19 May 2016 | Adam Leach
From scoping out potential improvements to tracking and measuring their impact once implemented, each step of the benchmarking process is dictated by the quality of data gathered.
First, the unit of measurement must be clearly defined. Initially, industrial benchmarks were measured in terms of kilowatt-hour (kWh) per unit of output, or Specific Energy Ratios. These days, Kwh per square metre, or Normalised Performance Indicator, is used. The benefits enable comparison between both buildings owned by a single organisation and also against data sets of external but comparable buildings.
Secondly, the scale of the data being collected must be methodically designed. A straightforward approach for an office block would be to monitor the energy usage of each floor for comparison, but in more intensive industries it is crucial to base the design around where energy use is greatest. Alongside the energy data itself, contributing factors such as time of year and employees present enable more comprehensive measurements.
Third, but no less important, is putting in place the periods at which data will be gathered. With smart sensors and sophisticated software in place, daily sets can easily be gathered, but where resources or technology are limited, weekly or even monthly recordings will still provide value.
If historical data from which to compare current use is not available, it may be possible to generate data from past invoices and sales records, otherwise the first year is just used to establish a baseline while comparing it against data sets of other, similar buildings.
For companies just starting out, or looking to alter the current benchmarking system, the Better Buildings Trust advocates a 'graduated approach' where the level of detail and sophistication is built up over time.
While the most effective and useful audits should always be carried out by an experienced external party, there should still be close collaboration with the company being audited. Before it is carried out, the auditor and the lead assessor internally should agree the full scope and purpose of the audit, outlining things such as specific areas with intensive energy usage such as server rooms.
Finally, it is all about ensuring goals are met. The overall objective could well be simply based on the overall cost saving delivered by an efficiency improvement; however, other factors such as any extra productivity or maintenance gains, and comparing alternative options on both a cost and energy usage basis, should be factored in.