End Users Approach to Pumping System Optimisation
Simon Whatley Asset Design and Performance Consultant
Thames Water Asset Management
© ESR Technology Ltd.
Agenda Drivers – Green House Gas Emissions Drivers – Electricity Consumption Drivers - Maintenance Strategy – Pumping System Optimisation Framework Strategy – Asset Standards Strategy - SCADA
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Introduction Thames Water uses a 1,250,000,000 kWh year Thames Water spends over £80 Million on energy each year Thames Water generate 200,000,000 kWh a year 65% of our Green House Gasses emissions result from our energy consumption We have a target to reduce our GHG emissions by 20% by the end of AMP5 compared to 1990. Every investment decision has an energy implication
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Green House Gas (Carbon) Emissions Water Electricity Wastewater Electricity Sludge Electricity Aeration Electricity Biogas Generation Other Energy Wastewater Process Emissions 28/05/2010
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AMP5 electricity consumption increase Electricity Consumption 1400.0
1300.0
GWh
1200.0 PR09 submission desal Total generation Net electricity consumption
1100.0
1000.0
900.0
800.0 1
2
3
4
5
Years 28/05/2010
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Energy as a Proportion of Whole Life Cost?
Purchase Energy Maintenance Carbon
Whole Life cost of a pump for Kew TWRM Shaft measured over 20 years
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Maintenance Reduction Any small percentage gain in efficiency will be wiped out by extra maintenance visits Extra maintenance visits caused by: – Soft blocking as pump running too far away from best efficiency point – Nuisance trips from pump protection – Changes to operating points of wetwells – Raft formation – Poor screening – Wear 28/05/2010
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FA934 Pumping Station Optimisation Framework Four Lots – Water, Wastewater, Sludge, Aeration Optimisation survey of key sites Need to understand Specific Energy Consumption of each – kWh/litre/m head for pumping assets, kWh/Normal m3/m head for blowers, or kWh/kg of Oxygen for Aeration system efficiency Purpose to demonstrate degree of optimisation of assets, and scope required to optimise Ofwat are expecting to see savings of £3.5million – this is a reportable output
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Contract Strategy for FA934 – Pumping System Optimisation The official OJEU notice for FA934 was published on 15th July 2009 22 suppliers responded and were evaluated; Recommendation Report currently being signed off The new agreements will start soon Project Team to prioritise initial lists of sites for the suppliers to investigate from May 2010 Communication of the Pump Efficiency projects - via Power Optimisation Steering Group to ensure maximum visibility and buy-in from the operational sites involved
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Contract Strategy for FA934 – Pumping System Optimisation Contractor KPIs used to calculate how much will be paid to the supplier include: – Accuracy of forecasted savings against savings achieved – Achievement of project timescales – Invoicing accuracy – Customer feedback from site operatives – Effective management of third parties TW have the option at the end of each stage to end the process
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Project Success – Risks & Issues Operations need to have confidence in savings and agree that they are achievable Recommendations will be facilitated by Training. Pump testing must not disrupt site operations during a drought, if there is a compliance challenge and any other operational issues . Pumping strategy must comply with Ofwat pressure requirements. Ability of Operations to implement any recommendations at all stages of the testing / analysis will eliminate any proposals which will not ultimately be viable. Project governance will be critical
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FA934 Execution Stages Three stages. Stage 1 is a data gathering exercise looking at what pumps are fitted and what the station is supposed to pump, where it is pumped from and to, and when it is to be pumped. Existing Automatic Meter Reading and Sub metering data to be used in decision tool As part of stage 1, the existing maintenance is reviewed along with the operational performance to make an assessment of whether the level of maintenance has affected the station’s reliability
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Automatic Meter Reading
AMR programmed for all non – half hourly sites (small pumping stations & all treatment sites) 2850 sites now have real time half hour data on electricity consumption available – as above showing kWh against time Program to be completed by Dec 2010 (all TW sites) Data can be used to compare relative performance of similar sites
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Energy use on pumps and blowers represent a large proportion of total site energy usage
The charts below show the general split between the main energy users on operational sites
Energy Usage on Wastewater Sites
Energy Usage on Cleanwater Sites
5%
5%
15% Blow ers
25% Pumps
Pumps 20%
60%
Processes
Processes
Overheads
Overheads 70%
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FA934 Execution Stages Stage 2 is the analytical stage. The contractor is expected to test the station and determine whether it is doing what it is supposed to do as efficiently as possible and to determine its specific energy consumption (kWh/litre/metre head). This will give us a future benchmark to compare the station in the future. The contractor will then review the stage 1 data along with the test data to make recommendations as to how the efficiency and reliability of the station can be improved, an estimate of how much that will cost and what the return on investment will be. Develop a Whole Life Cost model of the station.
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FA934 Execution Stages Stage 3 execution path will be determined by Thames Water. There are three options: 1.
Get the efficiency contractor to project manage the upgrade and be responsible for delivering the forecast results
2.
Incorporate the work as part of a capital scheme to be undertaken by a Tier 1 contractor
3.
Review the results and add it to the PR14 review to be included in AMP6 or subsequent upgrades
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Energy and Carbon Asset Standard Provides guidance on how energy and carbon management requirements are to be incorporated into design, construction and commissioning phase of capital projects. Includes mandatory requirements for metering, measurement and reporting of energy management information and data Seeks Whole Life Cost solution for all capital projects – mandatory Energy Efficiency best practice technologies acceptable for all assets – energy avoidance & energy saving; fossil fuel replacement Renewable Energy Generation guidelines
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Whole Life Cost – part of new standard Developed alongside WIMES LCC model – Water Industry standard WLC calculated for any assets that use electrical load Widened to encompass pumping systems not just pumps £ Components – Purchase, Energy, planned and unplanned Maintenance & Carbon footprint Commissioning – validate the commissioned article against base data the contractor has used to justify design Benchmarking – data can be used throughout asset life Inputs to model can be easily accessed – supplier & in-house
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Asset Standards Upgraded Pumping Station Asset Standards to govern behaviours Pumping Station Design Standard– requires contractor to calculate Specific Energy Consumption (kWh/Megalitre/metre head or similar) and demonstrate least whole life cost in solution. Preference stated for dry-well conventional design (easy access to mechanical seals). Generally better overall efficiencies and lower maintenance costs. Whole life cost of whole solution to be used to determine design Further work is to be done to improve existing standards as we progress and our understanding of issues improves – this is a continuous process
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SCADA Site SCADA systems to more explicitly show energy consumption Pilots planned – Cockpits at Reading STW, Lane End WTW – Aeration control at Oxford STW – Filter backwash control at Fobney WTW – Sewage pumping station control
Develop pilots into standard specs Templates for data collection & information display Change from historic to real time control of energy use 28/05/2010
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Energy Process Sub - Metering 20 sites to be completed in 2010/11 Trials at Swindon, Hampton & Kempton Used to pinpoint which process uses more energy on-site inc efficiency performance Site SCADA systems to show real time energy consumption at process level Process energy performance available at corporate & management level Comparison against similar processes on other sites – kWh/MLD, kWh/kgO2 28/05/2010
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Summary The new framework will allow us to continue to review pumping station performance, assist in building up our asset database Understanding the Whole Life Cost of the asset is critical to reducing Energy consumption and Carbon emissions. The changes to Thames Water’s standards will start to generate savings and by using specific energy consumption, make it easier for us to assess when a pumping station needs intervention. The new framework will turn the focus on to whole life cost during operation
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