A project entry from Kerala that converts food waste into cooking gas has been nominated among the winners of the Ashden Awards for Sustainable Energy, while another Indian entry, from Solar Electric Light Company (Selco), which provides affordable solar power systems to the poor, received an outstanding achievement award for companies.

The Kerala-based Biotech has succeeded in tackling the problem of the dumping of food waste in the streets of Kerala through the installation of biogas plants that use the food waste to produce gas for cooking and, in some cases, electricity for lighting; the residue serves as a fertiliser.

To date Biotech has built and installed an impressive 12,000 domestic plants (160 of which also use human waste from toilets to avoid contamination of ground water), 220 institutional plants and 17 municipal plants that use waste from markets to power generators.

The disposal of food waste and the production of clean energy are not the only benefits of Biotech''s scheme. The plants also replace the equivalent of about 3.7 tonnes / day of LPG and diesel which in turn results in the saving of about 3,700 tonnes / year of CO2, with further savings from the reduction in methane production as a result of the uncontrolled decomposition of waste, and from the transport of LPG.

The Ashden Trust, one of the Sainsbury family charitable trusts, instituted the Ashden Awards in 2001.

Also on the list were a Chinese entry for a stove fuelled by crop waste, affordable solar power projects from Laos and Tanzania, and a solar energy boat project from Bangladesh.

Each won a prize of £30,000 pounds in the five international categories of the Ashden Awards for Sustainable Energy, while Selco received of £15,000 pounds for an Indian company.

The Ashden Awards reward and promote excellence in local sustainable energy solutions in the UK and developing countries. "Our winners show how sustainable energy can improve health, education and livelihoods and at the same time reduce carbon emissions," said Sarah Butler-Sloss, who headed the judging panel.

"If these technologies were expanded and replicated on a large scale, they would play a significant role in helping us to tackle climate change and poverty. What we need now is the political will to scale up and roll out these solutions."

They are awarded each year to deserving projects that can benefit local communities and also be expanded to boost sustainable development.

The five international categories are enterprise, food security, light and power, education and welfare, and Africa.

• China''s Beijing Shenzhou Daxu Bio-Energy Technology Company Ltd won the enterprise award
  
• India''s Biotech won food security
  
• Sunlabob Renewable Energies Ltd of Laos won light and power
  
• Bangladesh''s Shidhulai Swanirvar Sangstha won the education award and
  
• Tanzania''s Zara Solar Ltd won the Africa award