Welcome
The benefits of desilting are self explanatory, what is not always known is the extent of those benefits. Servicing, maintenance, developing, desilting, however you describe it, the effects can be related back to global issues in the field of landfilling as well as ongoing commercial benefits.
2020 Vision!!
The recent White Paper on Energy revised and reiterated their binding targets for Renewable Energy and reducing greenhouse gas emissions. They agreed that 20% of the EU's energy was to be from renewable sources by the year 2020. Latest data shows that the current total energy mix for renewable energy is around 4%, of which landfill gas accounts for 25 - 60% of this value (depending on whose figures you use).
The proposed banding regime puts landfill gas in the lowest banding. Therefore the level of financial support may be capped until 2013. In addition to meeting the 2020 figures they will also have to account for the potential loss of 22.5GW of existing power from power stations that may close by 2020.
The huge resource pool that is available from landfill gas will diminish over time and therefore the availability of this contributing towards renewables will subsequently reduce. Particularly as the White Paper on Waste is also intending to ensure that waste to landfill is reduced by up to 60% over the next 10 years. In addition the mix of waste landfilled will also affect the proportions of useable gas. One goal of the 2003 Energy paper is "to maintain the reliability of energy supplies". Renewable energy from landfilling is unlikely, with the strategies given, to be a long term supply for the UK. Therefore maintenance of existing infrastructure and exploiting the available gas over the next 20 years is critical to ensuring that contribution to renewable energy as well as commercial benefits can be achieved.
RENEWable or REUSEable?
On numerous occasions we have undertaken desilting works on gas wells across the UK. The benefits in this are the increase in the available headspace hence maximising the gas extraction and efficiency of the gas engines. Recently a site had around 14 gas wells desilted and this resulted in a drop of suction from 120mb to 40mb. This has been sustained following the works. Benefits include commercial as well as compliance. Although running of gas engines at lower suction will invariably have an impact on the running costs as well as the corresponding gas flow figures.
Approximate budget costs for this particular project indicated costs of £100 per well as opposed to the alternative which was retrodrilling, these can be from £1000 upwards. Where possible regular maintenance of all wells can and has continued to provide economical and compliance benefits to all sectors with a commitment to landfill. These wells were over 7 years old and are still able to provide the necessary infrastructure for current gas engine onerous requirements. With the implications identified in the Energy and Waste White Papers it is likely that the costs and taxes applicable to landfilling will continue to increase indefinitely. Re use of existing infrastructure makes good financial sense.
Rubbish - Good or Bad?
Waste again is identified as being 'bad' as well as the process of landfilling. Statistics for carbon footprints of different renewable energy sources still identify emissions with coal being the greatest and gas being the least. In a world where money dictates the application of technology not the environment, it is clear that combined strategies of waste, energy and applications available, now and in the future, should be adequately reviewed. Falling into line, whilst very important, sometimes creates bigger monsters than there were previously. Landfilling of waste although not technically advanced as bioreactors and pyrolysis as a disposal point for waste, does create a safe controlled method of disposal and will do well into the 21st Century. Management of gas and the ROC's ensures that private finance is rewarded. Planning for wind farms, is not proving easy to obtain nationally although assistance for this has been promised both in R & D and financially through renewable obligation schemes. These larger schemes will have lead in times of up to 5 to 10 years through planning, construction and commissioning stages. The importance of landfill gas should not be overlooked, which may occur if the Waste White Paper pursues the non descript method of minimising disposal to landfill. Landfill gas is produced due to the biological breakdown of different waste components removing specific waste streams affects the materials being broken down and consequently affects the production quality and reuse of the gas.
The scale of waste produced is as a result of modern society - people should be less critical of the processes, landfilling in particular, and more aware of the pivotal effect this process has on decision making.