Companies and entrepreneurs around the world have been scrambling to find new and innovative ways to generate energy without using polluting and irreplaceable fossil fuels. One company in the United Kingdom has hit upon an interesting energy source: potatoes.
2 Sisters Food Group, as the name should make clear, is not in the business of generating energy. They’re one of the largest food companies in the UK, with more than 40 plants that employ 23,000 people and generates a revenue of £3.4 billion per year. So while energy concerns are encompassed within 2 Sisters’ typical area of focus, when you have that kind of money to play around with, you can afford to get creative.
That’s where the potatoes come in.
Food factories typical generate an enormous amount of waste, and the company’s plant in Carlisle, Cumbria, England is no exception. The plant makes about 80 million ready-to-eat meals per year, with potatoes being a major ingredient in many of the dishes they produced, such as shepherd’s pies and mashed potatoes.
A few years ago, 2 Sisters decided to do something about their carbon footprint, and realized that rather than trashing their food waste, they could use it to generate energy. The Carlisle plant quickly stuck out as being an ideal test case for the new idea, as it had a steady and consistent supply of potato-based waste.
The company approached H2 Energy, a firm that specialized in the development of advanced bio-refineries. The two companies signed a £50 million deal in which H2 would build and install bio-refineries at 10 of 2 Sisters’ manufacturing facilities. There are also talks of ultimately installing bio-refineries at all 42 of 2 Sisters’ food factories in the UK and the rest of Europe.
The Carlisle bio-refinery is the first of the planned bio-reactors to go online, and will generate 3,500 MWh of electricity per year, and will also produce 5,000 MWh of steam-power, which will supply 20% of the plant’s total energy needs. To give you an idea of how much electricity that is, in 2010, the average Canadian household consumed about 11.9 megawatts of electricity annually. The annual electricity production of the Carlisle bio-reactor could supply all of the energy needs of 294 households for an entire year. If you lump the plant’s steam power into that figure, the bio-refinery could power 714 homes. The new Carlisle bio-reactor comes with an additional bonus: it will produce as much a 20,000 litres of water, which can be used by the plant in its various manufacturing processes.
2 Sisters hopes that when their project is fully completed, the company’s plants will produce more than 100,000 MWh of energy per year, cutting their carbon production by more than 35,000 tonnes.
The idea of using food byproducts to create energy is gaining traction elsewhere as well.
The concept of using food byproducts to generate electricity is one that other companies are now working on. London-based company Bio-bean is developing a process to turn coffee byproducts into biomass pellets and biodiesel. The company’s founder Arthur Kay was inspired to find a way of capturing the energy potential of coffee waste after learning that in London alone, coffee production factories produce 200,000 tonnes of waste material annually. And it turns out that coffee byproducts are particularly energetic–biomass pellets produced from coffee products produce 150% more energy than traditional wood-based pellets, which is part of the reason that the startup company is starting to attract interest from a number of investors.
And in Edinburgh, Scotland, a company called Celtic Renewables is working on a process for creating a fuel called biobutanol from waste products generated by the fermentation of whisky. It turns out that 90% of the output from whisky distilleries is comprised of two waste products: pot ale, and draff. Pot ale is the term for the residue left inside of stills, which is comprised of yeast, yeast waste, copper, and various carbohydrates and proteins. Draff is what remains of the barley grain-based mash, after the wort has been drained off. While draff has long been used has a feed for farm animals, pot ale has long been a liability, as the copper in it is toxic. Scotland makes a lot of whisky, and as a consequence, it makes a lot more draff and pot ale: every year, Scottish distilleries produce about 500,000 metric tonnes of draff, and 1.6 billion litres of pot ale.
Martin Tangney, a professor and the founder of Celtic Renewable, realized that all of this waste could be used to produce energy-rich fuel via a long-abandoned fermentation process that produces fuel that cars can run on. Back in 1915, a chemist named Chaim Weizmann patented a process called ABE (acetone-butanol-ethanol), which used a mash of maize and potatoes to produce the three useful products that make up the process’s name. While ABE was used for decades to produce fuel and acetone, it was abandoned after the ’50s due to the ready supply of traditional petroleum-based fuels and chemicals. Tangney realized that the process could be applied to whisky waste products to produce biobutanol, which contains 25% more energy than ethanol, the much more popular and well-known biofuel currently making headlines. Biobutanol can be used in unmodified petrol-based car engines, and can also be blended with other fuels like petrol, diesel, and biodiesel. Tangney believes that Scotland can become the home of a £60 million biofuels industry through the re-appropriation of the region’s whisky waste.
Concepts and companies like those described above have been popping up with increasing frequency during the last few years. It will be interesting to see how readily these new industries can compete with other green-friendly energy companies that currently produce energy using solar, wind, and hydro power.
