Sewage - The Fuel of the Future?

Waste not want not.

Monopolistic water and sewage companies rarely get a good press but here is a fascinating news story in the Times. Severn Trent, one of the UK’s largest water suppliers which supplies water and waste services to 3.3 million households is researching ways in which the hundreds of thousands of sewage sludge that is generated every year in the UK can be turned into a biomass fuel to produce heat and electricity. The economic incentives to consider this have been boosted by a combination of subsidy, taxation and regulation.

On the subsidy front, since 2003, Renewables Obligation Certificates — a form of subsidy to accredited generators — have been available for electricity that is generated by burning biomass fuels, which include wood, straw or sewage gas and sludge.

On the tax side - the government has gradually increased the size of the landfill tax which covers disposal of waste in landfill sites - the tax is set to increase by 20 per cent to £40 per tonne, up from £32 in 2008. In 2010 it is set to rise again to £48 per tonne.

Regulations now ban the disposal of sewage sludge at sea.

The Times reports that

“About 347,000km of sewers collect more than 11billion litres of waste water in the UK every day. This water is treated at about 9,000 sewage treatment works across the country. Roughly 62 per cent of the country’s sludge is treated and recycled into a type of fertiliser known as biosolids, which is used to fertilise more than 80,000 hectares of British farming land every year.”

This is a good example to use in exam questions because the incentives to develop innovative schemes to find economically viable forms of renewable energy often require a combination of policies working in tandem rather than a single ‘big bang’ approach. Government policies towards waste can be found here.