Cost of electricity is continuing to increase as global energy prices continue to rise.
Wessex Water drives big savings with its Energy Hub
Wessex Water's Energy Hub is the focus of a drive to save operational energy. The hub collects usage data from 2,500 operational sites and models consumption to 99.9% accuracy. Andrew Pearson looks at the system that is saving the company hundreds of thousands of pounds.
The need to comply with increasingly onerous energy legislation including CRC and ESOS.
Need to instil energy efficiency message throughout Wessex Water to drive down energy costs.
Small savings – big wins
In April 2014 the Energy Hub highlighted abnormal pump activity at a remote Sewage Pumping Station, north-east of Malmesbury, Wiltshire. The run/stop data in the pump telemetry tool showed that rather than the more normal stop/start operation, the pump had been running continuously from 5th to 11th April. The problem was identified as a damaged float switch. Data from the Energy Hub showed that identifying the problem and ensuring it was fixed immediately saved £144 in energy costs on a site where the annual energy cost is approximately £1000 – a significant percentage, which highlights the importance of looking after smaller costs in addition to chasing big wins.
The billing, monitoring and targeting, and pump telemetry systems are all excellent information sources when viewed individually, however it is the integration of these individual systems into a single user interface – the dashboard – that will deliver industry-leading accuracy and usability that will increase the number of potential opportunities for energy saving.
“Considering the huge volume and variety of information available, the Energy Hub goes beyond current methods of energy reporting both within Wessex Water and elsewhere, particularly when combined with key metrics such as flow rates.”
Laura Mann, Team leader energy services, Energy accounting team
“Pulling all the energy information together gave us a huge amount of data but without the guys in the field having access to this data we were struggling to engage with them in the need to reduce energy consumption. The Energy Hub was borne out of a need to make energy information digestible to them.”
Catherine Pedder, Energy services manager
“Energy needs to be everyone’s business so we’re spreading the message at Wessex Water by getting the right information in front of the right people with the launch of the energy saving dashboards.”
John Leonard, Energy programme manager
On 20th January 2012, the operations team at Wessex Water began to receive automatically-generated notifications warning of problems with the pump performance at a remote, unmanned sewage pumping station. The alarm had been triggered by Wessex Water’s monitoring and targeting software because of an unusual increase in the amount of energy being used to pump each cubic metre of sewage.
The notification prompted an investigation. This showed the problem was due to a pipework leak in the station’s valve chamber, which would have remained undiscovered until the station’s next scheduled site visit, some three months hence. Wessex Water estimates the delay would have cost £1,000 in additional electricity charges.
What happened at this remote pumping station in 2012 shows the value of combining electricity consumption and pump flow data to help identify problems and energy-saving opportunities. Wessex Water has a vast amount of billing and monitoring data from its 2,500 operational sites. Until recently combining this data effectively to identify efficiency and operational savings had proved difficult. That has now changed with the launch of the company’s Energy Hub.
The Energy Hub is the focus of Wessex Water’s drive to save operational energy. The hub is home to the vast amount of data the company has on electricity consumption, assets, financial reports and site-specific flow rates. It is supported by computer-based interfaces – energy dashboards – which are currently being rolled-out to all of Wessex Water’s operations team.
Designed and programmed by Wessex Water’s Energy Team the interactive dashboards provide the operational business with a user-friendly means to integrate the huge amount of cost and operational data into a single system to help save energy and cut costs. “The energy team are experienced in interpreting and analysing complex sets of data; the idea of the dashboards is make it easy for the rest of the business to interpret and analyse that data,” says Wessex Water energy services manager Catherine Pedder.
The dashboards can be individually configured to show energy data and asset information pertinent to the user’s specific role; the chairman, for example, might chose just to have a view of headline data, while the operator responsible for an individual site is able to access information on the performance of the site throughout the day. By enabling access to good quality data the dashboards will enable the operations team to identify items of plant, systems and even entire sites where intervention could improve performance and reduce operational energy use and, hence, costs. What’s more, the quality of data on the system enables operators to demonstrate the level of savings achieved through their interventions.
The roll-out of the dashboards is the most recent element in the development of Wessex Water’s Energy Hub. “As the number of quick-win initiatives diminishes, maintaining asset efficiency and identifying when to take appropriate remedial action will be central to managing energy costs in future years,” explains energy programme manager John Leonard.
Energy costs derived from billing data are one of the main sources of data for the Energy Hub. However, to a major consumer such as Wessex Water, the cost of energy varies depending on the time of day and season in which it is consumed and is billed on more than 25 different tariffs.
To ensure energy costs are accurate, as part of the Energy Hub project Wessex Water’s Energy Team has developed their billing software in-house. This is capable of modelling the complex electricity industry billing rules in order to accurately estimate monthly electricity costs and to produce cost forecasts and energy budgets. In total the software processes more than 23 million rows of consumption data and 22,000 electricity bills a year. “As a result of this we are able to model the company’s multimillion pound energy bill to an accuracy of 99.9%.” says Laura Mann, energy services team leader in the energy accounting team.
Electricity tariffs have a huge impact on the cost of electricity; two of the most significant are Triad and Distribution Use of System (DUoS). Triad is a charge levied on industrial users by National Grid for the consumption of electricity at peak demand times. It can result in cost increases of up to 700% for using power during the three annual triad periods. In addition, DUoS has three main tariffs: red, amber and green. Industrial consumers can pay up to 21 pence more per kilowatt hour of electricity consumed during red tariff period (between 4pm to 7pm each day) than for the green in the Wessex region.
Avoiding peak tariff periods by pumping water into the distribution system outside peak electricity cost periods, for example, can deliver significant cost savings to the business. To help operators plan run times the dashboard includes a radial graph with the day divided into half-hourly segments coloured red, amber and green depending on the tariff. To date, DUoS avoidance has saved the company in excess of £300,000.
The accuracy of the billing software has also enabled the energy team to identify anomalies in suppliers’ bills. This included a failure to model the Triad charge accurately, the correction of which avoided £134,000 of charges over the course of a year. The team also identified that incorrect rates for low voltage power were being applied, which, if left unchanged, would have resulted in £7,500 in increased charges. The software also flagged a flaw in the electricity supplier’s software, which meant it was not immediately reflecting the one-hour time change at the switch between BST and GMT. “Due to the level of accuracy of the software and detail applied by the accounting team, Wessex Water is often the only customer able to bring these anomalies to the power supplier’s attention,” explains Mann.
The billing software has even had an impact on the cost of the Carbon Reduction Commitment (CRC) for Wessex Water, where the use of more accurate data has enabled £100,000 to be shaved from the CRC cost to the company. It will also be useful in dealing with the EU’s forthcoming Energy Saving Opportunities Scheme (ESOS), a directive which makes it mandatory for large organisations to carry out, and report on, energy audits.
In parallel with the work on billing, Wessex Water is able to monitor sites and individual assets using complex calculation engines. Information is collated from 1,700 sites and 5,000 individual drives allowing accurate benchmarking, forecasting and exception reporting. The pump telemetry tool alone saved more than £6,000 between November 2013 and March 2014 by identifying continuously running pumps.
At one sewage pumping station, for example, the system identified a problem when the specific energy of the site’s pumps exceeded a predetermined threshold. This was found to be the result of worn impellers on two of the site’s three pumps, which were subsequently refurbished. As a result, the intervention and improvement in pump efficiency on this site alone is estimated to have saved Wessex Water £3,000 a year. “Our increased use of monitoring and targeting is building up a system that identifies and maintains efficiencies,” explains Leonard.
Further savings are expected now that the interactive dashboards are being rolled-out across the operations team under a six-month programme. To ensure the team gets the most from the system, the roll-out is being accompanied by regular visits from the energy team to resolve any queries and to ensure the system is being used effectively to save energy.
- Interview: Duncan Atkins, MD, Imtech Water, Waste and Energy ''I'm looking to ensure construction excellence on all our projects, through drive, passion and energy. I want to... Read More >
- Technically Speaking: sludge dewatering at Bran Sands Real-time control processes are allowing the optimisation of the sludge dewatering process at Northumbrian's Bran Sands... Read More >
- Powering the pumps: electric or diesel? The question of which power source to use for portable pump sets can be a difficult one, with both electric and diesel... Read More >
- Comment: Optimising energy usage in the water industry Servelec Technologies' technical director, Marcus Fowler, discusses how the potential of demand-side response... Read More >
- Why do motors fail? Pump motors can run for half a century if they are properly maintained, writes Dave Hawley Read More >
- Bioresource data leads to focus on sludge quality The recent publication of data about the quantity and quality of sludge produced at water company wastewater treatment... Read More >
- Automation: the key to unlock energy efficiency Huge energy savings can be made by controlling pumps and other equipment using variable speed drives and automation, writes... Read More >
- Round Table: Water companies and demand-side response The attractiveness of demand-side response as an additional income stream for water companies is clear, but utilities need... Read More >