of environ- mental and planning concerns) as well as constraints regarding practical (drill- ing rig trained staff availability) and financial (cost of production exceeding pos- sible future market prices) issues. \\ Intermediate shale gas scenario This scenario is based on the data from TSOs estimates of shale gas produc- tion, collected by ENTSOG in July 2014. It should be noted that several TSOs have not been able to provide data on shale gas production in their countries. In such case no production has been included. \\ Minimum shale gas scenario This scenario is based on no shale gas being developed in Europe in the upcoming years due to the high uncertainty. This implication is based on the current weak results of shale gas extraction in Europe, difficult geological formations, the lack of available trained staff and technologies in Europe, and also public and governmental opposition due to the risks associated to the extraction technics.