Methane galore on whisky island

Distillery waste will be converted into gas to help make Islay self-sufficient in green energy.
Jonathan Leake

Energy from whisky? Lovers of the amber spirit may think it sounds like the environment movement’s worst-ever idea but the Scottish island of Islay is pioneering a system that uses whisky to create green energy.
Bruichladdich Distillery is to build an anaerobic digester to convert thousands of tons of yeasty waste into methane gas, which will be burned to make electricity.
Islay is home to some of Scotland’s best-known whiskies. Seven other distilleries on the island — Ardbeg, Laphroaig, Lagavulin, Bowmore, Caol Ila, Bunnahabhain and Kilchoman — are understood to be considering similar schemes.
If the idea is a success, the distilleries could end up generating much of the island’s electricity and may even have enough gas left over to power vehicles.
Mark Reynier, the owner of Bruichladdich Distillery, said: “We are going to install two anaerobic digesters on our site where the waste will be broken down to produce biogas, which can then be burnt to make electricity. In theory, it could meet all our power needs.”
The first digester will be installed next month. The innovation is driven by several factors. One is the whisky industry’s growing concern over its product’s carbon footprint, thought to be one of the highest for any food or drink.
None of the main distillers will release figures but the process of distilling alone is highly energy intensive. Added to this is the fact that most whisky is exported in heavy bottles and elaborate packaging.
On Islay, there is also the environmental impact of the many tons of distillery waste, which is disposed of in the sea each week. A pipeline carries this waste to the Sound of Islay.
Reynier, whose plant produces 46,000 12-bottle cases a year, spends £20,000 a year simply on ferrying waste in tankers from his distillery to the pipeline terminal. The anaerobic digestion system should remove this cost as well as supplying 80% of the power the distillery requires, currently costing £36,000 a year. These savings will be augmented by government subsidies for renewable power generation.
Reynier said: “The digesters will cost about £300,000 in capital outlay so it should take just three to five years to recoup the cost.”
He hopes to use such innovation to help market Bruichladdich as one of the greenest whiskies. “Whisky has a very high carbon footprint,” said Reynier. “We have already cut it by using locally grown and organic barley rather than importing it, and these digesters will bring it down further.” Indeed, Diageo, the drinks giant, has invested in a similar scheme at its Cameronbridge distillery.
There are other reasons for the distilleries’ interest in the technology. Islay has an antiquated power supply based on a single cable from the mainland, and voltage fluctuations exacerbated by the distilleries’ demands can cause problems with computers and other electronic equipment. Generating power on the island would help reduce this problem.
Anaerobic digestion works by allowing bacteria to break down organic waste without oxygen. This means the bacteria cannot digest the waste completely so, instead of just producing carbon dioxide they produce methane, the main constituent of natural gas.
Such systems have been known for a long time but initially they were industrial-scale installations based on huge “reactor tanks”. The waste has to be collected and brought to them, and it then takes about 30 days for bacteria to break down a single large tankful of waste. This makes such systems impractical for most small businesses. In recent years, however, systems have been developed that have reduced the size of the reactor tanks, and this allows a single tank to be processed in a matter of hours.
Bruichladdich’s system is being built by Biowayste, a Northamptonshire firm that has installed five such plants, including at Muntons, a brewing company in Suffolk, and at Orchard House Foods in Northamptonshire. It has eight others in the pipeline or under construction.
Barry Howard, chairman of Biowayste, said: “There are 5,000 small food manufacturers around Britain, all generating waste material and then paying to get rid of it. We can take that waste and turn it into electricity on their own sites, saving them money on waste disposal and power. We can also use the system to generate heat for their factories.”
The green nature of the power and the capture of the heat makes such systems lucrative. Each megawatt hour of power attracts two government renewables obligation certificates, one for the power and one for the re-use of the heat. These can be sold for a profit to other companies needing to offset their pollution.
Howard believes that Islay is ideally placed to benefit from the technology. “The whisky distillers are increasingly aware of their environmental impact, so if we can prove our systems at Bruichladdich work, I hope we will get the other seven distilleries interested, too.”
The project will delight Islay’s environmental movement, which is strongly supported by the 3,200-strong population on the south Hebridean island. There is already a wave-power system near Portnahaven, which supplies electricity for the island’s grid. Islay Energy Trust and Scottish Power Renewables have plans for 10 tidal turbines fixed to the seabed in the Sound of Islay. This is a tidal race where the currents are strong and therefore ideal for generating power.
David Protherough, project manager at Re-jig (Recycle — Jura/Islay Group), said the distillery project would help to cut tanker traffic on the island’s roads and also reduce marine pollution. “We have spoken to the managers of the distilleries on the island and they are keen. Our hope is that the distilleries will make so much biogas that there will be enough to power some of the island’s vehicles too.
“If you put it all together with the wave and tidal power systems, Islay could be one of the greenest communities in Britain,” said Protherough.