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Decarbonising the UK water industry - how low can it go?

Reducing carbon in the water industry may need more than a nudge from the regulator, says Alastair Chisholm, CIWEM policy manager

The UK is an international climate trailblazer. It is the only nation to set itself legally binding targets for carbon reduction and failure to achieve them could see the Government taken to Judicial Review. The Climate Change Act 2008 is a piece of legislation of which UK citizens should be justly proud. It shows that the UK will lead by example on the international stage to proactively mitigate and adapt to climate change.
The problem is, unless the Act is repealed, (a tantalising prospect no doubt for some in the Treasury but, on balance probably unlikely given the furore that would be unleashed from the green lobby) all sectors of the economy and wider society must now actually do something real and tangible. What is more, the numbers are big.
For those who’ve been living in a cave the past few years, we need an 80% reduction in CO2 equivalent, from a 1990 baseline, by 2050. The problem with 80% is that it’s such a significant proportion of the whole that not many sectors of the economy can wriggle out of doing their fair share. Sure, there’s a little room for manoeuvre, broadly though, most businesses and industry will need to think big.
So, water industry, make your bidding. Here is your profile:

  • Approximately 1% of the UK’s greenhouse gas emissions (roughly 5Mt per year, as of 2006/7)
  • The fourth most energy intensive industry in the UK
  • Capital expenditure of around £3bn per year
  • An economic regulator which has been rather cautious to date in encouraging environmental improvement of this kind, but which appears to be increasingly on-message

“Deep emissions reductions... will only be readily achieved by water and sewerage companies because the sewerage side of the industry offers significant potential for renewable energy generation”

So there is potential, but also one or two pretty big caveats and the biggest of these is that water will always be water and it is heavy, energy-intensive stuff to pump around. The industry is increasingly aware of the scale and nature of its emissions – both operational and embodied.
The cost of energy is a prime driver as the vast majority of operational emissions are associated with grid-generated electricity. There is an increasing body of work looking at the areas of potential energy efficiency gains and emissions reduction for the industry. CIWEM is undertaking its own analysis which draws on this and proposes key priority areas for action.
At this point, it is necessary to state a clear reality: deep emissions reductions in the water industry, of the order of those required by the Climate Change Act, will only be readily achieved by water and sewerage companies because the sewerage side of the industry offers significant potential for renewable energy generation through biogas production. Water-only companies simply do not have this opportunity at their disposal and may have to resort to the purchase of low or zero carbon grid electricity.
So what is the model for a big emissions reduction? There are some key areas for potentially large savings. These include putting less treated water into supply, resulting in less need for treatment and pumping.
Central to achieving this will be effective demand management and leakage reduction. The average domestic customer uses 150l of water per person per day. Government targets hope to reduce this average to 130l by 2020, and there is the potential to go far further than this with the right combination of awareness and use of efficient appliances.
If we also consider that up to a third of all leakage is from customer supply pipes, and much of this could be prevented with assistance from the improved leak detection afforded by widespread metering, there is the potential for significant gains. Pressure management to control leakage and burst frequency is widely practiced but could be further optimised with improved data and telemetry.
Network and process optimisation are two other areas where rigorous analysis of pump and process efficiency, allied to improvement programmes, can also achieve some big savings. Certain treatment processes are highly energy intensive, such as aeration, ozone treatment or activated sludge treatment. There is of course a strong drive for improvement of local water quality to meet standards under European directives and this has driven a significant increase in the energy consumption of water companies as they are required to treat to higher and higher levels.
From a sustainability point of view, some companies are beginning to look again at some of the less high-tech processes which may deliver similar performance, but with less energy use and carbon emissions, albeit often with significantly larger land-take, for example, trickle filters or optimising primary settlement.
Elsewhere, there is a need for smaller measures which combined will deliver collectively larger results. The use of micro-hydro power generation allied to pressure reducing and other control valves can power small amounts of local equipment.
Solar photovoltaic panels are becoming increasingly affordable and can again begin to make small inroads on the amount of electricity required to be purchased. There may be significant potential in direct heat recovery from wastewater, using heat exchangers and pumps, either allied to in-sewer systems or at treatment works. However the other big ticket item is biogas optimisation from anaerobic digestion of sewage sludge.
In any event, it will not be possible to achieve the savings required without a renewed research and development drive. The need for innovation in the water industry is clear and this aspect of activity is one that has suffered in the years since privatisation.
Annual spend on research and development is estimated to be in the region of £18M across the industry. In a sector with capex of £3bn a year, this is poor. Somehow the industry needs to share its experience and drive innovation faster to the commercial stage.
Finally, the economic regulator must grasp the decarbonisation nettle and actively encourage the water companies to reduce their emissions. The water industry is increasingly being labelled as an environmental management industry.
It will need to engage more actively with its customers to help them reduce their own water-associated emissions and with land managers, such as farmers, to help to reduce treatment requirements through improved catchment management measures – reducing pollution at source. It will also need to examine its own direct and indirect energy use and emissions and make reductions across the board.
The regulator could do worse than incentivise this in a similar way to which the Committee on Climate Change sets carbon budgets under the Climate Change Act. Progressive emissions reduction targets at each price review, with companies afforded the freedom to determine how to meet them?
Something for the regulator, Ofwat, to ponder before the next Price Review - PR19. nnn

Topic: Policy & Regulation
Tags: climate change , emissions , CIWEM , carbon reduction

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