Here is another bit of my upcoming book:Ten Technologies to Save the World – Kicking the Fossil Fuel Habit. Here I argue that biofuels have promise, but only if developed in novel ways. Irrigating the Sahara and growing salt-tolerant plants could replace all of our oil – for a couple of trillion dollars.
Copyright©2009 Tom Rand, Eco Ten Publishing. All rights reserved. No part of this excerpt may be used or reproduced in any manner whatsoever without written permission.
Third Generation Fuels – Thinking about Limits
Second generation fuels - ethanol from cellulose – sound pretty good if it doesn’t compete with our food supply.Is there really a need to go further? Sure there is. According to Dennis Bushnell, chief scientist at NASA Langley Research, “there’s just not enough fresh water and arable land to produce enough biofuels to replace the petroleum.”[i] The problem is there isn’t enough existing land or plant growth to make any real dent in our energy supply[ii] – food production issues aside.
If we were to replace all U.S. petroleum with first- or second-generation biofuels from conventional crops like soy, it would require the use of more[iii] than the entire U.S. land mass. Even palm oil, which generates 20 times the amount of biofuel per acre, would require more than a third of the arable land – and palms don’t even grow in Kansas!
When the European Union first mandated that a percentage of diesel fuel must be biodiesel, it ignited a surge in deforestation of rain forest in Indonesia to make room for plantations of palm for palm oil production. The plan backfired. Deforestation causes a massive spike[iv] in greenhouse gases. The net result was a increase in carbon emissions, not a reduction.
When Richard Branson, of Virgin Atlantic, flew one of his planes on a mix of regular fuel and the oil from 150,000 coconuts, it was touted as a sustainable fuel. The problem comes when you count the coconuts. Analysts pointed out there are not enough coconuts in the world to service just Heathrow! To be fair, Branson did show the possibility of alternate fuels, and he is now looking into … fuel from algae.
We need to go one step further if biofuels are to contribute anything of significance. Three new sources look promising. Algae can be cultivated in tanks and farmed from seaweed in our oceans. Halophytes – plants that drink salt-water and can grow in unproductive deserts like the Sahara – won’t compete with food. Jatropha, a plant which can grow on marginal land and on top of regular crops without reducing yields, also holds promise.
Algae – The really ‘green’ oil.
Pond scum, sea-weed, green goop – the unappetizing slippery stuff is one of the most promising sources of biofuel. Squeeze out the oil for biodiesel, and break down the rest for ethanol. John Sheehan, at the U.S. National Renewable Energy Laboratory says “There is no other resource that comes even close in magnitude to the potential for making oil.”[v]
Harvested from the ocean, or grown in tanks on non-fertile land, they can be fed waste-water or even the emissions from smokestacks. These little balls of oil[vi] are harvested on a continual basis, and can produce more than forty times the fuel per acre than any other plant – up to 20,000 gallons per acre per year. In the right conditions, algae can double its volume overnight. The trick is to get the growing conditions right, and do it on a big scale.
How big? Solix is a company that’s been dabbling in algae-based fuels for years. Douglas Henston, CEO, says “If we were to replace all of the diesel that we use in the United States with an algae derivative, we could do it on an area of land that’s about one-half of 1 percent of the current farm land that we use now.” So it’s promising, but that’s one big pond – and we’re not talking about regular ponds here. These are high-tech, triangular-shaped aquariums called ‘photobioreactors’.
Algae can pack a double punch. Since algae can eat high concentrations of carbon dioxide, it can be fed straight from a conventional power plant. “Algae can take (carbon dioxide), eat it and produce algae–that’s a known fact”[vii], says Isaac Berzin of GreenFuel Technologies, a super-smart startup from Cambridge, MA, with ties to MIT. It was Berzin’s work at NASA that really gives GreenFuels an edge.
GreenFuels builds a ‘bioreactor’, which is a fine-tuned, turbo-charged artificial pond. The turbo-charging is done by feeding in carbon dioxide emissions from a power plant. The algae is fine-tuned by using a cell culture unit originally developed to grow organisms for NASA’s micro-gravity space experiments. Feed in water and emissions samples, and just the right algae is grown to optimize production. The idea is to surround power plants with thousands of bioreactors. GreenFuels’ pilot plant will produce fuel for local buses.
Halophytes – Farming the Desert
Halophytes are plants that love salt water. So here’s an idea – irrigate vast swaths of desert with salt-water, and grow plants for biofuels. This may not yet be happening on a commercial scale, but the idea is sound and some high-powered thinkers are getting behind it. Dennis Bushnell, chief scientist at NASA’s Langley Research Center says “This is a revolution for agriculture as well as for energy.”[viii]
What’s the potential of halophytes? Well, according to Bushnell, the Sahara desert could by itself provide 94% of world energy consumption[ix] if it were converted to halophyte biofuel production. This may sound crazy – but these are the sorts of ideas that we need to take a really close look at. It was probably once thought absurd to go to the moon, or cross the ocean, or split the atom!
Jatropha – Between the Cracks
Jatropha is a plant that grows an inedible seed that is ideal for biodiesel. What makes the plant really promising is that it can be grown on crappy land that’s no good for crops, and in amongst existing crops without lowering the yield. It’s kind of like fuel for free when mixed with other crops. It’s promising enough that the Government of India has singled the plant out for a national push for biofuels.
Potentials and pitfalls
Clearly, biofuel has a role to play. Already some European countries generate up to 20% of their energy needs from biomass, mainly from burning waste for heat and electricity.
If biofuels are to play a more significant role, it will be in replacing our liquid fuels, used mainly for transportation. To replace more than a few percent of our petroleum use, though, biofuels must stop competing with our food crops for arable land, water and fertilizer. To get really serious, we must even get past using wood and inedible farm waste and other cellulosic sources.
The problems associated with cellulosic ethanol are two-fold: limited biomass supply and the dangers associated with the required genetic engineering. There just aren’t enough wood chips and plant stalks, and even if there were – engineering those tiny little self-reproducing microbes, like bacteria, is risky. There is always a danger of introducing new bugs that upset our delicately balanced ecology.
To really replace petroleum, biofuels must come from the sorts of third generation fuels outlined above – mainly algae and halophytes. Biofuel is no magic bullet. Only if the efforts we’ve made in finding and defending our sources of oil were matched by efforts to build vast fields of bioreactors fed by our existing carbon emissions, and vast tracts of desert land irrigated by salt water, could biofuels really change the game.
Trillion Dollar Question:
What do we get for a trillion dollars? If we were to use that money to irrigate the Sahara for halotrophe farming, and build biodiesel factories to process the plants, we’d be able to irrigate enough land[x] and build enough processing capacity to replace about half of the total world oil supply.
[ii] Every source of plant growth added together, all over the world, is six times our total energy use (Source: G. Boyle, pg. 107). That’s all the crops – food and waste, all the weeds, all the forests, all the plankton in the oceans – everything. Even if we could make use of a faction of that biomass, the conversion to useful energy would be a small fraction of that. Say we could somehow make use of 5% of the total global biomass production – which seems wildly optimistic – and we get a 33% conversion rate (also optimistic), that represents less than 12% of our energy use.
[iii] Take soy production of 0.4 tonnes, or 125 gallons, per hectare. The entire U.S. landmass is 930 million hectares, giving a theoretical maximum of 119 billion gallons of biofuel. It would take 140.8 billion gallons of biofuel to replace U.S. petroleum. That’s more than the U.S. land mass. Palm oil production, which generates 20 times the amount of biofuel per hectare, would require about 7 % of the landmass. Since only 19% of the landmass is arable, that’s more than a third of the arable land mass.
[v] Source: Pond-Powered Biofuels: Turning Algae into America’s New Energy, Popular Mechanics, March 29, 2007. The National Renewable Energy Laboratory had a program looking into algae for energy, until the Bush administration shut it down.
[ix] From the conclusion of the paper HALOPHYTES ENERGY FEEDSTOCKS: BACK TO OUR ROOTS, by R.C. Hendricks, D.M. Bushnell, “As an example, if the Sahara desert (8.6×108 ha) were made capable to support halophyte agriculture … and if production were increased to 100 bbl/ha-yr of bio-oil, it alone would supply 421.4 Q, or94% of the 2004 world energy consumption”.
[x] Irrigating the Desert: According to Wynne Thorne, “Agricultural Production in Irrigated Areas”, in Arid Lands in Transition, Harold E. Dregne, editor, AAAS (1970) pp. 31-56: The weighted average for medium to large irrigation projects is around $98,000 per sq. km. This ranges between $56,000-$177,000 per sq. km. These are 1970 prices, so let’s triple the median to around $300,000. This is for land that doesn’t need clearing, but it’s also for land to which you need to supply fresh, not salt, water. So a trillion dollars might convert more than three million sq. km to irrigated land. Since the Sahara is about 9,000,000 sq. km, and that could provide almost all our energy needs, the 3 million figure corresponds to a third of our energy needs. But oil is only a third of that, so it could replace roughly all of our oil consumption.
Converting the Fuel: According to the U.S. Energy Information Administration (http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/ ) , “A new biodiesel plant is estimated to cost $1.04 per annual gallon of capacity.” So the same trillion could build factories that could produce 23 billion barrels of bio-oil a year. That’s pretty close to what we use now.
Putting it Together: So to irrigate the land, and to process the oil, it would take 2 trillion dollars to replace all our oil. So a trillion dollars would replace half.