As global warming is increasing remorselessly, various options are being tried. Generating electricity from garbage is one such. The methane route seems attractive for many.
About 45 minutes north of downtown Los Angeles, a machine the size of a small truck flattens tons of food scraps, paper towels and other household trash into the side of a growing 300-foot pile.
To Waste Management, which operates the landfill, this is more than just a mountain of garbage. Pipes tunneled deep into the mound extract gas from the rotting waste and send it to a plant that turns it into electricity.
Apart from the huge-wheeled compactor driving over garbage on its surface, it looks like an ordinary hillside. And it doesn't even smell. Yet it produces enough energy to power 2,500 homes in Southern California.
Trash, rubbish, whatever you call it, the 1.6 billion tonnes of stuff the world throws away each year 250 kilograms per person is being touted as a big potential source of clean energy, Reuters reports.
As concerns about climate change escalate and prices on fossil fuels like oil and natural gas soar to record levels, more companies are investing in ways to use methane gas to power homes and vehicles.
Around the world, landfills where municipal waste is collected and buried are one of the biggest producers of methane, a gas whose greenhouse effect is 21 times worse than carbon dioxide. If instead that gas is collected and burned to generate electricity, proponents say the resulting emissions of carbon dioxide are less harmful to the environment than the original methane. In the United States, trash haulers like Waste Management and Allied Waste Industries Inc are rapidly expanding the number of gas-to-energy projects at their landfills, while start-up companies are developing the latest technologies to transform garbage into ethanol, gas and electricity.
"We are able to take that resource and turn it into real value financially for us. In a very basic sense it helps improve our earnings," said Ted Neura, senior director of renewable energy development for Phoenix-based Allied Waste, which is turning waste into energy at 54 of its 169 U.S. landfills, with 16 more projects in the works.
The "green" credentials that go along with the waste-to-energy projects are an added benefit, Neura said.
"You begin to look at landfills a little differently when you couple them with a renewable energy project," he said.