Coal and algae, the ‘perfect’ clean energy pair

Whoever said coal couldn’t be a part of a green energy future must have missed this recent spot on NBC Nightly News.

Algae—the green slimy stuff you find in ponds and lakes—is being tested as an alternative fuel source for cars. In fact, experts believe that algae has the capability to displace petroleum diesel to the tune of 66 billion gallons of oil. What’s more, algae grows remarkably fast. Rather than harvesting once or twice a year, scientists can harvest algae every couple of days.

The caveat of this fast-growing super fuel? Giving it enough to eat. Every pound of algae consumes more than two pounds of carbon dioxide. The solution: grow the algae where there’s CO2 to spare.

Scientists conducted a small-scale test at an Arizona plant, pumping CO2 from a coal-fired plant into a tank of algae. The result was enough for one scientist to declare, “We’re able to convert a renewable product into fuel and at the same time consume CO2—it’s a perfect story.”

Comments

[Allen N Wollscheidt]

One takes fuel (coal), burns it producing energy and CO2; he then takes the CO2, feeds it to algae, producing more fuel which presumably may then be dried and burned to produce more energy.

I smell perpetual motion here, at least if it is assumied that there is net energy output from the described process.

[Frank m]

I have a degree in Natural Science and there is NO SUCH THING AS CLEAN COAL!!!

The energy and cost involved in scrubbing the emissions defeats the process.

We need to invest in TRUE clean technologies like solar, wind and where available geothermal.

This only serves to prolong the death of this industry. Invest in true clean technologies and let burning of ALL fossil fuels become a thing of the past.

We need to fundamentaly change our energy resources and now that we are in such a hole it is a good idea to dig us out using all these new technologies and putting the old behind.

[Megan from ACCCE]

Thanks for your comment, Frank. A couple of questions for you in response:

How do you expect intermittent power resources like wind and solar to replace fuels (like coal) that produce power on demand?

Moreover, if you have confidence in overcoming those hurdles with renewables, why are you so pessimistic about overcoming other hurdles with fossil fuels—especially when you consider how close we're getting on the CCS front? (Link: Domestic and International CCS Projects, December 2008.)

[Clean Diesel]

The experts believe is great and thanks to provide all.

[Jon]

And what about all of the mercury? Tons per year. If we are going to be serious about energy security we must figure the true costs of coal-spewing tons of mercury; bursting ash ponds, CO2, particulate matter. Clean coal is a dead end. There are too many other options than throwing money down a hole for this.

[Megan from ACCCE]

Jon,

It's important to remember that coal accounts for nearly half of America's electricity mix now. Currently, renewables like wind and solar don't stack up the baseload capabilities of coal.

It's because coal continues to play such a large role in our energy mix (which we hope will become more balanced with the support of renewables) that we need to invest in ways to use it as cleanly as possible.

[Michael C Weir]

I am an inventor and discovered a way to increase algae grown in open ponds to such an extent that it is profitable to grow algae to use as a fuel, instead of coal. In that way, there is no sulfur to scrub, there is no mercury to get rid of. I have termed this algae "GREEN COAL

[lawsci]

Re: Perpetual Motion- the algae uses solar energy via photosynthesis to sequester the CO2, so there is no perpetual motion problem, since the sun provides the necessary energy.

If the algae can be engineered to produce a kind of biodiesel, then the carbon from the coal gets used a second time (in cars) before being released.

There is a net reduction in carbon emissions because the algae diesel presumably replaces gasoline.