MWH, Stantec, Technical Director

Dr Stephen Palmer, Technical Director at MWH, now part of Stantec.

In the medium to long term, increasing energy costs mean the world’s economies have to transition from carbon based fuels to non-carbon substitutes to mitigate climate change. The world also needs to move towards a circular economy as human demand on global resources is in danger of outstripping supply and has reached super-exponential levels for some resources.

In the U.K. the national grid is under significant pressure particularly, under peak winter demand. The water industry consumes approximately 1% of UK electricity output but its impact is greater because household water and electricity demand coincide. The water industry is also under pressure to reduce operating costs and TOTEX. It’s a challenging time for the industry but there is one solution that helps partially mitigate all these challenges.

If energy recovery from sewage sludge is maximised, then wastewater treatment cost to serve and operational carbon footprint can be reduced simultaneously. This would also reduce dependence on grid power.  Using biogas as an energy storage resource could double up as a hedge on sludge transport fuel costs for a technology platform which could maximise resource recovery for the water company. The cost savings on demand response measures alone are worth more than £84million per annum on a conservative estimate and the technically recoverable renewable power potential is more than treble current water industry renewable power output, which all can be accomplished while recycling phosphorus to agriculture.

Read the full article published in Institute of Water Magazine, Autumn Edition 2017 – ‘Energy Recovery is the key to reducing WaSCs ‘cost to serve’ and carbon footprint’ here. 


Sludge production graph-01