Science
7:05 am
Thu October 25, 2012

Algae As Car Fuel: Possible, But Not Sustainable?

Transcript

RENEE MONTAGNE, HOST:

Let's take a look at alternative energy now. There's growing interest and investment in the process of extracting oil from algae and turning it into fuel for vehicles and airplanes. It requires a lot of water, nutrients and land. And a new report from the National Research Council says that will make it challenging to turn algae into a sustainable source of energy.

NPR's Richard Harris reports.

RICHARD HARRIS, BYLINE: The U.S. Department of Energy has been funding research on algae-based fuels on and off since the late 1970s. And a budding industry is now starting to grow large quantities of algae in sunny, open ponds to make biofuel. So the DOE recently turned to the National Academy of Sciences Research Council to ask whether algae could be a sustainable energy source if it goes big-time.

Jennie Hunter-Cevera chaired the committee that took on that task. She says simply defining sustainable in this context is a challenge.

JENNIE HUNTER-CEVERA: You can look at the amount of energy going into it. You can look at the water needed, the nutrients - CO2, phosphorous, nitrate - as well as other things that could impact the environment.

MARK JONES: And what we came back and said was, yes, there are challenges.

HARRIS: Mark Jones from Dow Chemical served on the panel.

JONES: We are not currently line of sight to a solution with algal biofuels. But there is nothing that is insurmountable in the challenges that exist.

HARRIS: Jones says, for example, the committee asked how much energy it takes to make these fuels. Obviously you don't want to consume more energy than you're going to get back in the form of fuel.

JONES: You have a fair bit of energy that is required to actually just cultivate the algae to keep them suspended and moving in the water. You have a fair bit of energy in removing the algae from the water itself in that collection. And then you have the processing energy of breaking the algae open to get the oils out.

HARRIS: And it takes a bit more energy to turn the oils into fuel. And then there's land. An acre of algae ponds would produce enough fuel to supply maybe 10 cars.

JONES: When you map that out and start talking about making a refinery's worth of fuel, you have huge tracks of land that would be devoted to algae. This is not something that everybody is going to grow algae in their backyard and be able to fill their fuel needs.

HARRIS: A big challenge.

Tim Zenk, at Sapphire Energy in San Diego, says his algae energy company, and in fact the whole industry has been thinking hard about ways to avoid these pitfalls. His company is building a big facility out in New Mexico, using groundwater that's too salty for agriculture.

TIM ZENK: The land that we are using by design is land that has been out of agricultural production for 40 years because of salt water groundwater intrusion. So for the last 40 years the farmer that owned the land hasn't had the ability to actually farm those acres.

HARRIS: And his company thinks carefully about how much energy it uses. But these are early days, with companies like Sapphire Energy finding ideal settings, like this abandoned farmland in New Mexico. The real challenges would come if the industry multiplied a thousand-fold to produce a significant share of our liquid fuels. Zenk says that's decades down the road.

ZENK: We can only hope to be such a successful company that we are - produce a billion gallons into the renewable fuel pool.

HARRIS: The academy committee's chair, Jennie Hunter-Cevera, says the challenges are big but not overwhelming.

HUNTER-CEVERA: If you look where they started to where they are today, it's pretty impressive in what they have achieved. I think this industry has a lot of potential.

HARRIS: But Hunter-Cevera says this is a good time to pause and ask a question that isn't asked often enough, and that is: Will this new industry actually live up to its promise of making the world a better place as it displaces fossil fuels?

Richard Harris, NPR News. Transcript provided by NPR, Copyright NPR.