26 November 2012
WYG’s Waste Management Team, in collaboration with long-standing UK client, Hastings Borough Council, is currently working with Local Government in Sierra Leone on a low tech, low cost biogas solution which could bring significant environmental and health benefits throughout Africa and the third world. The project is headed by Richard Homewood (Director of Environmental Services at Hastings Borough Council), who has quickly formed an effective and successful partnership with Kevin Monson, Anaerobic Digestion (AD) specialist at WYG.
The potential for this relatively straightforward approach to limiting methane emissions is huge, given that over half the world’s population lives in the tropics, where wastes management is poor, and wood and charcoal are the cooking fuels of choice. The project is attracting attention from the United Nations Development Programme, the UK Department for International Development, and many other national and international bodies with an interest in environmental, energy, wastes, and soil improvement developments.
If the pilot project proves successful and follow-up funding is secured, similar initiatives will be rolled out across Sierra Leone and other tropical territories.
Funded by the Commonwealth Local Government Forum (CLGF), the original brief in September 2011 was for Hastings Borough Council to provide wastes management expertise to Local Governments in Sierra Leone by presenting at the ‘Building capacity for effective waste management in Sierra Leone’, Good Practice Scheme National Dissemination Workshop’ in Freetown. WYG was invited to attend this event as wastes consultants by Hastings Borough Council. This collaborative approach resulted in a number of recommendations including community composting, battery bins and household scale biogas digesters.
In February 2012, again in partnership with Hastings Borough Council, Monson designed and oversaw construction, and operator training of four demonstration scale biogas digesters in Hastings Village, and was subsequently invited to return to Sierra Leone in October 2012 to oversee the construction and operator training on a further five domestic scale biogas units in addition to evaluating a number of other wastes management initiatives. Both the February and October 2012 projects were undertaken in partnership, managed by Hastings Borough Council, funded by the CLGF, with technical expertise provided by WYG.
Sierra Leone, like much of the developing world, suffers from poor wastes management and energy infrastructure, high energy costs (in relation to GDP), and poor environmental and soil management. Wood or charcoal are used in over 80 per cent of cooking, accelerating deforestation and soil erosion and, with repeated daily exposure, leading to respiratory diseases and shortened life expectancy in women.
Over 90 per cent of households in rural areas grow their own vegetables, and a wastes audit showed that more than three quarters of household waste was biodegradable. Local Government rarely has funding to collect wastes, leading to uncontrolled roadside dumping. This pointed to home composting or Anaerobic Digestion (AD) as potential solutions. For food wastes, AD offers advantages in that the process is totally enclosed, reducing pest access, and the biogas produced can be used for cooking, offsetting the use of wood and charcoal. As well as important cost and health benefits for the consumer, AD reduces the rate of deforestation, allows the digestate to be put to crops (improving soil quality by recycling nutrients and organics), saves CO2 emissions and reduces uncontrolled methane emissions.
The team combined and simplified the best elements of earlier units, to design a physically and biologically robust micro AD unit. The new design, with the exception of the biogas stoves and fittings which need to be imported, represents a ‘back to basics’ AD plant that can be built and repaired cheaply from locally available materials, with WYG providing the training to enable this.
The units continue to work well, accepting chopped kitchen wastes and spoiled fruit and vegetables, and providing enough biogas for cooking several times a day. These small-scale systems also save villagers money that would otherwise be spent on wood and charcoal. Trials continue to further quantify costs and benefits, and build on the practical lessons learned by those using the units on a day-to-day basis.
For more information, please contact:
Louise Gardner, PR & Communications Executive
T: +44 (0)113 219 2242