Jeff Davies, Davies Brothers Waste Management

The green system literally cooks the rubbish in giant ovens - bin bags full of waste are fed in, and clean metals and sterilised plastics emerge half an hour later.

The metals and plastics can be sold for recycling, leaving a fibrous by-product.

And Jeff Davies, from Davies Brothers, stressed the benefits of the system.

"We've got no omissions, and no future problems," he said.

"The system is absolutely the thing of the future," added Mr Davies.

The blocks can be sold for recycling

Vale of Glamorgan Council is already reprocessing waste at the plant, and other councils may follow suit.

The development comes after concerns over the disposal of waste at landfill sites and incineration plants across Wales.

In January, opponents of a �25m incinerator planned for Wrexham, north Wales, handed a petition, containing thousands of signatures, to Welsh Assembly Members and local council officers.

The proposal, by the Portuguese-based company HLC, was criticised by local people who say it could have massive health implications - including birth defects and infertility.

Unsuitable site

In south Wales, a landfill site at Nantygwyddon tip in the Rhondda was closed to household waste after a damning report into the site commissioned by the Welsh Assembly.

Its author David Purchon said the location of the Nantygwyddon tip above the village of Gelli was unsuitable for a landfill site.

He said it was too windy, too wet and too close to nearby homes.

Following this closure, the assembly has also been urged to investigate a second site, the Trecatti facility, at Dowlais near Merthyr Tydfil.

However, Biffa Waste Services, the company which operates the Trecatti tip, insisted it was a well-run and well managed site.