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Leave the Algae Alone

While the first generation of biofuels is wreaking havoc on the environment and the food markets, the second generation is set to make things even worse.

Image: This image shows a tubular glass photobioreactor for the cultivation of microalgae and other photosynthetic organisms. Credit: IGV Biotech (CC-BY SA 3.0).
Image: This image shows a tubular glass photobioreactor for the cultivation of microalgae and other photosynthetic organisms. Credit: IGV Biotech (CC-BY SA 3.0).
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Since it has become clear that ethanol and biodiesel made from food crops are doing more harm than good, the hope for finding a substitute for oil has shifted to algae and cellulose. If we can believe the advocates of this ‘second generation’ of biofuels, these combustibles will deliver way more energy than it takes to make them, without threatening the world’s food and water supplies. Upon taking a closer look, however, this is very hard to believe. They might even cause bigger problems than biofuels made from food crops. Maybe this time around we could sort this out before the damage gets done?

The biofuel disaster

Just two years ago, ethanol and biodiesel were heralded by almost everybody as a green substitute for oil. Today, almost everybody realizes that it is a foolish idea. Several studies have confirmed by now that it takes as much or even more energy to produce biofuels than they can deliver themselves.

That’s because the crops have to be planted, fertilized, harvested, transported, and converted into fuel, all processes that require fossil energy. If one also takes into account the land that is cleared to plant the energy crops, biofuels have become an extra source of greenhouse gases, while they were meant to lower them. Biofuels also helped to fuel a rise in food prices by competing for agricultural land. And very recently it also became clear that their production poisons water bodies.

In spite of this horrible record, both the European Union and the United States keep encouraging ethanol and biodiesel, mainly with the excuse that there is a ‘second generation’ of green fuels on the way, particularly cellulosic ethanol and algal fuel, which have no harmful effects. Sadly, this promises to be another dangerous illusion.

Cellulosic ethanol disaster

It is too early to say whether or not cellulosic ethanol can ever be produced with a net energy gain as a result – at the moment, it is impossible. We can only hope that scientists will never succeed, because what we do know for sure is that cellulosic ethanol will be an even larger threat to the world’s food supply than the first generation of biofuels.

Cellulosic ethanol is not made from the edible parts of crops, but from their stalks, roots and leaves. It can also be made of non-edible plants, like switchgrass. Therefore, at first sight, it seems unlikely that turning cellulose into fuel could present a danger for agriculture. However, there is one, literally invisible problem: the soil.

In nature, the concept of waste does not exist. The so-called “waste” that we plan to transform into fuel, is an essential element to keep the soil productive. Leaves, twigs and stalks are decomposed by underground organisms, which turn it into humus that can feed a next generation of plants.

If you take away this material, the soil will become less and less fertile until all you are left with is a desert. Of course, this process can be offset by adding more and more artificial fertilizers. But, here’s the rub: fertilizers are made from fossil fuels. Almost 30 percent of energy use in agriculture is attributed to fertilizer production (both their production process and their content). This means that the more energy we produce from cellulose, the more energy we will need to keep the soil fertile. In short: this makes no sense.

The first generation of biofuels might endanger the world’s food supply, but that process is reversible. We can decide at any moment to change our minds and use the corn to make food instead of fuel. A similar deployment of cellulosic fuels would destroy our agricultural soils, without any chance to repair them afterwards. We will have mined the soil – a process that is irreversible, because when the soil becomes too exhausted, even fertilizers are of no help. Cellulosic ethanol is a dangerous illusion. And if you don’t believe me, ask any soil scientist.

Nevertheless, as was announced earlier this week, the first cellulosic ethanol plant is scheduled to start working in 2009 (even despite the fact that scientists agree that a net energy gain is not yet possible).

The algae fuel disaster

Also earlier this week, the first algal fuel production facility went online and that generated lots of excitement. If we can believe the hype, it will not take long before we drive our cars and fly our planes on fuel made by algae. The figures sound impressive. Algae are expected to be able to produce 10,000 gallons of fuel per acre per year (some say 20,000 gallons), compared to 700 gallons for palm oil and less than 100 gallons for corn and soy.

Algae could also be used as a jet fuel and as a source to make plastics and detergents. Moreover, all this can be done with nothing more than sunlight and CO2 – and without the need for any potable water. If algal fuel plants are placed next to fossil fuel plants, as some companies are planning to do, the algae could even capture the CO2 from the emissions of the coal or gas plant. As one ecogeek summarized; “Welcome to the future, where single-celled plants eat our pollution and power our cars.”

There are very detailed figures on the amount of energy that will come out of the process, yet it is very hard to find any information on the energy and resources needed to make this energy output possible.

This sounds too good to be true. If you take a closer look at the claims of these companies, essential information seems to be missing. They present very detailed figures on the amount of energy that will come out of the process, yet it is very hard if not impossible to find any information on the energy and resources needed to make this energy output possible.

If algae don’t produce more energy than it takes to produce them, driving cars on algal fuel does not make much sense. And if they also use resources that are needed by agriculture, the game might not be worth the candle. These are important questions, as we have learned from the ethanol and biodiesel fiasco, yet nobody seems to wait for the answers.

Some twenty companies are planning commercial facilities to make algal fuel, often backed up by petroleum businesses and government subsidies (see here and here for an overview).

Water in the desert

Algae have higher photosynthetic efficiencies than most plants, and they grow much faster. Up to 50 percent of their body weight is oil, compared to about 20 percent for oil-palm trees. They don’t need fertile ground, so that they can be grown on soil that is not suitable for agriculture.

All this sounds very good, but algae also need a few things, most notably: a lot of sunshine and massive amounts of water. To grow algae, you also need phosphorus (besides other minerals), an element that is very much needed by agriculture.

Most algae are grown in brackish or salt water. That sounds as if water is no issue, since our planet has not a shortage of salt water. However, just like solar energy plants, algae plants are best located in very sunny regions, like deserts. But, in deserts, and in very sunny places in general, there is not much water to find. That’s not a problem for solar plants, because they don’t need it. But, how are you going to get seawater to your desert algae plant? Check the websites of all these companies: not a word about it.

There are not that many possibilities. You can transport seawater to the desert, but that’s going to cost you an awful lot of energy, probably more than what can be produced by the algae. You can also take freshwater from more nearby regions or underground aquifers and turn it into artificial seawater. But, you promised that algal fuel would not compete with food production. A third option is to put your algae plant next to the sea.

Algae need a lot of sunshine and huge amounts of water - how do you get seawater to the desert?

Now, there are places which are both close to the sea and have lots of sun. But chances are slim that they are as cheap and abandoned like deserts are. Most likely, they are already filled up with tourists and hotels, to name one possibility. So you might be forced to look for a less sunny place close to the sea – which inevitably means that your energy efficiency is going down. Which again raises the question: will the algae deliver more fuel than is needed to make them?

How much water does algae production need? This information is nowhere to find. “A lot” would be a good bet for an answer, since it’s not enough to fill up the ponds or tanks just once. The water has to be supplemented regularly. Being able to produce 10,000 gallons of fuel per acre per year might sound impressive, but what really counts is how many gallons of fuel you can produce with a certain amount of water.


The water issue is not the only “detail” that threatens the energy efficiency of algal fuel. Compared to other plants, the photosynthetic efficiency of algae is high – almost 3 times that of sugar cane for instance. Compared to solar energy, however, the energy efficiency of algae is very low – around 1 percent, while solar panels have an efficiency of at least 10 percent, and solar thermal gets 20 percent and more.

So why would we choose algae over solar energy? One reason might be that it takes quite some energy to produce solar panels, while algae can be grown in an open shallow pond with nothing else but sunshine and CO2, which the organisms take from the atmosphere. You will still need energy to turn the algae into a liquid fuel, but other than that no energy input is needed.

However, these low-tech methods (comparable to growing corn, soy or palm trees to make ethanol or biodiesel) are being left behind for more efficient ones, using closed glass or polycarbonate bioreactors and an array of high-tech equipment to keep the algae in optimal conditions.

Even though some companies still prefer open ponds (like the PetroSun plant that started production last week), this method has serious drawbacks. The main problem is contamination by other kinds of algae and organisms, which can replace the energy producing algae in no time. Ponds also need a lot of space, because sunlight only penetrates the upper layers of a water body. It’s the surface of the pond that counts, not the depth.

The laws of physics

Transparent aquariums (called closed bio-reactors) solve all the problems of open ponds. These bioreactors can be placed inclined or suspended from the roof of a greenhouse so that they can catch more sun on a given surface. And since they are closed, no other organisms can enter. However, this method introduces a host of other issues. Bioreactors have a higher efficiency, but they also use considerably more energy.

First of all, you have to build an array of structures: the glass or polycarbonate containers themselves, the metal frames, the greenhouses. The production of all this equipment might consume less energy (and money) per square meter than the production of solar panels, but you need much more of it because algae are less efficient than solar plants.

Moreover, in closed bioreactors, CO2 has to be added artificially. This is done by bubbling air through the water by means of gas pumps, a process that needs energy. Furthermore, the containers have to be emptied and cleaned regularly, they have to be sterilized, the water has to be kept at a certain temperature, and minerals have to be added continuously (because also here, just as with cellulosic ethanol, “waste” materials are being removed). All these processes demand extra energy.

Are algal fuel producers taking these factors into account when they claim efficiencies that are 100 times higher than the ones from biodiesel and ethanol? Only they know. It could be that these businesses are greatly overestimating their energy gains in order to attract capital.

One of the few critics of algal fuel, Krassen Dimitrov, calculated that the figures of GreenFuel Technologies are defying the laws of physics. The company says that he is wrong, but his calculations surely look more convincing than the virtually non-existant information on their website (update May 2009: GreenFuel Technologies shuts down).

Feeding algae from smokestacks

Several companies plan to hook up their production facilities to a fossil fuel energy plant, in order to capture the CO2 and nitrogen emissions and “feed” them to the algae. This method is hailed as a way of reducing greenhouse gases emitted by coal and gas plants, which is a ridiculous claim. It’s very curious that this capturing technology is criticized when used in the context of “clean” coal, but applauded when it is used to make algal fuel. In both cases, capturing CO2 from smokestacks raises the energy use of the power plant by at least 20 percent.

It’s curious that capturing CO2 from power plants is criticized when used in the context of ‘clean’ coal, but applauded when it is used to make algal fuel.

That not only makes the technology very expensive, it also means that more coal or gas has to be mined, transported and burned. Algal fuel can even be considered a worse idea than “clean” coal. In the “clean” coal strategy, at least the CO2 is captured with the intention to store it underground.

In the case of algae, the CO2 is captured only with the intention to release in the air some time later, by a car engine. Last but not least, capturing CO2 from power plants ties algal fuel production to fossil fuels. If we switch to solar energy, where will the algal fuel producers get their CO2 from?

Outsourcing energy use

Are algae producers considering the extra use of energy that arises by the capture of the CO2 when they claim that algae can deliver 100 times more energy than first generation biofuels? This seems very doubtful. All these claims have one thing in common: they focus only on a small part of the total energy conversion chain.

A very good example is the story of Solazyme, a company that cultivates (genetically modified) algae in non-transparent steel containers, similar to those of breweries. In this case the algae do not get their energy from the sun, but from sugar that is fed to them. This method, says the company, makes them produce 1,000 times more oil than they do in sunlight, because sugar is a much more concentrated form of energy than sunlight.

But, where does the sugar come from? The researchers simply leave that part of the process out of their calculation, and nobody seems to care. Growing sugar cane of course requires significant amounts of energy, land and water.

In fact, by turning off photosynthesis, the researchers eliminate the only advantage of algae compared to other plants: their higher energetic efficiency. The photosynthetic efficiency of sugar cane is not even half that of algae, which means that if the whole energy chain would be considered, this process can only be worse than that of algae produced in transparent bioreactors.

Stop this madness

While the first generation of biofuels is wreaking havoc on the environment and the food markets, the second generation is getting ready to make things only worse. Behind the scenes, scientists are already working on the third generation, whatever that may be.

In five or ten years time, when it becomes clear that algal fuel is devouring our water and energy resources and cellulosic ethanol is mining our agricultural soils, we will be promised that the third generation will again solve all the problems of the previous generation.

Producing fuels out of food crops could be a useful and sustainable solution if our energy consumption would not be so ridiculously high

It might be a better solution to bury the whole idea of biofuels right here and now and focus on real solutions. The trouble with biofuels is not the technology, but our unrealistic expectations. Producing fuels out of food crops could be a useful and sustainable solution if our energy consumption would not be so ridiculously high.

All our habits, machines and toys are built upon an extremely concentrated form of energy, fossil oil, and trying to replace that fuel with a much less concentrated form is simply impossible. In 2003, Jeffrey Dukes calculated that 90 tons of prehistoric plants and algae were needed to build up one gallon of gasoline. We burn this amount of organic material to drive 25 miles to pick up some groceries.

In one year, the world burns up 400 years of prehistoric plant and algae material. How can we ever expect to fulfill even a small part of our fuel needs by counting on present plant and algae material? The problem we have to fix is our energy consumption. Biofuels, from whatever generation, only distract us from what really should be done.


  1. Scientists warn of lack of vital phosphorus as biofuels raise demand (June 2008).

  2. How much energy does it take to construct algal factories? Chris Rhodes from Energy Balance made an eye-opening calculation (November 2008).

  3. The water footprint of bioenergy (April 2009): barley, cassava, maize, potato, rapeseed, rice, rye, sorghum, soybean, sugar beet, sugar cane, wheat and jatropha. Algal fuel is not included, but the results are significant. It takes 1,400 to 20,000 litres of water to produce 1 litre of biofuel.

  4. Amid a sea of troubles, ethanol now has an antibiotics problem (April 2009).

  5. If you grow jatropha in marginal conditions, you can expect marginal yields. (May 2009)

  6. GreenFuel Technologies shuts down. (May 2009)

  7. Producing biofuels from algae generates high levels of greenhouse gases (January 2010)


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Floating Algae farms.

Kris De Decker

That is such a bizarre argument, Jason.

From the moment that it takes more energy to produce a source of energy than the energy it can deliver, it is no longer a source of energy. If it takes more oil to produce biofuels than it would take to power your car directly with oil, then what is the use of biofuel?

This does not only apply to alternative energy. From the moment it takes more than 1 litre of oil to dig up 1 litre of oil, oil is no longer a source of energy.

This is not just an opinion of Low-tech Magazine, it is common sense. Paste this into your search engine: “Energy Return On Energy Invested (EROEI)”


Then your blog software is as broken as your claims.

Uncle B

No one single magic wand solution is going to cover all the energy problems faced by todays world. All of the solutions, combined with any newer 21st century breakthroughs are candidates. Any combination of them along with the inevitable lifestyle changes that are occurring as we speak will accommodate the conditions in the world. It is a rare and welcome opportunity for capitalist/entrepreneurs when life-forces cause shifts and openings are created in the market place for new and better products and systems. Thank God for anxious predatory rabidly hungry capitalists and greedy investors. Because of them, we will get the best of the best and suffer the transitions occurring in the world less than the people in other countries.


Just because the US might not have an abundance of sunny, coastal areas without development doesn’t mean the rest of the world doesn’t. What about the possibility of algae farms in Australia, Peru, Chile, Baja California?


OK, I take any plant/algae and ferment or process it to remove either ethanol or hydrocarbons. The residue is fertilizer. The manure remains. Why have you assumed it will not return to the soil?

There are many farming techniques with reduced fossil fuel impact and that our fore-fathers used with great success. We can and will relearn them. As well, run the tractor on bio-fuel and you have further leveraged your crop.

Already in Africa old techniques are being relearned and water conserved. Many of these marginal crops use land and species not fit for food production but which provide a cash crop for otherwise impoverished peoples.

While the present ‘green hype’ is full of as much manure as the products of which we are speaking, the doomspeak won’t help either.

All these fuels are just a chemical storage of energy. The key is to get it from the sun to the fuel with a minimum of collateral damage.


Whilst I agree that Corn that can be used to feed humans and livestock should not to be turned into ethanol and deforestation to make Palm Oil is unacceptable, I cannot accept this ECO band wagon nonsense about ALL Biofuels being of the devil.

On environmental grounds we have limited land resources. Biofuel should be used locally and in the most efficient engines. Ethanol combustion is less thermodynamically efficient than Petrol/Gasoline which in turn is worse than Diesel. So for transport and Heating/Cooking purposes Bio Diesel makes more sense. Especially if is made from Jatropha or Elephant grass.

The latter must be grown in conjunction with food crops like Maize/Sorgum to benefit the local populace and reduce crop disease.

Jatropha and Elephant grass actually improve soil and water retention which boosts food crop yields. This means “waste” land can be used to grow food and fuel. Projects across sub saharan Africa have demonstrated the feasibilty for local consumption. See:


Hi all,

Kris if you argument is based (mostly) on water consumption, it is a weak argument. There are lots of mistakes in your article. I will only focus on two. Water in the desert, and Phosphorus. There is plenty of water suitable for algae growth in the desert in the form of saline groundwater. Go to any dairy farm and test their effluent to see if there is a deficency in P, I think they may even pay you to take some home with you.

It is good for you to be skeptical, and question the energy budget of algae oil production, but doing a little research may help strengthen your claims.

Judy Cho


I’m Judy, a high school student in Seoul, South Korea. I’m preparing for my debate class and this information is so helpful.

However,there’s a question; even though most algae are grown in salt water, I thought they can also be grown in wastewater… and using wastewater doen’t make any problems.

Another question is that does an algae production facility has to be located in desert? Can’t it be at other extensive regions with a lot of sunshine?

Would you please answer my questions?

It will be a great help for me and my classmates.

Thank you for providing us such an excellent information and I will wait for your comments.

walter Palmer

Hi Kris

What you have to say about some of the dumb ideas that we have tried to put into practice in our economy is true: ethanol from corn is a complete bust. So it’s great to bring some healthy scepticism to the debate about new deas. But the fact is that we need to find the new ideas that will help. It’s a mistake to try and commercialize these technologies before we understand them completely, and of course someone who has invested a lot of dough in bringing the idea to commercial viability doesn’t really want to see the idea challenged. But that just means that we have to work harder at vetting these ideas before they can get into the economy and wreak havoc. There is a very useful role for publicly funded research to play here. At the patent office, new energy schemes need to be screened in a thorough life cycle analysis for their real net energy, land, water, and materials needs.

All that having been said, I find that your criticism of ideas like fuel from algae seems driven by an anti-consumption ideology. Conservation is great but we are 6.7m people and we have to find ways of creating consumable energy from the energy ocean in which we live. We need these ideas to be brought forth and examined carefully; we can’t just pooh pooh them and treat them with disdain.

Based upon our experience, it’s clear that we need to be very careful with new technologies in the future. But one thing that won’t fuel the future is negativity.

kris de decker

@ Falstaff:

“Algae does not ‘require’ CO2 from Coal or other hydrocarbons. It helps, but natural concentrations in the atmosphere will do.”

> Natural CO2 concentrations in the atmosphere are not sufficient to do the job. Only open pond systems make use of natural CO2 and their yield is much lower. Closed systems require artificially added CO2. See the article.

“Then there’s an unfounded assumption throughout, that algae biofuel is somehow like old energy production or agriculture in that it must constantly be replenished.”

> please check the laws of thermodynamics. the perpetuum mobile does not exist.


>>But, in deserts, and in very sunny places in general, there is not much water to find. That’s not a problem for solar plants, because they don’t need it. But, how are you going to get seawater to your desert algae plant?

Come to Australia and look at the thousands of kilometres of ‘salt-affected land’ that was once prime farmland. It will even help stop the ongoing degradation, and trust me, sunlight is not a problem.

Captain Obvious
  1. you scrag OPEN ponds, because of the water required, but ignore covered ponds, perhaps because they work better, and so undermine your propaganda?

( I’m saying that as a former consumer of AdBusters: their political self-importance, and systematic mis-integrity, to push their agenda, blew it for me, finally )

  1. sugar-fed algae are “1000"x as effective as photosynthetic, but are dependent on sugar, which is 1/2 as effective AT PHOTOSYNTHESIS as algae.

So? That doesn’t give the equation, nor does it even acknowledge the fact that most sugar hereabouts is from beets…

1000x/2 strikes me as effective, to use the same simplistic logic used above.

  1. I’m fed up with the DON’T/WON’T!! THERE IS **NO** ANSWER!! ANYWHERE!! attitude of “greenies”.

Humanity NEEDS electricity & fuel, so deal with it.

Or slaughter all the humanity whose lives don’t produce the pretty appearance you want?

Electricity & fuel are required.


THEREFORE changing our electricity & fuel generation to be significantly lower impact is the ONLY sane & pragmatic path.

Perhaps you’d prefer that all the humanity in China & India be blocked from having the same chance we have?

I wouldn’t.

As for deserts & water ( for *covered* ponds ), some aquafiers are briny, and a plastic pipe, buried or elevated, with payment made to the locals who protect it from damage & repair it, to a desert space makes much more sense to me than does the trans-canada-fuel-pipeline nonsense…

DISTRIBUTED resource-generation is better, and more failure-tolerant, than single-points-of-failure.

As for sequestering CO2, the only method I know-of that would really work was pointed out by New Scientist:

charcoal the crop-stubble, & bury it.

Even if 25% of it were sold as fuel ( for oven stoves, or whatever ), it’d be the *only* method of sequestering carbon that’d work well enough to make a difference, now.

( the Pacific Ocean’s thermal-cycle broke in the mid-’70s. bandaids-time was gone in the 1800s )


Captain Obvious

PS: consider HID lamps used as torchieres, instead of a sea of CFLs & LEDs: effective lighting, indirect & efficient.

Consider also mopeds, instead of SUVs: the fuel-consumption would be dropped more deeply than by any other sudden change ( rail takes time to implement, public transit simply can’t serve 80+% of the population every-time-they-need-it, etc )

Pragmatism works.


A study published in the journal Environmental Science and Technology suggests that algae production is energy intensive and can end up emitting more greenhouse gases than it sequesters:

Daniel L. Taylor

“Humanity NEEDS electricity & fuel, so deal with it.”

“It does not. Buy some history books. Start reading, say, in the year 10,000 BC. Then come again.”

Let’s put it another way: humanity is not about to revert to harsh living conditions and <30 year lifespans. To do better, to live well as we have for the past century, we NEED electricity and fuel. If you think you can change that, get ready for a very bloody war because the majority of humanity will take up arms and tear down governments before giving up modern living standards.

One line struck me in this article: “All our habits, machines and toys are built upon an extremely concentrated form of energy, fossil oil, and trying to replace that fuel with a much less concentrated form is simply impossible.”

I agree 110%. Unfortunately this also means that solar and wind will never work.

What’s more concentrated than fossil fuels? The energy bound in the atom. It’s time for man to accept that nuclear power is his only future, and build fission plants until fusion is perfected.

Nothing else makes sense or is rational at this point. And given modern materials technology and reactor designs there is no rational reason for opposing nuclear power. It’s quite frankly more green (read: minimal environmental impact) than even solar.


The author has not done his homework. Algae does not ‘require’ CO2 from Coal or other hydrocarbons. It helps, but natural concentrations in the atmosphere will do. Then there’s an unfounded assumption throughout, that algae biofuel is somehow like old energy production or agriculture in that it must constantly be replenished. That’s not necessarily true. In the case of the enclosure, build one set and grow algae in it for decades. A few acres of (recycled) polycarb every 50 years is no impact to the environment! And it turns out the same may go for the water. Exxon/Venture have a strain the emits hydrocarbon outside the cell, so that it can be extracted without harvesting the algae or water. So again, pump in a large quantity of water, _one time_, top it off occasionally, and you are good for 50 years. Enough with the ‘were running out of everything mindset’, it doesn’t always apply. The only thing that gets used up here is sunshine.

BTW, Southwest Az could run a pipeline 50 miles to the ocean. Less in California.


So, co789, because you cannot conceive of a way to regulate the temperature of a pond, we must all abandon investigation of algae?

Fortunately, the problems that you believe to be insurmountable have already been solved.

First, while algae can be grown in deserts, they don’t have to be. Algae need light, but don’t need to be cooked. In fact, much of the work is being down on marginal land in places where the water supply, particularly as it can be brackish, is abundant.

Water evaporating from ponds can be trapped, condensed and recycled, if it scarce. Covered ponds have been developed and are in use that are effective for this.

Alternatively, using well systems, the water can be 4m deep, and chlorophyll-reduced micro-algae allow light to penetrate to greater depths, while the surface area and therefore water loss and overheating is greatly reduced. This approach is appropriate for deserts. Energy to circulate the pond can be supplied by solar panels or windmills if you wish. Well systems can produce 25 more mass of product per area per day than ponds, while reducing evaporation, overheating, energy inputs and contamination. Take a look at

‘if the algae emit hydrocarbon, then we are talking about a far, far lower yield than if we digested the entire cell.’ This is the equivalent of saying that because the fruit from an apple tree is less than eating the whole tree, we shouldn’t grow apples.

‘There is no way that this can be done as described.’ It has already been done.


OK, so let me get this straight, Falstaff. The water is supposed to last in these tubes for 50 years in the desert. Unless water escapes, the water hosting the algae will get extremely hot. Think of a car on a sunny day in the desert. It gets extremely hot unless there is a great deal of air circulation. But air circulation means that water evaporates, and we will have to expend huge amounts of energy pumping water from the sea to the desert again. Either that, or we have to expend massive amounts of energy to run some mechanical cooling mechanism. There is no way that this can be done in a non-energy intensive way. Water will need to be constantly replenished or the algae will be killed boiling water everyday.

Also, if the algae emit hydrocarbon, then we are talking about a far, far lower yield than if we digested the entire cell. There is no way that this can be done as described.


The statement about the impact of producing ethanol is not true in brazilian ethanol chain. Over there, even the trucks of these companies are ethanol powered. Also, you forgot to mention that the sugar cane absorbs CO2 from the atmosfere, thus compensating the further emissions from the ethanol engine vehicles (that are less pollutant than gasoline autos).


I love this website! (I’m a biased supporter of low/no-tech solutions, so you now have my disclosure statement).

Here we are, a year and a half older, and still no progress on algae fuels. The “open-reactor” issues are still here (e.g. water, temperature, contamination, etc.); the “closed-reactor” start-ups have failed to scale (e.g. input resources become too high). I see the larger energy companies have waded in, perhaps under the cover of getting offset credits under a cap and giveaway system for CO2.

There are a number of assertions and claims made about algae biofuels. Here is a link the close-out report of the DOE program from 1998: I think it is typically a better approach to learn what has gone on in the past, versus relying on bogus scaling calculations based on a poor grasp of engineering.

And perhaps, a year and a half later, give serious consideration to the final point from Kris: “Producing fuels out of food crops could be a useful and sustainable solution if our energy consumption would not be so ridiculously high”

James Smith João Pessoa, Brazil

“Since it has become clear that ethanol and biodiesel made from food crops are doing more harm than good”

There are two problems with this statement. First the grammar. “Since” means “from that time”. The word you want is “because”, which means “for this reason”.

Next, It is not clear that “ethanol made from food crops are doing more harm than good.” Where is your proof of that? Your own opinion? Your own wishful thinking?

Here’s my proof that you are wrong and that casts doubt upon your credibility in the entire post.

Here in Brazil, we are the world’s largest user of ethanol for fuel. This is produced exclusively from sugar cane. All newer vehicles being sold in Brazil are “Flex fuel” meaning they can run on ethanol, gasoline, or any mixture of the two. By law, all gasoline sold in Brazil is 25% ethanol. More, if the dealer is cheating as ethanol is cheaper than gasoline.

As a result, there are vast fields of sugar cane in most areas of Brazil. Is sugar cane a food staple? Obviously not. But sugar is still cheap here and there is no food shortage as there would be if cane were being grown on land needed for food production.

There is actually a surplus of sugar cane and Brazil has complained that they cannot sell sugar profitably in the USA because of the import restrictions imposed to protect the domestic sugar growers.

Brazil has claimed it could put a 2 kilo (≥5 lbs) bag of sugar on every table in America if it were not for those import restrictions.

When you start your article with errors like these, one has to wonder what other things are also wrong that are not so obvious.

I support the effort to reduce pollution and protect the environment, but efforts such as this are misguided and ineffective.

In my own blog, I discuss the real pollution problem and an approach to help it.


What if the oil-producing algae leaks into the ocean? Ocean of oil?

Jason Friedrich

There are flaws in every possible proposal for alternative energy. This website seems to hold proposals to the following standard: “does the alternative technology produce as much or more energy as it consumes, accounting for all types of building and transportation costs”? If not, then research into and pursuit of the alternative technology should be abandoned.

Do YOU produce as much or more energy as you consume during the span of your lifetime? NO? Didn’t think so. Please kill yourself. It’s the only sustainable choice.


I’m astounded by the aggressiveness of the debate, but the heck.

I recently talked to an engineer who had just done an assesment of the productivity of a closed Algae - system near Erding, Bavaria, Germany. They make use of geothermics in his area, and the idea was to use the groundwater after its heat has been depleted, when it’s still warm (40° C) as water to breed algae in. According to the guy, the efficiency was better than PV. I don’t know what, in terms of fertilizer, embedded energy, pumping CO2 into the water etc. went into that calculation.

Technically, the system would look like a bunch of glass-tubes, mounted on racks like PV-cells, with the water and algae beeing pumped through. At the end, the plant as whole is processed. EADS wants to produce fuel for planes and helicopters from this.

Not much hard facts, I know. What struck me was the whole idea of breeding algae in bavaria.

Regarding the whole, rather heated debate: If we burn 400 years of fossil fuel every year, it is clear that we need to lower our ridiculous consumption of energy - especially if we want to have an equal standard of living around the globe!

Alfred Guss

That Zn based “green” technology is a joke - ask any chemist :))) These people are charlatans.

First, you need to mine ZnO and transport it - it requires energy.

Second, at 1200 F ZnO can not “decompose” into Zn and O - it is chemically impossible.That is why they cheat adding carbon - it reacts with ZnO + C - CO + Zn.So CO is a poisonous gas which escapes into atmosphere where it becomes… CO2.So what is “green” about this part of the process? And what they mean by “later biomass will be used to make it non-polluting”? Isn’t carbon the main component of any biomass? So cheating again…

Third, Zn produced this way has do be heated with water steam to 350C to render hydrogen gas! How much energy that requires and where will it come from?

Scientifically speaking - total….

Walt in the burbs

The best place for algae energy growth, in the USA, is the Salton Sea.


The creation of the Salton Sea of today started in 1905, when heavy rainfall and snowmelt caused the Colorado River to swell, overrunning a set of headgates for the Alamo Canal. The resulting flood poured down the canal and breached an Imperial Valley dike, eroding two watercourses, the New River in the west, and the Alamo River in the east, each about 60 miles (97 km) long.[6] Over a period of approximately two years these two newly created rivers sporadically carried the entire volume of the Colorado River into the Salton Sink.[7]

The Southern Pacific Railroad attempted to stop the flooding by dumping earth into the headgates area, but the effort was not fast enough, and as the river eroded deeper and deeper into the dry desert sand of the Imperial Valley, a massive waterfall was created that started to cut rapidly upstream along the path of the Alamo Canal that now was occupied by the Colorado. This waterfall was initially 15 feet (4.6 m) high but grew to a height of 80 feet (24 m) before the flow through the breach was finally stopped. It was originally feared that the waterfall would recede upstream to the true main path of the Colorado, attaining a height of up to 100 to 300 feet (30 to 91 m), from where it would be practically impossible to fix the problem. As the basin filled, the town of Salton, a Southern Pacific Railroad siding and Torres-Martinez Indian land were submerged. The sudden influx of water and the lack of any drainage from the basin resulted in the formation of the Salton Sea.[8][9]

Environmental problems

The lack of an outflow means that the Salton Sea is a system of accelerated change. Variations in agricultural runoff cause fluctuations in water level (and flooding of surrounding communities in the 1950s and 1960s), and the relatively high salinity of the inflow feeding the Sea has resulted in ever increasing salinity. By the 1960s it was apparent that the salinity of the Salton Sea was rising, jeopardizing some of the species in it. The Salton Sea currently has a salinity exceeding 4.0% w/v (saltier than seawater) and many species of fish are no longer able to survive in the Salton. It is believed that once the salinity surpasses 4.4% w/v, only the tilapia will survive. Fertilizer runoff combined with the increasing salinity have resulted in large algal blooms and elevated bacteria levels.[1

So… The Salton Sea is essentially a product of crop run off from the highly productive Imperial Valley. Its full of fertilizer. Just what algae need.

The dept of energy says a modest algae bio-diesel system on the Salton Sea could provide enough bio-diesel to run the entire US truck fleet.

It would not need phosphate input past that already coming from the farm run off. In a sense it would be cleaning up and environmental disaster - the Salton Sea.


You’ve got the wrong end of the stick in relation to algae growth. The future doesn’t lie with algal biofuels. It lies with growth of algae for food supplements.

If you use organic wastes for your source nutrients (anaerobic digestion liquor is a good source), you can grow a lot of biomass per m3 of ground. On waste ground too - marginal land. Sure, there’s an energy cost of producing said bioreactors - but it isn’t as great as you would think - and to run them? You have a plastic matrix in a polytunnel, effectively. Most of the year all you need to run them is a small compressor to act as an air bubbler. Get a bit more integrated, and you can use waste heat from an industrial process, and possibly cleaned stack gas too.

What do you do with the algae? Well, at production rates of c. 2500 tonnes per Ha (in other words, a couple of orders of magnitude more than food crops) you have a high production rate. But it’s algae. What eats that?

The answer is simple. Fish do. The algal growth gives you ample fish feed. The fish you are feeding? Hardy omnivores such as tilapia or sturgeon. How do we farm fish at the moment? By farming solitary carniverous fish like trout or salmon together in huge concentrations by feeding them smaller fish that have been caught from the wild for this purpose. It makes no sense ecologically - look at the trophic levels.

But tilapia fed on algae? Grow very well, and are good eating.

Food waste -> AD for biogas -> digestate -> solid digestate as a compost to agricultural land, liquid digestate to algal growth. Algae grown to feed fish. Waste from fish and algae production fed back to AD plant. Waste heat and CO2 from biogas generation? To photobioreactor.

Pretty much all you need to grow fish at £10 per kg retail value in large numbers at next to no cost and a very good carbon outcome.

This is happening now, btw. It’s not a concept.



Your statement that you could not find any detail about how much brackish water can be found in desert areas is a bit troublesome. The southwest US has so much brackish water that it is difficult to drill to find fresh water, but not brackish water. New Mexico actually has a very large underground aquifer in the eastern part of the state. You do need to revisit this argument.

As new breeds of algae are discovered (and, yes, created), the amount of energy available in these organisms goes up. No, there is no perpetual energy system based on mechanics. No one said it had to be a closed loop. Sewerage exists everywhere, and can be a great source of food. Don’t close your mind to the future or new solutions because you love low/old tech. Change is inevitable.


I don’t mean to offend, Kris, but it’s easy to sit in an armchair and preach about this kind of thing. I recommend taking a look at Alcohol Can Be A Gas. It’s written by a permaculture expert who’s been in the ethanol (and sustainable farming) business since hippy times. He backs up all of his ideas with credible sources and proposes an elegant solution to ending the addiction to oil.

As far as algae production goes, I haven’t seen any diesel pumps that say that the fuel contains algae oil, whereas ethanol fuel was used in the U.S. in the early 1900’s and has been generated for centuries.

My own solution is disturbing but plausible with current technology. Vehicles would have a sealed (ala passenger jet blackbox) liquid flouride thorium reactor which would heat sealed water for a steam turbine. Efficiency wouldn’t be very relevant since the fuel source would last about a century. The reactor can’t go critical and the fuel cannot be used for weaponry. Since thorium is abundant in the U.S. and other countries, there’d be enough to last until the sun finally burns out on us. Of course, you could just make a thorium powerplant and generate hydrogen peroxide fuel for combustion engines. That works, too.

Again, I don’t mean to offend. I appreciate your articles, but there are times when high technology is very much appreciated. I’m not going to ride my bike in 20 Fahrenheit weather uphill to my school every day.


I’m a little late to the party but I have to say this. You might be right but I really hate the “don’t even try” attitude. We try things, we fail, we try something else. That’s how we learn and make progress.


This article does an excellent job of illustrating all of the challenges with algae and why it doesn’t appear ready for large scale use. With that said, it needs some inspiring thoughts on the future of biofuels, possibly from algae.

Algae (or switchgrass or other plants) can take CO2 and water and make fuel. Yes it takes nutrients to do that, but they are not used and can be RECYCLED for the next batch of fuel. They are not burned in the fuel as this article tries to imply with talk of phosphorus shortage and mining the ground of nutrients. It is up to us to figure out how to recycle those nutrients as efficiently as possible, maybe even without any energy input from non-renewables.

terry weir

Look at the chemistry in the biofuel energy cycle. Fertiliser elements such as Phosphorus and Pottassium are the equivalent of catalysts. They are essential to growing plants but are not part of the refined biodiesel or ethanol. ie they are a waste product of the conversion process. Therefore the opportunity to exists to recyle those elements as fertiliser for the next crop.

It is this management process which is essential for future sustainable agriculture or algae production.


This article was posted 2 yrs ago. What do you think about the scenario now, Kris?


Seems to me that no one fuel source, by itself, will magically solve all our problems. It will take several alternative energy sources, harnessed in areas where each is most abundant and practical, in order to ween ourselves off fossil fuels.

Growing algae WILL require energy. The question is, can that energy be provided on-site from a renewable resource? If windmills or solar panels can be used, what is the payback period and how much upfront investment will be required. If a portion of the energy produced will be used for the next batch, what percentage are we talking about?

Lots of questions need to be answered before we can evaluate whether this is the right fuel for the future, but not even trying because we’re afraid of what the results MIGHT be seems like a recipe for defeat before we even start.


So for any of you future folks still reading this page a long time from now, imagine this: using deep wells and chlorophyll-reduced algae rather than flat pools, and utilizing plastic bubbles to prevent contamination and reduce evaporation (all things mentioned by John earlier in comment 35 above) we flood the desert around Salton with seawater-irrigated algae farms.

Now, the thing no one seems to have mentioned about this system here so far is that pumping seawater to a below-sea-level area does NOT have to be energy intense. Any such system could operate under the same principle as a Pythagorean glass, wherein the gravitational energy difference is alone sufficient to pull the water down to irrigate the basin where the facilities are located.

And literally every inhabited continent has such a place: Death Valley and Salton in the US; Sechura in Peru; Lakes Eyre and Frome in Australia; the Dead and Caspian Seas in Eurasia; the Afar and Qattara Depressions in Africa. (If the Chinese irrigated Turfan with seawater, they would surely go down in history as one of the most audacious nations ever to exist.) Salton in particular (as Walt in the burbs said in comment 46 above) has huge amounts of agricultural runoff from the Imperial Valley; surely, using that runoff to power the tractors that farm it would make greater ecological/economic sense than letting those nutrients sit around underutilized?

Once we have algae, we refine the final oil product, extracting out useful minerals like phosphate and using that to refertilize the farms. (As terry weir mentioned in comment 52 above.)

Several such farms could be powered by a solar-thermal power plant; and I call them farms because if the world ever progresses to the point of having an overabundance of desert algae oil stations, this sort of infrastructure could be repurposed for aquaculture or hydroponics. (As Gwawdiwr mentioned in comment 47 above, algae could be an ideal way to produce food supplements, or could be used to feed fish like sturgeon and tilapia.)

In short, I see nothing wrong algae oil. The weird bit is the author’s insistence that we abstain from technology for its own sake, rather than for concrete benefits that low- or no-tech can give us in this particular arena. As this site has documented elsewhere, the great benefit of carbon-based fuels is that they help us work *faster*; phrase this another way, that we’re manufacturing time, and I would hold that high-tech solutions like biofuels serve a valid purpose in society… *as long as* their production is low-impact.


When im reading these articles I’m getting an idea that all we can do is consume less and everything will be fine. I know that the author wants to point at the other side of the medal of the emerging technologies but in my opinion we can’t go on with this kind of oil driven world.

My opinion on algae fuel is that firstly it is the technology that doesn’t change current infrastructure so everything that runs on oil can run on algae fuel too. Secondly it is carbon negative so to speak.

But imagine this: you built relatively cheap thorium plants for abundant of cheap electricity, you have closed system of algae production for eliminating contamination and disease control. Then you can build plants for desalination using bacteria, salt produced that way can be used as fertilizer. Scale that and put it in Libya, Somalia, India… Use thorium reactor driven oil tankers to ship algae oil around the world. Imagine connection of technologies, solar , wind, bacteria, thorium, tidal power, geopower….

Just imagine all these technologies working together

Michael Capponi

I am surprised. I have come to a point not very far into this article and seen something I hadn’t expected to see from this publication. I have read these articles for at least two years every now and then, and I normally would consider the thoughtfulness of the author(s) very thorough - I think this magazine elucidates so many of the little problems and inefficiencies embodied in a given high-tech solution that so many people gloss over. I think I have seen an example in this article where this characteristic thoroughness has been compromised.

“Now, there are places which are both close to the sea and have lots of sun. But chances are slim that they are as cheap and abandoned like deserts are.”

The author hasn’t provided any evidence to substantiate this notion, and in fact I know of an organisation whose mission is to use seawater in desert environments (not specifically for the production of algae and biofuels) and who estimate that there are many thousands of kilometres of desert coastline suitable for their work.

I would like to draw the author’s attention to atmospheric physicist Carl Hodges, who has founded the seawater foundation whose mission is to develop ‘seawater farming’, which is basically digging rivers of seawater that flow inland and irrigating crops of halophytes (salt loving plants) with a view to producing useful crops, sequestering carbon in poor soils and mitigating climate change. I find this prospect very exciting and welcome anyone to learn more about it with this 15 minute documentary:

The alarming part of this foible - the apparently incorrect assumption that most land with access to copious sun and seawater will have already been utilised by tourist developments - is that it hints at the possibility that the thoroughness one attributes to this publication is only to be found in examples where it supports the argument being put forward. Being imprecise and making uneducated guesses about factors that might contradict a given argument is a surefire way to lose credibility.

I am hoping that this example is a rarity, because it would a shame if the integrity of these articles was compromised by ideological blindness for the low technology options.

I am not saying that this article’s points are moot simply because there could conceivably be great access to desert coastlines for prospective algae farms and biofuel producers, but it is worth looking into. Perhaps reconsidering the access to desert coastlines WILL provide a reason to support certain production of algae biofuels. I’m not sure. I hope we can both look into it.


The reason that it took about 90 tons of prehistoric plants and algae to produce enough fuel to to drive 40km is because most internal combustion engines, even today, are less than 50% efficient.

Perhaps producing fuels out of algae could work better if used to run more efficient engines.

That said, we would use a lot less fossil fuel if the engines running on it were that efficient, and so adding less carbon. I don’t really see why we should do away with fossil fuels altogether.