This issue of Energy is themed, with energy from waste as the subject. This is an area that should concern all of us for a number of reasons, the most important being the level of waste being generated and our end use of it (landfilling, recycling, composting or incinerating) to release its energy.
There is considerable growth in such countries as China and India and an insatiable desire for both energy and products in the developed countries, including the UK. This is such that the need to import energy is very much with us. With this come the issues of security of supply and the need to make use of available indigenous resources (Griffiths and Williams, 2006). With this growth in energy and products comes ever-increasing waste. For instance, in the UK alone, there was an increase in municipal solid waste (MSW), per capita, of over 18% between 1995 (499 kg) and 2001 (590 kg) (Eurostat, 2004). Of the 590 kg/capita in 2001, 80% was sent to landfill. If the growth trend continues, there is the potential for the amount of waste generated to double by 2020. This raises the question of whether or not recycling, reusing, etc., will be capable of meeting the problem. Probably not! This issue and the massive increases in the landfill tax, mean there is a need for alternative solutions, such as thermal treatment processes, to be utilised. Griffiths and Williams (2007) state that a typical calorific value for MSW, in the UK, is around 10 GJ/t which, if converted into electricity (with approximately 20% efficiency), will yield around 550 kWh/t of MSW. This efficiency could be as high as 40% with suitable sorting and conditioning of the MSW could provide a crucial source of power generation at a local level and go some way to meeting the EU landfill directive.
The content in this issue of Energy opens with a useful insight into a landfill plant in South Africa where the author gives a short overview of a project to develop a site under the clean development mechanism (Pearson, 2010). This project’s aim is to extract landfill gas and combust it, destroying the major constituent, methane. As well as reducing the greenhouse gas and earning certified emission reduction credits, with expansion the project will produce up to 6.5 MWe. This process is being supported by the South African government in the form of tariff changes.
Following the look at a South African initiative is a strong trio of publications on a UK development, the Sheffield energy recovery facility (SERF). It begins with a briefing which provides readers with an easy-to-read introduction into the methodology, procedures and practices (with an emphasis on the UK position) used for ‘extracting’ energy from waste (Stephens, 2010). This provides a particularly good backdrop to the rest of the papers in the issue and gives the reader a view of the bigger picture with the EU’s directive on landfill, waste incineration and energy from renewable sources.
With the scene set, the second of the SERF papers outlines the pre-construction process that brought the facility into being (Stephens and Duval, 2010). The reasoning behind the facility is provided along with the very practical issues that arise during the design, tendering and construction phases of such a facility that has to meet a number of legislations and directives at both national and international levels. As the paper implies, it will be of great interest to those who are likely to be going through the same process for the first time. This provides an insight into the difficulties and risks associated with such a project, and how a Limited Liability Partnership can successfully operate as a team to achieve the final aim.
To finish off this trio of papers, Kirkman et al. (2010) give an overview of the first year of operation of the SERF from 2006. This shows the potential for this sort of facility to meet the upper limits (~40%) of converting waste to energy. This is also discussed in relation to the vital data, that of the facilities emissions.
This issue of Energy finishes with a look at the policy and institutional issues associated with waste to energy in the UK (Jamasb et al., 2010). The authors discuss the fact that since there are differences in public opinion and, in fact, the choice in available technology, a harmonised waste management policy needs to be put in place. They also suggest that the development of energy from waste plants would be put on a level playing field as other renewable energy sources if the government was to make it eligible for renewable obligation certificates. They also point out that the UK still has a way to go with the need for an efficient heat delivery network.
