Over the next 15 years, the United States will require significantly more raw fuel for primary energy, according to Bill Bowen, Ph.D., a professor at 91������Ʒ’s Maxine Goodman Levin College of Urban Affairs.

For more than 30 years, his research has examined energy policy, economic development and environmental affairs. Recently, Dr. Bowen has studied future energy consumption.

“My main assumption has been simply that the rates of change we have witnessed over the past 40 years, in terms of U.S. population and energy consumption, will continue,” he said.

According to the Energy Information Administration, U.S. energy consumption over the past four decades has increased from 74 quadrillion BTUs, or quads, to 97.5 quads. We’ve trended toward consuming less energy per person, but this has been offset by the increasing number of people. On average, each new person added to the population during this period increased our annual energy consumption by about 284.5 million BTUs of primary energy.

The Census Bureau projects the U.S. population will grow to somewhere between 353 million and 364 million in 2030.

“Putting these numbers together, we can predict that the United States will need between 10 and 12.8 additional quads of energy, per year, by 2030,” Dr. Bowen said. “Assuming our energy consumption per capita stays about the same, we’re talking about an additional equivalent between 1.9 billion and 2.4 billion barrels of gasoline or between 500 million and 641 million tons of coal.”

For more on Dr. Bowen’s research, check out .