The December 2022 issue of IEEE Spectrum is here!

Close bar

U.K.’s Trash Becomes Biofuel Treasure

Supermarkets in the United Kingdom are turning their food waste into biofuel and savings

2 min read
U.K.’s Trash Becomes Biofuel Treasure

Efforts to turn waste into energy are increasing around world, and booming in the United Kingdom. Supermarkets especially are investing in biogas technologies, or at least shipping their waste to renewable energy plants, according to a Bloomberg report.

Government subsidies and requirements play a part in encouraging the purchase of clean energy, but so do the hefty landfill taxes. The U.K. garbage tax, which was £64 (about US $100) per ton in April, increases by £8 every year. For the large supermarket chains, that fee adds up, as do their heavy energy bills. Executives agree that reducing energy costs is just good business, and that means renewable energy—and the government energy credits that go with it.

The Renewable Obligation program requires utilities to buy a certain amount of electricity from clean sources. The program issues certificates for each megawatt-hour produced from renewable sources. If a utility company doesn’t get enough Renewable Obligation Certificates, it must pay a penalty. Different techs get different credits, with anaerobic digestion getting two.

Anaerobic digestion turns organic material into biogas by breaking down the substance in an oxygen-free environment. For supermarkets burdened with food waste, it’s an irresistible option. Experiments with leftovers—fish heads, rotisserie chicken fats, lamb chops, rotting vegetables, sandwich breads—are taking place across the U.K. Market chains are also exploring and using solar panels, wood chips, and geothermal power. And the demonstrated financial benefits are spurring the construction of new power plants.

Tesco saves £200 million a year. Marks & Spencer saved £70 million last year. And Wal-Mart’s Asda expects to save £800 million by 2020. Sainsbury’s plans to build 40 waste-to-energy electricity plants in the next five years.

With the increasing costs of sending trash to landfills, shipping it to bioenergy plants makes tremendous sense. Government predictions state that bioenergy could supply at least 8 percent of the U.K.’s demand by 2020.

But investments and benefits are not limited to one country. Worldwide, companies have invested about $18.2 billion in waste energy technology. In North America it's the trash haulers. In Brazil, incinerators are being built. French and Dutch airlines are running planes on cooking oil. And a Brazilian airline is even testing sugarcane as a fuel

Photo: Courtesy Ze-gen, Waste Gasification Goes Commercial

The Conversation (0)
This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

Keep Reading ↓Show less