The influential House of Commons Public Affairs Committee has pointed out that the UK is falling behind in its efforts to meet the 1999 EU directive to cut the amount of biodegradable waste going to landfill.

The 18.1 million tonnes we dumped in 2003/4 needs to be reduced to 13.7 million by 2010. By 2013 the figure needs to be 9.2 million and by 2020, only 6.3 million. While encouraging the public to recycle and compost more is a part of the solution, building new waste to energy plants is the main action required.

The Public Accounts Committee recognises the main obstacle to new builds is that public opinion is against them on the NIMBY (not in my back yard) principle and is suggesting waste to energy planning needs to be fast tracked if the targets are to be met.

This will obviously help, but another significant problem is with the waste to energy industry itself that appears loath to invest in more publicly acceptable new and high specification technology that will eat into their significant profit margins. This, in theory, is when the fine system kicks in.

When a country does not meet its agreed targets the European Commission levies a fine. In the UK this will effectively be paid by those County Councils who fail to achieve their individual targets. Collectively, their fine could be as high as £180 million a year. This figure must surely focus the minds of the county council officers charged with awarding future contracts for waste disposal.

70 million tonnes of carbon emissions per year come from industrial and commercial waste streams and those originating from the food industry account for 10% of this total.  The latest regulations designed to reduce the amount of landfill are becoming progressively onerous and will have encouraged companies to focus attention on ways to reduce their liabilities.  One way will be by converting part of this waste into energy.

The waste streams themselves will to a large extent determine whether it is more efficient to incinerate and create heat or to process waste to produce fuel capable of being used in a separate waste to energy facility. 

Clearly, the cost of a waste to energy facility, whether for incineration or fuel production, is significant and few companies can afford it unless their waste stream is large enough to justify the expense. However, given the size of the problem, companies might consider working together sharing both the cost of the facility and the profits to be made on the resulting energy sales such as electricity to the grid.

The issues to be dealt with for this to become a commercial reality will include more companies appointing specific waste to energy managers to evaluate their needs and link them to specific technologies. Companies in the same industries are likely to have similar waste streams and trade associations are an obvious means of bringing them together.

Landfill is a major issue. Every EU member state needs to reduce its landfill volumes to 50% of its 1995 level by 2009 and to 35% by 2016. As many local authorities struggle to meet the UK governments target for reducing their landfill tonnage over the next decade (and with a fine of £150 for every tonne over their preset limit this task is one most authorities are focusing on) the point should not be lost that ever more effective recycling must remain critical to the process. As Friends of the Earth have pointed out, far more energy is saved through recycling than can be recovered via energy generated from incineration or anaerobic digestion.

However, once all that can be recycled has been separated out from the rest, the question for each local authority is whether to adopt incineration or an alternative, such as a dry waste solution, involving anaerobic digestion. 

Modern thermal technology (also known as incineration or energy for waste) burns waste in highly efficient furnaces or boilers that can produce steam and/or electricity. The negative of this method of converting waste to energy is that between 15% and

25% by weight of the original waste remains as fly ash or bottom ash and has to be disposed of in a hazardous waste designated landfill.

One alternative to incineration is to use a bio-drying plant to create dry waste that can be used for energy generation. 

This bio-drying process takes place in an entirely sealed unit. The waste is initially placed into a pool under compression for 12 to 15 days to allow micro organisms to grow and consume the most easily digested components. This produces heat allowing the water content to evaporate, reducing the weight of the waste by a third. (the water vapour is purified by passing through a biological filter that absorbs and degrades volatile and smelly components). The resulting dry waste is totally odourless and is then fed into a refining section that will separate out ferrous and non ferrous metals for recycling. It then separates the remaining waste into two fractions. The first, known as methanogenic, has a low calorific value but is capable of producing biogas.  To create biogas, the methanogenic fraction is fed into one of the cells of a biogas reactor. The cell is sealed, water is added to activate an anaerobic fermentation process and the biogas produced will fuel engines coupled with generators to produce electricity.

The second fraction, known as combustible or refined RDF (refuse derived fuel), has a high calorific content (20,000 kj / kg) and is used as a secondary fuel for electricity generation or for powering industrial processes such as cement production plants.

The costs for the different processes are similar, as is the energy generated. For the local authority planner it is a matter of you pay your money and you take your choice.