Integrated Environmental Biotechnology - Environmental Biotechnology: Theory and Application - page 265

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One significant advantage of this process is that the yield of methane-rich biogas
is high, which enables maximum recovery of the biomass energy to be achieved.
Feeding this into five state-of-the art combined heat and power cogeneration engines,
rated at 1.4MW apiece, will produce up to 5.5MW of electricity. The combined
heat and power produced will allow each site to be effectively energy self-sufficient,
have the additional capacity to be able to meet the needs of the adjoining wastewater
treatment and, in the case of the Afan site, also export up to 1MW of electricity to
the grid.
Aside of their role in energy production - tipped to cut D wr Cymru's overall
carbon footprint by around 15% - the plants will also provide a beneficial use for
the sewage sludge product. After dewatering, the pathogen-free sludge-cake will
be distributed across South Wales for use as an agricultural fertiliser/soil enhancer,
ensuring that this multifaceted project also dovetails into the ongoing regional
attempts at improving sustainability.
Between cutting energy usage, supplying more consumers and improving
water/wastewater treatment quality, the water industry as a whole has been asked
to perform an increasingly awkward balancing act. Accordingly, initiatives like this
one, in which biotechnologies for effluent improvement, beneficial waste recycling
and bio-energy generation combine to provide a single comprehensive solution,
may become increasingly common in future.