The ultimate green solution to our energy needs may be right beneath our feet, but at what cost to Scotland, asks Peter Jones
If YOU have paving or walls which get damp, you will be familiar with the green slimy stuff which tends to grow on it. Underfoot, it is a damn nuisance as it can turn your nice patio or stone steps into a slippery leg-break trap. But it could, ridiculous as it sounds, be something that could help save the world, even if it might have a distinct downside for the Scottish economy.
Algae are little tiny plant organisms and, like all plants, they produce substances called lipids, naturally occurring molecules which have the function of storing energy. Some lipids come in the form of oil which can be extracted. Getting oil out of plants such as palm and rape has been known about for centuries. Using oil produced this way as a fuel, however, is prohibitively expensive. Algae could change all that.
Algae have always been an attractive idea for fuel production because they bypass a big problem with using plants to produce combustible hydrocarbons. The more land you use for biofuels, such as getting ethanol from maize, the less there is for food production.
This isn’t great, especially at times like now when drought is ravaging the American mid-west and slashing the US harvest to such an extent that America is having to import large quantities of grain. More expensive bread and other foods will be the consequence, so producing lots of biofuel this way is not a great idea.
Algae are another matter altogether. You can grow them in places that are, like your paving slabs, hostile to any other plant. They don’t need fresh water. Some thrive in salt or brackish water that not even animals drink. So algae farms can be put on salty marshes or arid lands next to the sea, which are useless for agriculture.
And because algae don’t have roots and stems which need energy to sustain, they can store up huge quantities of oil-bearing lipids.
According to one 2010 study by researchers at Southampton University and the Indian Institute of Petroleum, corn is the least efficient producer of oil, yielding 70 litres per acre. Rapeseed does better, producing 480 litres per acre while the oil palm yields an impressive 2,400 litres.
Algae, however, put them all in the shade, being capable of producing, depending on the variety, between 23,500 and 55,000 litres of oil per acre. They have two other big advantages. The first is that they thrive on pollution. Many of the nutrients algae chiefly need – nitrogen, potassium, and phosphorus – can come from sewage. And secondly they need lots of carbon dioxide which they pull out of the atmosphere. Add in sunlight, and you have all you need for lots of algae.
Brilliant. We can make use of one pollutant, plus the gas which is warming the planet to life-threatening levels, and produce fuel for our vehicles. And since the carbon dioxide effluent that such fuel produces is drawn from the atmosphere rather than from deep underground, algae-based biofuel is just as sustainable as a wood-burning stove.
So what is there not to like about biofuels from algae and why aren’t we doing it on a grand scale?
Experiments in algae-based biofuels first began in the 1970s when scientists rapidly encountered a problem. When algae store lots of energy in the form of oil, they don’t grow very fast, and when they do grow fast, they don’t make a lot of oil. This research was stimulated by the big increase in conventional oil prices during that decade, but interest waned when oil prices fell.
Now that oil prices are high again, interest in algae has returned, but this time scientists know all about genetic modification. Much research is going into manipulating their genes so that the organism is tricked into producing more oil. Even more is being spent in finding and identifying all the 200,000 algae species reckoned to exist to see if there are some undiscovered ones which are especially efficient at oil production.
Even more experimentation is being done into the best way of growing algae. Open ponds seem the obvious way, but they are prone to being contaminated with algae you don’t want. Plus, when you get an algae growth on the surface, it blocks sunlight from penetrating deeper, reducing overall growth.
It now seems certainly possible to get about 23,000 litres from an acre of algae farm per year, and this figure could rise to about 38,000 litres. At that upper scale of production, the US Department of Energy theorises that it would be possible to grow all the oil that American vehicles annually consume from an area equivalent to half the state of Maine, or about 0.4 per cent of the US land mass.
The problem now becomes the cost. It is hard to get a fix on what the actual costs of current algae oil production is. The American military is an enthusiastic experimenter with biofuels and has in the recent past paid for large quantities of algafuel costing between $133 and $425 per gallon, which is clearly ridiculously expensive.
All sorts of claims of breakthroughs by many companies have been made, but few have so far looked plausible. Nonetheless, the Pentagon’s Defence Advanced Research Projects Agency, which both finances and monitors research into algae fuels, says it has now managed to produce algafuel for $2 per gallon and that it will produce jet aircraft quality algafuel for $3 per gallon by 2013.
The advances that have been made in cracking the scientific, production, and cost problems are remarkable. A huge amount of money is now being invested all over the world, particularly in India and China, to try and come up with a commercially viable algafuel. Exxon, which once denounced the whole concept as drivel, announced in 2009 that it was going to devote $600 million to researching it.
The question now looks as though it is not if, but when this can be achieved. And when it does happen, the rush to adopt it will be a stampede. Oil production which is environmentally sustainable, and which costs less than dragging out the unsustainable stuff from under the sea? Who won’t be wanting that?
Cheap sustainable energy will be good news for the world economy and for climate change. But it won’t be good news for the North Sea oil industry, nor for the tax revenues that come from it, nor indeed for Scottish hopes of building a carbon capture and storage industry.