Mexico is the most energy secure country among the 25 largeest energy users, according to a groundbreaking new report by the U.S. Chamber’s Institute for 21^st Century Energy (Energy Institute).

Bolstered by its strong scores on fossil fuel imports, energy expenditures and per capita energy usage, Mexico topped the inaugural edition of Institute’s International Index of Energy Security Risk. The United States ranks seventh, largely due to improvements in extraction technologies and the subsequent growth in shale oil and gas production. The lowest score belongs to Ukraine, which spends much more on fossil fuel imports than average.

“The purpose of the Index is to help make sense of the significant transitions occurring in world energy markets and how the U.S. and other major energy users are coping with the energy security implications of these transitions,” said Energy Institute President and CEO Karen Harbert at an October 15 event to release the Index.

The study examined 28 metrics including fossil-fuel imports, power generation and carbon-dioxide emissions, primarily using data from the U.S. EIA and the Paris-based International Energy Administration. The report provides a detailed look at energy security from 1980 to 2010 for 25 developed and emerging economies.

While Mexico ranks highest in security, that position could very well slip in the next few years, according to Harbert. “Mexico is now turning the curve,” Harbert said. “Oil production is going down in Mexico and their transportation use is going way up.”

The U.S., however, could see its ranking rise on the index, according to energy experts attending the Index unveiling. The Department of Energy’s Adam Sieminski, administrator with the Energy Information Administration said that the U.S. may exceed government estimates and become a net exporter of natural gas by the end of this decade. The “growth in shale gas and tight oil has made an unbelievable difference to energy security in the U.S.,” he said. “This looks like a pattern that is set to continue.”

The Energy Institute will look more closely at U.S. energy security when it releases its’ updated U.S. Energy Security Risk Index on October 24. The U.S. Index, which is updated annually, tracks changes in energy security risk beginning in 1970 and projects future risk through 2035. That index assesses a score based on four major areas of risk to U.S. energy security —geopolitical, economic, reliability, and environmental—against 37 factors of supply, end-use, operations, and environmental performance.

To use the interactive web tool to the International Index, including risk index scores for an additional 50 countries, go to www.energyxxi.org/energysecurity