Carbon Trust Advanced Metering Trial – United Kingdom
This is the 9th article in a series highlighting the case studies of DSM Task 15, Network Driven DSM. This Task demonstrated that DSM can be successfully used to support electricity networks in two main ways:
1) by relieving constraints on distribution and/ or transmission networks at lower costs than building ‘poles and wires’ solutions, and
2) by providing services for electricity network system operators, achieving peak load reductions with various response times for network operational support.
The Carbon Trust was set up by the United Kingdom Government in 2001 as an independent company and is funded by various government agencies. The Trust’s mission is to accelerate the move to a low carbon economy by working with organisations to reduce carbon emissions and develop commercial low carbon technologies.
From 2004 to 2006, the Carbon Trust carried out the first UK field trial of advanced metering for small and medium enterprise (SME) end-users. The trial aimed to demonstrate the potential benefits of the technology and understand the business case for encouraging widespread adoption of advanced metering by SMEs.
The trial was devised with the following high-level objectives:
- to understand the potential benefits of advanced metering for SMEs;
- to stimulate market demand by demonstrating that advanced metering can reduce energy consumption and costs;
- to help understand the barriers to broader uptake and how they might be overcome;
- to identify the nature of advanced metering services which yield the best savings;
- to develop case studies, highlighting the advantages of advanced metering;
- to quantify the potential UK-wide carbon savings attributable to advanced metering in the SME community; and
- to identify potential policy measures to stimulate uptake.
The Carbon Trust advanced metering trial was unusual in that it was implemented by a government-owned independent company rather than an energy business and it focussed on savings in total energy use rather than peak load reductions. The trial clearly demonstrated how advanced metering can enable businesses to identify energy, cost and carbon savings by providing detailed information about the ways in which they use electricity.
The Metering Trial
To deliver the field trial, the Carbon Trust contracted with seven consortia, all of which were already operating commercially in the metering market in the United Kingdom. The delivery consortia each recruited portfolios of SMEs or SME-like sites and installed advanced metering for electricity, gas and water at these sites as appropriate (not all utilities were metered at every site). A total of 582 sites across the United Kingdom were involved in the trial.
A total of 64 trial participants already had advanced electricity meters installed. For these sites no meter installation was necessary; all that was required was access to the existing half-hourly data. These sites were treated as a control group to investigate differences in use of advanced metering services between sites with and without existing interval metering. The findings from these sites were excluded from the bulk of the analysis in order to understand the potential for advanced metering in the SME sector where sites do not currently have interval metering in place.
Of the remaining sites, 73 made use of ‘pulsed-output’ meters with the capability to record half-hourly data through the use of clip-on readers. These readers enabled half-hourly data to be obtained without the need for upgrading the primary meter. At the remaining 455 sites, existing manually read meters were replaced with new advanced meters.
In addition to installing clip-on readers or new advanced meters at sites that did not already have interval metering in place, a variety of different types of energy saving advice were provided to sites during the trial. These services ranged from basic data provision to detailed advice on energy saving communicated through phone calls and site visits. Following are summaries of the types of energy saving advice provided.
Data Only (134 sites, including 39 sites with pre-existing interval meters). The most basic offering was the provision of metered data only, normally via a website. Simple online tools were provided to allow sites to conduct basic analysis of their energy use profiles.
Data and Advice (112 sites, including one site with a pre-existing interval meter). This intermediate level of service typically consisted of data provision together with a review of the site energy consumption and some basic energy saving recommendations relating to the site’s energy use profile. This information was normally communicated via email.
Personal Contact (336 sites, including four sites with pre-existing interval meters). This level of service involved two-way communications with the site including detailed discussion of the energy use profiles, either via telephone or site visits. The delivery consortia provided site-specific recommendations and advice.
Figure 1 shows how detailed half-hourly load profile data from advanced metering was used to identify opportunities for energy savings. Three key types of potential energy saving measures (corresponding to the numbers in Figure 1) could be derived from advanced meter data:
Figure 1. Using Load Profile Data from Advanced Metering to
Identify Opportunities for Energy Savings
- Base load reductions – the overall base load of the site could be studied and reduced, for example, by identifying unnecessary constant energy use.
- Process optimisation – the load profile could be used to identify what equipment is running and when. Altering the start-up and shutdown times of key processes and equipment could reduce consumption by limiting the duration of high energy usage at the start and end of working schedules.
- Peak usage reduction – the load profile could be used to analyze timings and frequencies to identify the causes of peaks in energy usage, such as particular activities or equipment.
The consortia completed log books for each site, tracking the estimated energy savings for each recommendation and the extent to which each recommendation was successfully implemented.
A case study was also produced for each site to describe the overall actions taken and associated savings made. These case studies recorded the situation at the site prior to installation of advanced metering, including details about the organisation and annual energy consumption levels. Case studies included graphical data showing energy consumption and areas where potential savings had been identified. They also included the financial case for implementing energy saving actions and the levels of potential savings in terms of energy consumption, carbon emissions and costs.
As part of this process, the consortia reviewed the half-hourly meter data to identify and validate actual energy savings achieved. Where it was not possible to implement energy saving recommendations, the reasons for this were discussed with the site personnel and recorded for reference.
Detailed results of the energy savings identified and successfully implemented by the SMEs involved in the trial are shown in Figures 2 and 3.
Figure 2. Average Annual Energy Savings per Site
in the Carbon Trust Advanced Metering Trial
Figure 2 shows that, on average, sites in the trial saved around 13,500 kilowatt-hours of electricity and 30,000 kilowatt-hours of gas per year by using the information gained from advanced metering. This equates to annual total savings across all sites in the trial of about 7,860 megawatt-hours of electricity and 17,460 megawatt-hours of gas.
Figure 3. Average Annual Cost Savings per Site
in the Carbon Trust Advanced Metering Trial
Figure 3 shows the average cost savings identified and implemented per year. On average, sites in the trial saved around GBP870 on their electricity bills and GBP405 on their gas bills per year.
Figure 4. Carbon Savings by Type of Energy Saving Advice Provided
in the Carbon Trust Advanced Metering Trial
Figure 4 shows the percentage carbon savings achieved by the type of energy saving advice provided. The way in which energy saving advice was delivered to SMEs resulted in marked differences in the savings achieved.
The Data Only service, where customers were simply provided with remote online access to their energy usage data, led to the lowest levels of savings. However, even here 10% energy savings were identified and 3% implemented on average. These were significant savings, especially as this service was considerably less resource-intensive for the service provider to deliver.
Most notably, the Data and Advice service, where energy saving advice was provided remotely via email, led to the highest levels of energy savings, with an average of 15% savings identified and 7.5% successfully implemented. These savings are higher than those achieved for the Personal Contact service, in which advice was provided directly via site visits and telephone calls, where an average of 12.5% savings were identified and 5% implemented successfully. This is a significant finding and there appears to be two key potential reasons for this result.
Firstly, when service companies provide advice via site visits and telephone calls, the advice is generally highly customised and there is a tendency to focus on high value-added recommendations. These are likely to lead to more complex process-based changes or more expensive investment-based actions. There is also less focus on providing generic energy saving recommendations, such as simple information-based or process-based changes.
However, it seems that many SMEs, and especially those with limited prior experience of energy saving, can benefit from these “quick win” generic actions.
Secondly, energy saving advice which arrives via email is readily available and more likely to be looked at and acted upon directly than more conventional energy audit reports. This is especially true when the email contains simple, intuitive graphical information, such as daily energy consumption profiles. Also, the email format allows the information to be easily forwarded on to staff within the organisation to take the relevant actions, for example operations or facilities management personnel.
A key implication of this finding is the possibility of providing advanced metering services at significantly lower costs in the future. The email service model is highly scalable and it would appear feasible that automated systems could be used to analyse SME energy usage profiles, identify appropriate recommendations and automatically email these to the customer, with supporting graphical evidence. Such an automated service, backed up with call centre support, would allow for a significantly lower-cost service model than one involving on-site or telephone-based analysis and discussion.
This model for delivering energy saving advice could be easily adapted to deliver advice on reducing peak loads rather than reducing overall energy consumption.
The Carbon Trust trial is a good example of what can be achieved if advanced meters are actively used for data monitoring, collection and analysis as part of a comprehensive program focussed on realising energy savings. The systems developed for the trial could be easily adapted to deliver advice on reducing peak loads rather than reducing overall energy consumption.
Download case study here
This article was contributed by David Crossley, Managing Director of Energy Futures Australia Pty. Ltd and Senior Advisor at The Regulatory Assistance Project. For more information on this case study and others, visit Task 15, Network Driven DSM at: