Select Committee on Welsh Affairs Written Evidence

Written Evidence from Francis John Golden

  The above Inquiry is focusing on the cost, cleanliness, efficiency and sustainability of existing energy sources in Wales. In addition to consider the merits of newer forms of energy provision.

  One source of energy that has not been exploited at all in Wales and could be considered as a "newer form of energy provision" is msw—municipal solid waste.

  *The calorific value of coal is 28Gj per tonne, that of rdf: refuse-derived fuel (dried msw after metals, minerals and hard plastics extracted for recycling) is about 20 Gj per tonne. By comparison oil is 46Gj per tonne and nearly all plastic about 39Gj. LNG is about 40Gj per tonne.

*Environment Agency—Energy content of materials. 2005

  The past custom of landfilling msw and plastic is shewn as a considerable waste of what should be recoverable energy from a sustainable source.

  Recognising that recovery of this energy by incineration is not welcome due to concern about emissions and the intrinsic inefficiency of mass burning, several engineering companies** developed more efficient and environmentally benign thermal solutions, viz. pyrolysis and gasification.

**Of these only Compact Power and GEM, with UK patented technologies, remain

  To encourage development of these the then Energy Minister Mr Wilson in 2002 brought in the RO (Renewable Obligation) adding that the UK had lost out on the engineering opportunities offered by North Sea oil in the 1970s and did not want to make this mistake again.

  Apart from plant and forestry fuel that could be incinerated, the RO was and is restricted to non-fossil fuel derived waste converted by the Advanced Conversion Technological processes of pyrolysis, gasification and anaerobic digestion. It was therefore announced that processes creating energy from non-fossil fuel derived waste utilising ACT (Advanced Conversion Technology) would be entitled to a ROC (Renewable Obligation Certificate) for every MW generated. Each would have an initial value of £30, but would escalate each year to guarantee a return on capital invested and establish a new, British industry.

   MSW is a heterogeneous waste. Picking and mechanical extraction processes can recover the cans, glass, plastic containers and minerals, but no process can completely extract the remnants of plastic film: that is still entrained in the residue.

  To full entitlement to ROCs the UK Regulations require that no more than 2% (of plastic) by calorific value can be entrained. That is virtually impossible to achieve. That is now being recognised by the DTI in the Renewable Obligation consultation and consideration is being given to extending this to 10%. Ireland appears to be going in this direction as well, but is giving thought to having the entrained plastic be measured by weight rather than calorific value.

  The original initiative by the DTI has, to all intents and purposes, failed to live up to expectations. The imposition of the 2% "contamination" limit of MSW has in fact restricted the RO (in respect of waste) to biomass only and done nothing to divert waste away from the landfill.

  The two companies remaining are:

  Graveson Energy Management, ie GEM:— pyrolysis, ie air is excluded and the prepared fuel is "flash" converted at about 820o. There is no need for a tall stack. Dioxins and furans are not created.

  Compact Power:— pyrolysis, gasification and incineration (to burn off the emissions).

  All the other companies have ceased or dormant.

  (There are other companies now in play, they are claimed to be starved air, ie gasification, but are they little more than incineration,?).

  In three years there has been little progress.

  Compact Power has recently been granted planning consent for a 25,000 tonne demonstration plant at Bristol.

  GEM has planning consent in a major poultry firm in Norwich: a plant using chicken litter as fuel to generate in the first phase 2/3 Mwh of electricity and the same in useable heat, then in the second phase 10 to 12 Mwh plus the same in useable heat. Also, enabled with a DEFRA grant, a demonstration plant to treat 25,000 tonnes of prepared msw is likely at a site near Scarborough.

  To date Compact Power received £3,000 in state aid and spent £20 million and has an operating plant at Avonmouth treating hospital waste.

  Graveson Energy Management, GEM, Romsey has had no state aid, but spent at least £8 million and a 1/3size pilot plant operating at Romsey since 1999.

  Handicaps to development are:

    —  Procurement procedures for local authorities not stipulating ACT.

    —  Uncertainty about "new" technology.

    —  Banks require contract in place. LAs will give this only if funds are in place, ergo, little movement away from landfill.

    —  Financial incentive of the ROC not achieveable for the above reasons.

    —  Major waste operators own landfills.

    —  The application of the Waste Incineration Directive to a pure pyrolysis process like GEM where there is "incineration" only in the reciprocating engine powering the generator.

  The 2004 DEFRA scheme to provide support funding to ten applications involves incredible expense to the applicants while changing the conditions so that any support funding will not be for initial construct, when these companies really need it, but rather to the running once its built. The awards already given seem to have gone to the tried and tested rather than genuinely innovative British technology.

  GEM is intending to make a planning application in Wales. The site in question has road and rail links. Prepared msw, with mechanical pre-sorting and drying preferably at LA facilities would be converted and 50,000tonnes would deliver eight to 11 Mwhe plus the same in useable heat to the grid. The ash, at about 10% could be incorporated into concrete blocks (similar to well known thermolite blocks from main power stations) and nothing going to landfill sites.

  Once up and running it will make a significant impact on the waste diversion and renewable energy scene. At that stage then consideration could be given to stripping off the hydrogen from the synthetic gas for research into road or other use.

  In the Waste Strategy composting is frequently the preferred option for green and non-fossil fuel derived waste. The residue or fibre produced by these MBT, aerobic and anaerobic patent processes is likely to be spread as cover on landfill. There it decomposes and produces methane. One tonne of which is equivalent to 20 tonnes of CO2. It is better to reduce these emissions rather than increase them. The residue when dried down to about 5% moisture would be an excellent fuel for the GEM pyrolysis process. So would the hospital plastic that is currently sterilised then put to landfill.

  Pyrolysis is the most efficient of the three thermal technologies. If all the waste going to landfill in Wales was prepared as fuel for GEM converters most of the energy problems would have a solution. Accompanied by recycling, most of the landfill diversion problems would be solved as well.


    —  1.  UK Gov. policy

        If each landfill or civic amenity site had a waste fuel preparation and GEM power station connected, that would provide a continuous rather than intermittent (wind) source of green electricity. This would make the balancing needed by the grid that much controllable and reliable.

    —  2.  More delegation to Wales could ensure that Wales' Local Authorities be encouraged to direct that waste be prepared for utilisation as a fuel for ACT.

    —  3.  The current portfolio has no provision for ACT generated electricity. Ensuring that that was included could make a major addition to the future portfolio.

29 November 2005

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