HOWZAT

The digestor is essentially a large steel stomach. It speeds up the natural breakdown of waste from years to a matter of days by feeding it into an oxygen-starved environment infested with microbes. The process generates a mixture of carbon dioxide and methane, which is burnt to generate heat and electricity. The digestate, the substance that is left, is sold as a type of super-manure for local cereal farms and the heat is piped to a nearby immigrant detention centre.

“This is a win-win-win,” said Christiansen. “It’s green as hell. It saves us a chunk of money, and we can set up that link with the digestate for our suppliers.”

Sainsbury has been so encouraged by the programme that last month it announced plans to build five food-to-energy sites around the country over the next two years. Christiansen expects the digestors to shave an estimated £2m off the company’s annual £9m disposal bill. When they are all up and running, they could be a money maker, with Sainsbury selling surplus power to the grid.

Every year, the food industry produces about 17m tonnes of landfill waste, a quarter of the nation’s total. Because most of it is organic, the opportunity to convert it to fuel is higher than with typical municipal waste, which requires sorting.

Inetec, a small Welsh firm, thinks it has an answer. The company has devised a system that grinds up food and packaging material into a mixture that can be burnt in a converted biomass boiler to generate electricity. Greggs, the baker, Northern Foods and Greencore have all agreed to send their food waste to a new £100m facility that Inetec hopes to build near the docks at Immingham on the Humber. “Instead of woodchips or other biomass, we will be burning food waste. It will be the first plant of its nature almost in the world,” said contracts administrator Gareth Nicholas.

It could be, but at the moment the plant is stuck on the drawing board. Inetec has been struggling for more than a year to find financial backers. As at many companies that are trying to get novel projects off the ground, finding financing from banks that are themselves having financial problems is difficult.

“In the current climate, the banks aren’t lending. They want very safe investments, like schools or hospitals,” said Rob Dustan, environmental business development director at VT Group, best known for its military and shipbuilding work. “When you say you want to build a plant to process waste with a new technology, it’s very hard to persuade them.”

But there are several reasons why companies are beginning to throw their weight behind the shift. For one, being seen as more green than your rivals has become important. Consumers are much more conscious than they were even a year ago about the environmental credentials of the companies they use.

The government is also pushing the issue because reducing the amount of landfill methane — which is 21 times more powerful a greenhouse gas than carbon dioxide — will help it to reach its targets for reducing pollution. The Tories have latched on to waste and recycling as a key issue, proposing a system that would give monthly payments to households that recycle. The government boasts that recycling levels reached 34% this year, up from 8% a decade ago. But that is still well below the European average of more than 50% of total waste.

Britain’s approach is “much less advanced than in most of Europe”, said John Edwards, a partner at the Augusta & Co merchant bank. “Only Greece sends proportionately more waste to landfill than the UK.”

The real driver for change, however, is cost. Ten years ago, landfilling was still cheap, maybe £10 a tonne. Today it is about £70 a tonne. The cost has been pushed up by the government’s “landfill tax escalator” — it rises £8 a tonne every year — and by the increased cost of engineering landfills so that they comply with stricter environmental regulations. According to the Audit Commission, Britain could run out of landfill capacity within seven years anyway.

For a company like Sainsbury, it’s a bearable cost. But for smaller firms and, more importantly, local authorities, which are saddled with handling more of the country’s waste than any other group, it’s painful. According to Dustan at VT, 18 projects from councils will be put out to tender in the coming months.

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