Through efficiency and flexibility, significant portions of the current infrastructure can be repurposed for greener energy sources; that was the tentative consensus of a panel discussion earlier this week at the Milken Institute Global Conference.

The question put to the panel, titled Repurposing Energy Infrastructure, by Milken Institute Senior Fellow Joel Kurtzman was this:

Over the last 120 years, the world has invested something on the order of $100 trillion in the current energy infrastructure. Is there a way that we can move toward more desirable energy sources and a more secure energy system through repurposing some of this tremendous infrastructure rather than abandoning it?

The answer to the question had better be yes because $100 trillion is hard to find these days.

POET Chairman and CEO Jeff Broin pointed out that we’ve been repurposing gasoline infrastructure for ethanol in the U.S. for a couple of decades so that today, ethanol makes up ten percent of the U.S. gasoline supply. Moving forward, Broin said it will be important for the infrastructure to remain flexible because gasoline will be around for a long time. That can best be accomplished through flex pumps and flex fuel vehicles that would allow ethanol to gradually replace more gasoline with only moderate changes to the current infrastructure.

The perspectives of “drop-in fuels” and electric vehicles were also represented on the panel. Dr. Frances Arnold, a co-founder of Gevo, talked about the expected advantages of drop-in fuels like butanol if they can reach commercial scale. Steven (Mac) Heller, executive chairman of electric car and battery company CODA Automotive, said that the existing electrical infrastructure is fuel flexible and largely domestic, but that the big challenge will be getting large numbers of electric vehicles on the road.

Also participating was Karen Alderman Harbert, President and CEO of the Institute for 21st Century Energy at the U.S. Chamber of Commerce. Harbert, who referred to herself as the “token policy wonk,” said that the days of big energy subsidies are coming to an end because of the government’s budget woes. One concept the U.S. Chamber is supporting is a Clean Energy Development Administration (CEDA) that would help develop clean energy technologies.

Kurtzman asked provactively whether or not the government should even have an energy policy. The panel generally agreed that government must play a role in speeding up the adoption of promising technologies and providing a stable climate for investors and developers. Broin said that stable policy and incentives for infrastructure were important areas where government could contribute.

There are certainly challenges to repurposing energy infrastructure, but the panel was largely optimistic about achieving some degree of success. As Dr. Arnold said: “The answer to the question had better be yes because $100 trillion is hard to find these days.”

Nathan Schock is Director of Public Relations for POET, a fully integrated ethanol company that produces more than 1.7 billion gallons of ethanol per year from 27 plants in seven states. The company is also in a partnership with the U.S. Department of Energy and the State of Iowa to commercialize the production of cellulosic ethanol from corn cobs, leaves and husks. He writes on energy issues at Rhapsody in Green.