GOLDEN, Colo. (CBS4) – In a little bottle that contains what looks like a veggie cocktail, microbiologist Nancy Dowe holds an energy future. In the solution sloshing around in the bottle is a tiny being with a talent for generating a common energy source.
Researchers at the National Renewable Energy Laboratory in Golden are so fond of it, they have come up with a little nickname.
“I’m in charge of the bug,” Dowe boasted.
The little organism is known as an archaea. They are some of the oldest organisms on earth, but really only identified as such in the 1970s. Before that, scientists usually mistook them for bacteria. But they’re not.
Think of our little green friends as an armored division version of bacteria. They are smaller than bacteria and have super-durable cell walls that allow them to exist in extreme conditions. Archaea are the little organisms that can survive hot temperature and extreme pressure.
“Deep sea well vents in the ocean,” said Dowe. “Thermal pools at Yellowstone. We find them at wastewater treatment plants.”
Researchers at The University of Chicago isolated this particular organism, which takes in hydrogen and carbon dioxide and puts out, methane, better known to most as natural gas.
“Renewable natural gas,” NREL researcher Kevin Harrison likes to call it. Unlike the natural gas brought to the surface in oil and gas mining, renewable natural gas has a couple of environmentally friendly properties. First, it is considered “carbon neutral.” That’s because it uses up about as much carbon in creating methane as it gives off when that natural gas is burned as a fuel. Secondly, because it is an organism, it reproduces and is in effect self-sustaining.
But where do you get the hydrogen and carbon dioxide?
The carbon dioxide is easy to find. “We could go to a dairy, a wastewater treatment plant, an ethanol plant. We could go to a coal burning plant where they are releasing CO2 into the atmosphere,” said Harrison.
Getting the hydrogen is actually the answer to yet another problem. That’s because renewable energy sources like wind and solar produce more energy at certain times when the wind is blowing or the sun shining, but little to none when it’s cloudy, night, or the winds stop. Battery storage is one option.
This is new.
Experts at NREL can take the electricity generated a peak times by wind and solar and use it to split water in a process known as electrolysis. That busts up the H2O into hydrogen and oxygen. The oxygen is handy, but what they’re really after right now is the hydrogen. They pump it to big tanks by a tower outside called a bioreactor, where the archaea reside awaiting their job.
“They love warm temperatures, upwards of 140 degrees Fahrenheit,” said Dowe. “And they love high pressure.”
So in their tank they have their bug, hydrogen, carbon dioxide and a few salts and… bingo! Methane is produced – almost immediately. The other great news is that there is already an infrastructure for natural gas delivery.
The renewable natural gas can, “Go out to homes and businesses, or refuel a truck or a bus. It’s a direct replacement,” said Harrison. “And we’re sort of greening or de-carbonizing the natural gas grid, much like we’re greening and de-carbonizing the electrical grid.”
Energy companies are already interested. SoCalGas is a partner in the research along with the Department of Energy. SoCalGas is a huge supplier in Southern California that meets the needs of over 20 million people. They have huge underground storage facilities where natural gas is held in reserve.
The renewable natural gas produced by the bug could go into storage, and energy produced by wind and solar could be held for use at peak times.
The bioreactors could also be installed on a smaller scale – factories wishing to dispose of carbon emissions could find it environmentally positive and cost effective. That is not to say there are not challenges. Hydrogen is a very tiny element.
“It likes to fly,” said Dowe. They are working on keeping it in the solution. This archaea is naturally occurring. It even has a sort-of off switch.
If you take the bioreactor down from 140 degrees to room temperature, “It just kind of goes to sleep,” said Dowe. “And stops producing more of themselves and more methane. You can start it up in the morning, warm it up, provide the pressure, give it its nutrients and its gases it makes the methane and then at the end of the day you can turn all of that off.”
It means a biological answer to our energy future. An entirely new twist.
Pretty neat stuff for a bug.