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Location: Louisville
Growth (1999-2003): 2,094%
2003 Revenue: $6.5 million
Employees: 47
During the big blackout of 2003, all eyes were on Genscape. The company monitors the status of power plants across the country and sells the data to regulators, traders, and distributors. When the lights went out, it was one of the few companies that could offer an up-to-the-minute picture of the nation's power grid, and CEO Sean O'Leary says he spent three days on the phone with government officials.