Archive for the ‘Uncategorized’ Category

BARD Algae, Revisited
May 29, 2011

BARD refuses to bow down to the laws of physics!

BARD remains defiant!

Well, it seems that there are enough potential algae investors who have not read my blog that money continues to flow to such ventures as a company that claims that they will produce 8,571,428 gallons of algae oil per acre annually, then when challenged, up their projection to 20,000,000 gallons!

Could these investors be seeing something we are not?

There’s a problem here, and it’s called physics.

Firstly, understand that the energy in 20,000,000 gallons/acre/year vastly outstrips the energy striking an acre in a year.  But BARD claims that they obtain their fantastical yields using artificial lighting, allowing them to outstrip merely stellar fusion-based systems.

But due to fundamental limitations in the physics of photosynthetic molecule interacting it is simply impossible to get more than 11% conversion of light energy to chemical energy, and then taking into account the fact that cells have to produce many things besides oil just to live, even under ideal circumstances no more than 5% has been observed in practice.

So could it ever make sense to take 100 MW and converting it into, at best, 5 MW of fuel production?

Let’s hear from you, the readers, and delve a little deeper…

More soon,



The Chronicle Profiles Your Humble Author
July 25, 2010

The San Francisco Chronicle published a nice profile of yours truly, written by Alice Chen.  Read it if you’d like to know more about the author…

BTW here are some more pictures from the article

Best, Aaron

Algae Energy Analysis, or You Do The Math: The Clarens Paper
February 8, 2010

Instead of getting into algae economics right away, I am in this post responding to a current event of interest…

The algae cycle? from

The headline sure looks bad: “Engineers Find Significant Environmental Impacts With Algae-Based Biofuel.”  The New York Times, U.S. News and World Report, and Science Daily all join the hue and cry:

“The U.Va. research, just published in the journal Environmental Science & Technology, demonstrates that algae production consumes more energy, has higher greenhouse gas emissions and uses more water than other biofuel sources, such as switchgrass, canola and corn.”

Algae has been sold on its green-ness, so this is a stab at the very heart of the nascent industry.  The Algae Biofuel Association fired back the next day, pointing out that much of the data used by the study was from the 70’s and 80’s, and that newer algaculture techniques invalidate the numbers they used.
Now, I have no doubt that new technology will improve algae biofuel’s carbon footprint.  But having read the paper and the online supporting materials, I don’t think that simply invoking the promise of new technology really gets at what the paper was about.

I’d like to do that here.

Part 1:
Is a pile of sticks really the same as a tank of gas?

The authors open their paper with a premise that wipes many of algae’s advantages off the map at the outset.  They declare that they will compare algae to corn ethanol, soy biodiesel, and switchgrass ethanol on a purely energy basis, including the stalks and leaves as equal in value to the starch and oil portions that are currently used for fuel.  Now, plants make their structure out of materials evolutionarily designed to be resistant to breakdown — cellulose, hemicellulose, and lignin — and so making it into fuel requires highly specialized, finicky organisms, or high temperatures to decompose these tough compounds.  All this requires a lot of infrastructure, and a lot of energy (which is why it takes about as much energy as is in corn ethanol to make it), as does gathering up and chopping up plant materials until they are digestible chunks sitting in a bin in a biorefinery.

Algae are a very different picture, and this is one of the main reasons for all the interest in them.   Their biomass can be over 50% vegetable oil (compared to 2-3% for typical conventional oil crops), which can be pumped and pipelined to a standard refinery and transformed with conventional, low-energy methods into gasoline, diesel, and jet-fuel equivalents.    Uncle Joe can also make it into biodiesel in his garage with minimal inputs or even know-how. Try doing that with a pile of damp switchgrass.

But this is a minor objection compared to what the authors did next.

Part 2:
These algae are made for recycling, and that’s just what they’ll do

From the headline, one might assume that the excessive energy use claimed arises from the operations of the algae farm — paddlewheels, centrifuges, and such — after all, it seems like a higher-tech form of farming, involving more gear — but a quick glance at the energy breakdown shows that something altogether different is going on.  In fact, over 97% of the claimed water use and 94% of the energy use arises from the manufacture of fertilizer, CO2, and other chemicals.  Now the technology for synthetic fertilizer (the Haber-Bosch process) was originally developed for explosives, so it should come as no surprise that their manufacture consumes a lot of energy.  That the authors take this into account is valid in theory, but they make an assumption that runs against the most basic economic considerations of algae farming — that the farmers, after extracting the lipid fraction of their algal harvest, will inexplicably burn the remaining fraction for the meager heating value retained therein, then throw the nutrient-rich ash into a landfill.  Assuming that the algae farmer has even a lick of sense, she’ll put those nutrients back into the pond.  The ability to recycle nutrients almost completely is one of the great advantages of algae farming over traditional farming.

Nutrient recycling, plus the use of exhaust for CO2 (which every biofuel algae farmer I’ve ever met intends to do), profoundly changes the analysis, and in fact reverses the result that was trumpeted across all the headlines.  With 100% nutrient recycle, using the authors’ numbers, algae biofuels come out well ahead of corn, canola, and switchgrass, even using the authors’ approach of equating haybales and barrels.  With 95% nutrient recycle, algae still comes out on top of all comers except a slight loss to switchgrass on water use.  This is comparing apples to oranges, though, as switchgrass requires scarce fresh water, and algae can grow in salt- and waste-water.

Part 3:
The Land will have the last word.

The authors chose to ignore the greenhouse gas impacts of indirect land-use changes, which can be a hundred times greater than the annual emissions thought to be saved by land crop-based biofuels, and really, IMO, should rule out any land crop-based biofuel not grown on truly marginal land.  Algae do not use arable land, and so avoid this impact as well as competition with food production.


So a little digging reveals that the media’s presentation of the results of this paper are entirely misleading.  I do agree with the authors regarding the advantages of the use of wastewater (the NASA project I’m working on is designed to use wastewaster for nutrients and exhaust for CO2), and as far as source-separated urine as an algae nutrient source goes, this has been a favorite research area of mine (bottom line: it works great!), so we don’t disagree about everything.

But it’s hard to overlook the fact that a result so contrary to the algae industry’s founding notions is music to the ears of some in the ethanol crowd, who are beginning to feel some competition from algae for the title of “fuel of the future”.

P.S. If you wonder about my qualifications to evaluate the quality of another scientist’s energy analysis, please take a look at my recent paper comparing energy use in organic farming to that of conventional methods, (here’s a link to a pdf of my slides) in unprecedented detail (which turns out to be pretty important).  I have also written a consulting report on biofuel energy balances, so I feel qualified to say that these guys are way off the mark, for reasons much more fundamental than those cited by the ABO.

But I encourage you all to look at the paper itself, and to give comments and feedback.  Thanks!

Sub-Prime Algae Companies
January 12, 2010

One of the fastest ways to tell if a company is legit is to check their claims against basic laws of physics, chemistry, etc.  In the algae world, a company’s predictions of how many gallons of biofuel they can generate per acre per year is a good place to start.  Obviously, there’s a temptation to exaggerate to generate interest, so it tells you a lot about a company where they put this number.  For example, our friend GreenFuel said they would generate 15,000 gallons, to the derision of at least one major algae scientist. It’s also good to know the limits on photosynthesis in any case.

At the 2008 Algae Biomass Summit in Seattle, I saw an excellent presentation entitled “Theoretical Maximum Algae Oil Production,” by Kristina Weyer of Solix Biofuels.  The details of the analysis are somewhat complicated, but the basic idea is straightforward.  Algae, like all plants, convert the energy of the sun into chemical energy, some of which we can take and use as fuel energy.  So you’re limited by the amount of sunlight reaching the location of your algae farm, and by the efficiency with which the algae convert that sunlight energy into usable fuel energy.  The former is determined mainly by location, varying by about 2x between the highest tropical/desert zones and the temperate parts of the U.S. and Europe.  Only 45.8% of solar radiation is usable by plants (though there are some odd algae capable of using infra-red or ultraviolet light, and fungi capable of absorbing energy from nuclear radiation…sorry I’m getting carried away).

The efficiency of algae in making fuel varies much more, and can be to some extent improved by engineering.  It depends on five basic factors, all of which apply equally to open ponds and even the cleverest of photobioreactors:

  1. Light transmission efficiency, or what fraction of the light actually makes it into the culture; this is determined by the reflectivity of the surface of the pond or photo-bioreactor, and any absorption from dirt or algae clinging to the inside of the PBR.  In a well-designed, well-maintained system, this loss might be 10%.
  2. Photon absorption efficiency, a combination of the efficiency with which the algae’s photosynthetic molecules convert the electromagnetic photon energy into chemical energy, and the rate at which this chemical energy can be passed to the reaction center, where it is stored by cleaving a CO2 molecule.  The conversion efficiency is always less than 100% because the photochemical molecules only capture a specific amount of energy from each photon, wasting a sizable amount of energy from higher-energy photons.  This is an impossible-to-avoid 24% loss.  The capturing of photons and passing them to reaction centers is performed by a constantly-shifting ensemble of generally colorful molecules unique to each type of algae (giving them a wide range of colors, from pale yellow to blood red to purple-black).  Each time the photonic energy is passed from one molecule to another, some energy is lost.  Excess photons can also disrupt the process of passing the energy along, so efficiency drops with increased light level.  Many groups are working on fixing this problem with genetic engineering; the Aquatic Species Program final report estimated that a 3x improvement in photosynthetic efficiency over wild algae should be possible through antenna mutants, though this much improvement has not yet been demonstrated.  We’ll talk more about this stuff later.  Since we’re interested in ultimate possible efficiencies here, we’ll assume that you’ve engineered or bred the heck out of your algae, and gotten the loss due to all these mechanisms to a fantastic level of 50% (90% loss is not unusual for wild algae in direct sunlight…).
  3. Fundamental photosynthesis quantum efficiency, or the number of photons that have to make it through all the previously-mentioned processes to break up one CO2 molecule and make “biomass” (i.e., a simple sugar building block).  In the process, about 73% of the photonic energy is lost.  There is no fix for this, barring the creation of a wholly new photosynthetic pathway, which is *way* beyond current bioengineering technology.
  4. Biomass accumulation efficiency, or the losses incurred in the cell’s metabolism converting the simple sugar from the last step into  actual, living biomass, and energy used up by the algae just living, especially at night (because algae don’t own the night™).  40% loss is a typical number, and there aren’t many ideas for how to improve this, because algae are, after all, living, squidgy things, and burn calories just like we do.
  5. Lipid percentage, or what fraction of the biomass is actual oil.  Up to 70% has been obtained in labs, but in practice, consistently getting 50% oil would be a great achievement.

Combining these very optimistic assumptions with actual weather data gives a maximum output of 6,500 gallons per acre per year for an extremely sunny place like Phoenix, Arizona.  Anyone claiming more than this should be looked at with real skepticism.

If you throw any sense of realism to the winds, and assume that light transmission, photon absorption efficiency, and biomass accumulation efficiency are all 100% — in effect, assuming a science-fiction organism that does nothing but make oil, with absolutely no internal losses, and no metabolism at all, with the maximum possible 70% oil content, growing at a fictional spot on the equator where there are never any clouds, you’d get a fantasy yield of 53,000 gallons of oil per acre per year.

So how come Valcent, Inc. is claiming they can generate 100,000 gallons of fuel per acre per year?

Valcent and their Vertigro system (pictured above) are prominently featured on the YouTube and many “green energy” sites, and have appeared on CNN and other TV shows, in every case to breathless enthusiasm.  Apparently, no one thought to do the back-of-the-envelope calculation that would show that they are expecting us to swallow a claim that is simply absurd.

But they are not alone.

Joule Biotechnologies says that their genetically engineered photosynthetic mini-beasts are not algae, but the above argument applies to any photosynthetic organism, so their claim that they will be producing 25,000 gallons of ethanol and 15,000 gallons of diesel per acre per year should be a red flag for investors (not to mention that they are claiming they’ll have a pilot plant in on year, and commercial-scale production by 2012!).  The fact that the organisms (which may be a type of mini-duckweed) are secreting the fuel instead of being harvested and processed changes the above calculation somewhat, but not enough.  If the critters can be kept alive indefinitely producing the product, then the lipid fraction is effectively 100%.  This still does not get you close to their claims for any realistic biological photosynthetic mechanism.  Caveat emptor!

But the real clowns of the algae biofuel world have to be BARD — Biofuel Advance Research and Development, winner of an “Algaeprenuer 2009″ award from the National Algae Association:

“BARD’s closed loop photo-bioreactor technology can produce 66 million gallon of algae oil in 7 acres of land,
which is 8,571,428 gallon of algae oil per acre. The pilot facility will begin by producing 43,070 gallons of algae oil / biodiesel per annum using only six modules of photo-bioreactors covering 84 square feet.”

This was a bit much, and got them some heat from some quarters.  In reply to their critics, CEO Surajit Khanna wrote the following:

“Why you or your other folks are comparing our numbers from our technology to open pond based algae technology? Completely bogus. We are not even talking here about open pond nor using sunlight. Because you all don’t know what this means so you are challenging our figures.

[Whether] you or your people believe in our technology or not – how does that matter to BARD? We are not seeking any funding from you nor seeking any help. Why would the public care about your comments? We don’t have to prove to you anything. Just for your information our data is based on our proven lab scale technology. Our scientist has been working on this technology since 1957. The same lab scale [has] been transformed to pilot-plant scale.”

To which, Eric Wesoff of Greentech Media makes the point that “if their scientist has been working on this since 1957, he’ll need to work fast to see the results of his efforts.”

To help out this poor scientist, I have done my best to envision what this fantabulous facility would look like:

And it would be extra cool because it would glow like crazy at night, using the entire energy of at least three large coal-fired power plants.

(Optional calculation proving above statement: (146MJ/gal * 66Mgal)/(365*24*3600) = 300MW; at a high light-to-biofuel efficiency of 10%, this would mean 3GW of light from the LEDs.  1GJ is a typical value for a regional coal-fired plant in the U.S.)

I guess the $40M they claim to have raised is just a down payment.

It’s kind of sad that they’re building it in Ohio, where such a monument to the human capacity to achieve untold gallons per acre would not get many visitors.

As a last, lovely touch, when this story first broke, the last time I tried to visit their website my browser warned me that it was attempting to install malware on my computer (luckily, I use a scriptblocker).    Infer what you will.

So, are there any legitimate algae companies?  Well, there are many that don’t require new laws of physics to reach their projected yields.  The smart ones are focusing on the real issue of algae biofuel — the economics.

Next: Is it possible make $$$ growing algae for biofuel?

P.S. I always like it when people posting use numbers to justify their arguments, even if I don’t agree, and even if it’s not particularly informed.  Check this recent assessment of the energy balance of algae biofuels, esp. the comments 😉

Post 1: The Algae Boom (Bubble?)
January 7, 2010

So, these days, even the average grocery clerk has heard the hooplah about algae biofuels and wants to know if this is really going to solve the end-of-oil problem.  This is a very new phenomenon.  When I first started working on algae biofuels in 2006, the Google filter I set up to find news about algae brought back 95% stories about the dangers of algae blooms (more ‘bout that later), and how to kill algae — precious little about algae farming.

That has changed, in a major way.  Now, every time one turns around, there’s a new, heavily-funded algae play.  Billions of $$$ are being pumped down a global algae biofuels R&D pipeline.  Everyone from governments (e.g. DARPA and DOE, and now NASA) to giant corporations (see Exxon’s $600M), to small-scale DIY-ers (like my are throwing their hats into the ring.


Well, before we launch off into peak oil, etc., let’s look at fundamentals.  For those new to this, algae are microscopic plants that float in water.  Through the natural process of photosynthesis, which algae perform at higher rates than land plants because of their small size, algae produce more than half of all the oxygen we breath, and remove a corresponding amount of carbon from the atmosphere, an amount far exceeding what we humans produce.  Despite being microscopic, algae blooms are frequently visible from outer space, can annihilate huge ecosystems, and even threaten to stop the Olympics.

There is much more to say about algae as they exist on our planet already – their astonishing diversity and ancientness, for example, but given their sheer mass and reproductive capability it would seem natural to want to redirect this to human profit, as we have with their multicelled brethren.  And recent events – related to the exhaustion of current approaches to agriculture and fuel production — have kicked development of algae farming into high gear.  Triple-digit oil prices have motivated a global drive to find renewable replacements for fossil fuels – i.e., biofuels – creating a demand for agricultural output that far outstrips what land crops could ever provide, given available arable land and fresh water.

Which brings us to the main bullet points of any algae biofuel production pitch:

  1. Algae don’t need arable land, any special kind of land, or even land at all – they can be grown in deserts, or on the surface of the ocean;
  2. Algae don’t need fresh water – they can be grown in salt water, or in saline ground water, and especially love waste water, i.e. sewage;
  3. Algae are extremely productive on a per-area basis, producing more biomass per area than land crops;
  4. Algae can convert over 50% of their biomass into oil, far more than the few percent of land crops, so their per-area oil production is 100x or more of typical current oil-generating crops;
  5. Algae can clean up waste water, efficiently removing nutrients that would otherwise pollute the environment;
  6. Algae can clean up carbon dioxide and smog-forming nitrogen oxides from industrial exhaust sources such as power plants;
  7. Algae can produce a wide range of products from biofuels to nutraceuticals, fertilizers, chemical precursors, etc.

Algae are also astonishingly diverse, and incredibly ancient, dating back to near the origin of life.  Referring to “algae” as a group is almost a misnomer, as the evolutionary-genetic expanse of micro-algae is vast.  Pick two algae, even two that look identical under the microscope, and they may be no more closely related than you are to a fungus, or even further apart.  It has been about three and half billion years since the first cyanobacterium emerged from the primordial ooze — for organisms that reproduce daily, this means a trillion or more generations — compared to a measly hundred thousand or so separating us from Australopithicus.  Add to this the huge range of organisms that have engulfed algae to take advantage of their photosynthetic apparati (and who were often engulfed in turn), and even the algae who have lost their chlorophyll to live off of chemicals and other creatures, and “algae” becomes a term so wide it almost loses meaning.

What this means, practically, is that algae grow anywhere there is water, sunshine, and CO2, producing a dizzying array of possible products.  This fact is beginning to be reflected in the diversity of algae companies — from Solazyme and Martek, growing milky yellow algae on sugar in the dark, to Aurora Biofuels, Seambiotic, LiveFuels, and many others using open ponds to make fuel from exhaust in the sun, to AlgaTech growing bright red algae in tubes in Israel, making an antioxidant worth more per gram than Colombian nose candy.  And this is just scratching the surface.

But for now, everyone is focused on one potential algae product — fuel.

Algae Biofuel — What the Fuss is All About (for now)

So, fuel.  Well, it’s no secret that oil is running out (though we may argue about the timing), or that the extraction and consumption of fossil fuels cause a great deal of harm to people and the global environment.  Triple-digit oil prices have triggered a run on alternative fuels, mostly made from land crops, but since the vast majority of potential farmland is already in use or consists of vital ecosystems, this can’t be done on a large scale without tragic consequences for food markets and the few remaining intact ecosystems, not to mention limited water resources, increased demand for fossil fuel-based fertilizers, more agricultural pollution, etc…
In rides algae to the rescue!

Such was the slogan of algae pioneer GreenFuel Technologies.  Founded in 2001, with MIT roots, GF jumped into the algae ring years before the “algae boom” — in fact, in some ways, they launched it.

By 2004, GreenFuel had a row of triangular acrylic tube photobioreactors capturing carbon dioxide and NOx from the exhaust of a power plant on the MIT campus.  They made wild claims as to the yield of algae that would be attainable, obtained $20M from a top-flight Wall Street venture capital company, and were fundamentally ‘powned by Australian physics graduate student Krassen Dimitrov, who proved using the most basic assumptions that GreenFuel’s bioreactors could never turn a profit.  (We will go into this analysis, and its limitations, soon.) They were also publicly mocked by veteran algae biofuel researcher John Benneman.

GreenFuel fired back at its critics, rebutting Dimitrov, and legally threatening Dr. Benneman.  And the fundamental disdain which they showed toward basic physics and economics did not prevent them from getting further funding.  But reality ultimately caught up with them; in mid-2007, they fired half their staff, and in 2009, they went out of business, but not before they managed to get involved in a mafia-linked scam in South Africa.  $70M+ down the drain.

Losing money on alternative energy technologies is nothing new.  But have we learned anything?  Are people giving money to current algae co’s showing GreenFuel-like signs?

And what was this “Reality” that GreenFuels ran up against?

Next: Sub-Prime Algae Companies!