The article focuses on energy security and its application in the United States. Considering the latest development in the field of domestic natural gas production, the use of energy sources in the USA shall undergo a substantial change. To track the change, the paper is divided into two sections. Firstly, the paper compares current definitions of energy security adopted by International Energy Agency (IEA), Energy Information Administration (EIA) and American Security Project (ASP) and brings forth the theoretical background. It also identifies the difference between energy security and energy independence from the American point of view. Secondly, it examines the influence of domestic production of natural gas, namely the importance of natural gas in the US energy mix, its role in diversifying of energy sources portfolio and its projected development in the future. This section develops practical application of the above stated theoretical point of view. Methods used in the paper clearly correspond with its orientation and sources. Comparative analysis will be used in order to examine differences between the definitions and their application. As they are mainly of the US origin, the results are very similar to all of them. The emphasized characteristics of energy security are flexibility, competition and redundancy. Then, analysis is used to track the changing position of natural gas and its role in securing energy abundance. There are two possible scenarios implying from the analysis. First, natural gas shall build a basis for commodity export and will lead to increase in price of domestic production due to interconnection of global market. Second, domestic gas shall serve as substitution of import and hence result in greater domestic supply. The main conclusions are two. First, energy security and energy independence are two terms having a lot in common, but must not be confused as one. Energy independence in the sense of all energy used coming from within the country without international trade is not possible and even not desirable in a world so interconnected and globalized. Domestic commodity pricing is highly dependent on global market and can be a source of fluctuation despite full insulation from import. The main aim of energy security is thus not to cut the country off from the international commodity market, but to ensure enough energy for reasonable price. It comes together with flexible domestic market, free and unspoiled competition and redundancy. Its task is also to ease the way of switching between the fuels to guarantee long term sustainable energy supply protecting from supply shocks. Second, the development of domestic natural gas production of the latter years shows its growing importance as an alternative fuel to oil. However, as its use in transportation is still very low, it is probably not to decrease the US vulnerability to oil price change. On the other hand, underground storage facilities provide a good cushion for temporary supply disruption. The level of storage around 30% of domestic annual consumption suggests that the gas market is able to absorb those fluctuations. Moreover, increasing domestic production creates pressure on either export of natural in the form of liquefied natural gas (LNG) or on replacing import for domestic production. The main issue of LNG export lies in currently underdeveloped liquefying and export facilities in the USA together with considerably high bureaucracy connected to allowance to export. It could also influence the price development in the future as long as the cost of transport will not allow for complete connectedness of the export markets, mainly European and Japanese, the price in the USA shall remain lower than in those two regions. The more probable scenario is thus currently replacing exported gas with domestic production.
