Energy from floating algae pods Jonathan Trent

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 we put it just under water and

we fill it with wastewater in 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 an 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

canola or jatropha or palm and that tall

graph there shows what microalgae can

contribute that is to say microalgae

contributes between 2000 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

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 wastewater treatment plants are

they’re embedded in the cities it’s this

in city of San Francisco which has 900

miles of sewer pipes under the city

already and it releases its wastewater

offshore so different cities around the

world treat their wastewater differently

some cities process it some cities just

release the water but in all cases the

water this released is perfectly out of

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 and that’s we 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 by

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 struck by

lightning the wastewater that leaks out

is the water that already now goes into

that coastal environment and the algae

that leaked out or biodegradable and

because they’re living in wastewater

they’re freshwater algae which means

they can’t live in salt water so they

die the plastic will build it out it was

some kind of well known plastic that we

have good experience with and we’ll

rebuild our modules to be able to use

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

ice 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

and other organisms in the ocean will

become enhance 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 sea

water tanks to test some of these ideas

we also set up experiments in San

Francisco at one of the three wastewater

treatment plants again a facility to

test ideas and finally we wanted to see

where we could look at what the impact

of the structure would be in the marine

environment and we set up a field site

at a place called mas landing marine lab

in Monterey Bay where we work in a

harbor to see what impact this would

have on marine organisms the laboratory

that we’ve set up in Santa Cruz was our

skunk works 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

wastewater 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 pbr’s these were the

structures that will be floating at

surface made out of some inexpensive

plastic material that will allow the

algae to grow and we 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

wastewater with algae of art

choice in it and we circulated through

this floating structure this tubular

flexible plastic structure and

circulates through this thing and

there’s sunlight of courses at the

surface and 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 this 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 and 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

algae is 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 them

to develop a cleaning procedure and we

also looked at help sea birds and marine

mammals interacted and in fact you see

here a sea otter that found this

incredibly interesting and what’s

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 a 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 this small scale

but how would we build it on this

enormous

Gill that 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 then

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 a

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 the 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 wastewater 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 weighted treat wastewater

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 shellfish aquaculture 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

used in fields right now as plastic

mulch and this is plastic that’s making

these tiny little green houses right

along the surface of the soil and this

provides warm

the soil to increase the growing season

it allows us to control weeds and of

course it makes watering much more

efficient so the omega system will be

part of this type of a outcome and that

when we’re finished using in the marine

environment will be using it hopefully

on fields where are we going to put this

and in 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 wastewater

if we imagine a five-day retention time

for the system we need 325 million

gallons to accommodate and that would be

about twelve hundred and eighty acres of

these omega modules floating in san

francisco bay well that’s less than 1%

of the service area of the bay it would

produce at 2,000 gallons per acre per

year it would produce over two million

gallons of fuel which is about twenty

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 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 enroute i discovered that

what’s really required for

sustainability is integration more than

innervation long-term I have great faith

in our collective and connected

ingenuity I think there’s almost no

limit to what we can accomplish if we’re

radically open and we don’t care who

gets the credit

sustainable solutions for our future

problems are going to be diverse and

they’re going to be many I think we need

to consider everything everything from

alpha to Omega thank

it’s done mr. quake first if you

Jonathan do 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 so it’s

really gotten to a stage now in NASA

where they would like to spin it out

into something which will 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 opened 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 so that’s

interesting you’re not patenting it

you’re publishing it it’s absolutely all

right thank you so much thank you