Every winter, one of the most actively discussed issues of energy policy - both on TV and in professional circles - is natural gas. Prices and supply conditions are frequently part of the political debate. The main reason behind such active discussion is energy security concerns. What is energy security? The International Energy Agency defines energy security as “the uninterrupted availability of energy sources at an affordable price.” Obviously, all countries around the world care about energy security, because interruptions in the availability of energ...