Energy from floating algae pods

Call it "fuel without fossils": Jonathan Trent is working on a plan to grow new biofuel by farming micro-algae in floating offshore pods that eat wastewater from cities. Hear his team's bold vision for Project OMEGA (Offshore Membrane Enclosures for Growing Algae) and how it might power the future.

Some years ago, I set out to try to understand

if there was a possibility to develop biofuels

on a scale that would actually compete with fossil fuels

but not compete with agriculture for water,

fertilizer or land.

So here's what I came up with.

Imagine that we build an enclosure where we put it

just underwater, and we fill it with wastewater

and some form of microalgae that produces oil,

and we make it out of some kind of flexible material

that moves with waves underwater,

and the system that we're going to build, of course,

will use solar energy to grow the algae,

and they use CO2, which is good,

and they produce oxygen as they grow.

The algae that grow are in a container that

distributes the heat to the surrounding water,

and you can harvest them and make biofuels

and cosmetics and fertilizer and animal feed,

and of course you'd have to make a large area of this,

so you'd have to worry about other stakeholders

like fishermen and ships and such things, but hey,

we're talking about biofuels,

and we know the importance of potentially getting

an alternative liquid fuel.

Why are we talking about microalgae?

Here you see a graph showing you the different types

of crops that are being considered for making biofuels,

so you can see some things like soybean,

which makes 50 gallons per acre per year,

or sunflower or canola or jatropha or palm, and that

tall graph there shows what microalgae can contribute.

That is to say, microalgae contributes between 2,000

and 5,000 gallons per acre per year,

compared to the 50 gallons per acre per year from soy.

So what are microalgae? Microalgae are micro --

that is, they're extremely small, as you can see here

a picture of those single-celled organisms

compared to a human hair.

Those small organisms have been around

for millions of years and there's thousands

of different species of microalgae in the world,

some of which are the fastest-growing plants on the planet,

and produce, as I just showed you, lots and lots of oil.

Now, why do we want to do this offshore?

Well, the reason we're doing this offshore is because

if you look at our coastal cities, there isn't a choice,

because we're going to use waste water, as I suggested,

and if you look at where most of the waste water

treatment plants are, they're embedded in the cities.

This is the city of San Francisco, which has 900 miles

of sewer pipes under the city already,

and it releases its waste water offshore.

So different cities around the world treat their waste water

differently. Some cities process it.

Some cities just release the water.

But in all cases, the water that's released is

perfectly adequate for growing microalgae.

So let's envision what the system might look like.

We call it OMEGA, which is an acronym for

Offshore Membrane Enclosures for Growing Algae.

At NASA, you have to have good acronyms.

So how does it work? I sort of showed you how it works already.

We put waste water and some source of CO2

into our floating structure,

and the waste water provides nutrients for the algae to grow,

and they sequester CO2 that would otherwise go off

into the atmosphere as a greenhouse gas.

They of course use solar energy to grow,

and the wave energy on the surface provides energy

for mixing the algae, and the temperature

is controlled by the surrounding water temperature.

The algae that grow produce oxygen, as I've mentioned,

and they also produce biofuels and fertilizer and food and

other bi-algal products of interest.

And the system is contained. What do I mean by that?

It's modular. Let's say something happens that's

totally unexpected to one of the modules.

It leaks. It's struck by lightning.

The waste water that leaks out is water that already now

goes into that coastal environment, and

the algae that leak out are biodegradable,

and because they're living in waste water,

they're fresh water algae, which means they can't

live in salt water, so they die.

The plastic we'll build it out of is some kind of

well-known plastic that we have good experience with, and

we'll rebuild our modules to be able to reuse them again.

So we may be able to go beyond that when thinking about

this system that I'm showing you, and that is to say

we need to think in terms of the water, the fresh water,

which is also going to be an issue in the future,

and we're working on methods now

for recovering the waste water.

The other thing to consider is the structure itself.

It provides a surface for things in the ocean,

and this surface, which is covered by seaweeds

and other organisms in the ocean,

will become enhanced marine habitat

so it increases biodiversity.

And finally, because it's an offshore structure,

we can think in terms of how it might contribute

to an aquaculture activity offshore.

So you're probably thinking, "Gee, this sounds

like a good idea. What can we do to try to see if it's real?"

Well, I set up laboratories in Santa Cruz

at the California Fish and Game facility,

and that facility allowed us to have big seawater tanks

to test some of these ideas.

We also set up experiments in San Francisco

at one of the three waste water treatment plants,

again a facility to test ideas.

And finally, we wanted to see where we could look at

what the impact of this structure would be

in the marine environment, and we set up a field site

at a place called Moss Landing Marine Lab

in Monterey Bay, where we worked in a harbor

to see what impact this would have on marine organisms.

The laboratory that we set up in Santa Cruz was our skunkworks.

It was a place where we were growing algae

and welding plastic and building tools

and making a lot of mistakes,

or, as Edison said, we were

finding the 10,000 ways that the system wouldn't work.

Now, we grew algae in waste water, and we built tools

that allowed us to get into the lives of algae

so that we could monitor the way they grow,

what makes them happy, how do we make sure that

we're going to have a culture that will survive and thrive.

So the most important feature that we needed to develop were these

so-called photobioreactors, or PBRs.

These were the structures that would be floating at the

surface made out of some inexpensive plastic material

that'll allow the algae to grow, and we had built lots and lots

of designs, most of which were horrible failures,

and when we finally got to a design that worked,

at about 30 gallons, we scaled it up

to 450 gallons in San Francisco.

So let me show you how the system works.

We basically take waste water with algae of our choice in it,

and we circulate it through this floating structure,

this tubular, flexible plastic structure,

and it circulates through this thing,

and there's sunlight of course, it's at the surface,

and the algae grow on the nutrients.

But this is a bit like putting your head in a plastic bag.

The algae are not going to suffocate because of CO2,

as we would.

They suffocate because they produce oxygen, and they

don't really suffocate, but the oxygen that they produce

is problematic, and they use up all the CO2.

So the next thing we had to figure out was how we could

remove the oxygen, which we did by building this column

which circulated some of the water,

and put back CO2, which we did by bubbling the system

before we recirculated the water.

And what you see here is the prototype,

which was the first attempt at building this type of column.

The larger column that we then installed in San Francisco

in the installed system.

So the column actually had another very nice feature,

and that is the algae settle in the column,

and this allowed us to accumulate the algal biomass

in a context where we could easily harvest it.

So we would remove the algaes that concentrated

in the bottom of this column, and then we could

harvest that by a procedure where you float the algae

to the surface and can skim it off with a net.

So we wanted to also investigate what would be the impact

of this system in the marine environment,

and I mentioned we set up this experiment at a field site

in Moss Landing Marine Lab.

Well, we found of course that this material became

overgrown with algae, and we needed then to develop

a cleaning procedure, and we also looked at how

seabirds and marine mammals interacted, and in fact you

see here a sea otter that found this incredibly interesting,

and would periodically work its way across this little

floating water bed, and we wanted to hire this guy

or train him to be able to clean the surface

of these things, but that's for the future.

Now really what we were doing,

we were working in four areas.

Our research covered the biology of the system,

which included studying the way algae grew,

but also what eats the algae, and what kills the algae.

We did engineering to understand what we would need

to be able to do to build this structure,

not only on the small scale, but how we would build it

on this enormous scale that will ultimately be required.

I mentioned we looked at birds and marine mammals

and looked at basically the environmental impact

of the system, and finally we looked at the economics,

and what I mean by economics is,

what is the energy required to run the system?

Do you get more energy out of the system

than you have to put into the system

to be able to make the system run?

And what about operating costs?

And what about capital costs?

And what about, just, the whole economic structure?

So let me tell you that it's not going to be easy,

and there's lots more work to do in all four

of those areas to be able to really make the system work.

But we don't have a lot of time, and I'd like to show you

the artist's conception of how this system might look

if we find ourselves in a protected bay

somewhere in the world, and we have in the background

in this image, the waste water treatment plant

and a source of flue gas for the CO2,

but when you do the economics of this system,

you find that in fact it will be difficult to make it work.

Unless you look at the system as a way to treat waste water,

sequester carbon, and potentially for photovoltaic panels

or wave energy or even wind energy,

and if you start thinking in terms of

integrating all of these different activities,

you could also include in such a facility aquaculture.

So we would have under this system a shellfish aquaculture

where we're growing mussels or scallops.

We'd be growing oysters and things

that would be producing high value products and food,

and this would be a market driver as we build the system

to larger and larger scales so that it becomes, ultimately,

competitive with the idea of doing it for fuels.

So there's always a big question that comes up,

because plastic in the ocean has got a really bad reputation

right now, and so we've been thinking cradle to cradle.

What are we going to do with all this plastic that we're

going to need to use in our marine environment?

Well, I don't know if you know about this,

but in California, there's a huge amount of plastic

that's used in fields right now as plastic mulch,

and this is plastic that's making these tiny little greenhouses

right along the surface of the soil, and this provides

warming the soil to increase the growing season,

it allows us to control weeds,

and, of course, it makes the watering much more efficient.

So the OMEGA system will be part

of this type of an outcome, and that when we're finished

using it in the marine environment, we'll be using it,

hopefully, on fields.

Where are we going to put this,

and what will it look like offshore?

Here's an image of what we could do in San Francisco Bay.

San Francisco produces 65 million gallons a day

of waste water. If we imagine a five-day retention time

for this system, we'd need 325 million gallons

to accomodate, and that would be about 1,280 acres

of these OMEGA modules floating in San Francisco Bay.

Well, that's less than one percent

of the surface area of the bay.

It would produce, at 2,000 gallons per acre per year,

it would produce over 2 million gallons of fuel,

which is about 20 percent of the biodiesel,

or of the diesel that would be required in San Francisco,

and that's without doing anything about efficiency.

Where else could we potentially put this system?

There's lots of possibilities.

There's, of course, San Francisco Bay, as I mentioned.

San Diego Bay is another example,

Mobile Bay or Chesapeake Bay, but the reality is,

as sea level rises, there's going to be lots and lots

of new opportunities to consider. (Laughter)

So what I'm telling you about is a system

of integrated activities.

Biofuels production is integrated with alternative energy

is integrated with aquaculture.

I set out to find a pathway

to innovative production of sustainable biofuels,

and en route I discovered that what's really required

for sustainability is integration more than innovation.

Long term, I have great faith

in our collective and connected ingenuity.

I think there is almost no limit to what we can accomplish

if we are radically open

and we don't care who gets the credit.

Sustainable solutions for our future problems

are going to be diverse

and are going to be many.

I think we need to consider everything,

everything from alpha to OMEGA.

Thank you. (Applause)

(Applause)

Chris Anderson: Just a quick question for you, Jonathan.

Can this project continue to move forward within

NASA or do you need some very ambitious

green energy fund to come and take it by the throat?

Jonathan Trent: So it's really gotten to a stage now

in NASA where they would like to spin it out into something

which would go offshore, and there are a lot of issues

with doing it in the United States because of limited

permitting issues and the time required to get permits

to do things offshore.

It really requires, at this point, people on the outside,

and we're being radically open with this technology

in which we're going to launch it out there

for anybody and everybody who's interested

to take it on and try to make it real.

CA: So that's interesting. You're not patenting it.

You're publishing it.

JT: Absolutely.

CA: All right. Thank you so much.

JT: Thank you. (Applause)