Energy use in reticulated water supply

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As part of Beacon’s research into water demand management approaches, the water team also considered the relationship between treating and supplying reticulated water and the energy used in those processes.  They studied four councils: Nelson City Council, Waitakere City Council, Kapiti Coast District Council and Palmerston North City Council. These council-managed water supply and wastewater systems were analysed for their relative energy use and energy efficiency of the various water supply and wastewater situations.

The results showed some variations in energy efficiency between the systems and a consideration of relative energy use between sectors.  Despite the stringent requirements and public expectations placed on our water systems, there are still a number of approaches that could be made to reduce energy requirements and which could become a focus for infrastructure managers and designers to pursue.

From overseas experience and the observations from our data analysis, there was scope for further innovations or alternative solutions to be considered when designing systems or considering what sort of solutions to use.  These include:

  • Minimising energy use when designing new water/wastewater infrastructure.
  • Reviewing the maintenance features of existing plants to improve energy efficiency.
  • Making best use of natural local advantages that might allow gravity feeding or good quality water which requires less treatment.
  • Capturing co-generated energy sources such as methane from wastewater treatment to reduce cost and carbon emissions.
  • Providing on-site renewable energy to power the operations.
  • Considering the provision of services which are fit for purpose e.g., not treating all water sources to a potable standard.
  • Considering local small scale water systems for smaller communities which can be tailored to site specific conditions, rather than a scaled down model of major infrastructure.

The research highlighted  the operational energy component of urban water systems, recognising that this factor should be given more weight in the design of reticulated water systems as energy costs rise.  It also signalled that a water demand management approach has benefits in a reduction of both water and energy costs.

  • 30-Apr-2010 (Conference paper WA7090/9)

    Energy-Water Relationships in Reticulated Water Systems (PDF 348KB)

    Maggie Lawton, Ben Kneppers, Damon Birchfield

    SB10 New Zealand, SB11 Helsinki

  • 31-May-2009 (Report WA7090/2)

    Energy-Water Relationships in Reticulated Water Infrastructure Systems (PDF 342KB)

    Ben Kneppers, Damon Birchfield, Maggie Lawton

    The report provides an initial analysis of the relationship between energy use and reticulated water supply and wastewater treatment.  A literature study was supplemented by energy and water use data from four distinct reticulated water systems (Waitakere, Palmerston North, Kapiti and Nelson).  The data was considered for energy use and energy efficiency, and how improvements could be made.