United Utilities' scheme in partnership with the National Grid to use anaerobic digestion to produce biogas at its Davyhulme sewage treatment works for grid injection and vehicle fuel has been dropped after Xebec, the preferred specialist technology supplier, withdrew from the UK market. The resulting delay to the project meant it could not benefit from a grant from the Government’s Waste & Resources Action Programme (Wrap).
The new demonstration plant would have been the first large scale biomethane gas to grid injection system in the UK which would allowed a comparison of the relative efficiency and cost effectiveness of the three main uses for biogas – CHP, gas grid injection and vehicle fuel.
United Utilities said that it needed to implement its enhanced sludge programme and had decided to use all the biogas for combined heat and power generation instead.
Thames Water’s project at its Didcot sewage treatment works which delivered the first-ever biogas pumped into the grid in October 2010 stalled just one month into production. The scheme, a joint venture between Thames Water, Centrica and Scotia Gas Networks, has not operated since – attributed to initial problems with new equipment and subsequent gas production problems at the site in the past six months.
Thames Water is hopeful that gas production will be fully operational by the end of 2011.