As the adage goes, “You can’t manage what you can’t measure”. When it comes to measuring energy / carbon, it’s important to do this in a way that is helpful to being able to manage it.
Energy bills and associated meter readings are the starting point for this measurement however, whilst this information is important, it will usually only clarify total consumption by building or possibly area of a building/process. Additional granularity is needed regarding the operation and processes in order to start to quantify a useful operational baseline.
There are two ways of gaining this additional granularity. The first is to monitor the operation via sub metering based on a metering strategy, the second it to conduct energy surveys to identify and quantify consumption proportions and profiles.
Metering Strategy
Commissioning a metering strategy and the associated installation of meters/loggers is a great way of tracking consumption. Done properly, it will give an organisation everything it needs to monitor consumption, even producing alerts when consumption within predefined limits exceeds expected levels. The downside of this approach is the cost of the strategy, hardware, installation and ongoing monitoring. When considering a metering strategy, the Chartered Institute for Building Services Engineers (CIBSE) standard for what should be included (TM39) is a good place to start.
Energy Surveys
Energy Surveys are a relatively quick and inexpensive way to quantify the energy consumption of a building, process, operation or estate and will estimate what the reduction in energy could be, if operations were modified. In the UK, large companies are legally obliged to survey their operations as part of Energy Savings Opportunity Scheme (ESOS) regulations. In addition, business wishing to provide services to the public sector or other large businesses may have to demonstrate their plans to decarbonise operations as a requirement of the tendering process, for example Procurement Policy Note (PPN 06/21).
Commissioning a series of energy surveys, would also be the common starting point to generate a Net Zero Plan/Pathway/Journey, which is essentially a programme that shows how the businesses will reduce its carbon emissions to zero over a period of time. One of the standards that businesses currently favour is the Science Based Targets Initiative (SBTi) approach, to ensure their plans are quantified in-line with best practicse and able to be externally validated. As an example, below is the Net Zero Plan of NatureScot Net Zero, showing Scotland’s Nature Agency’s carbon trajectory including purchasing Carbon offsets to mitigate remaining hard to remove emissions in 2040.
When reviewing the options to reduce or generate energy, it is important to consider how options would work together, particularly if there are measures that have savings that overlap, for example Fluorescent lighting upgrades to LEDs and Voltage Optimisation. In the same vein, is also important to consider reducing the need for energy prior to installing more efficient equipment, for example installing insulation insulating prior to sizing a new boiler.
Survey Process
- An energy survey would normally start with a data gathering exercise and desktop assessment of consumption patterns and areas/times of high usage. Additional information is normally requested regarding the equipment on site including its age and condition which then lead into conversations with site staff explaining the operation of the site and ideas that have been thought of to reduce consumption.
- Following the initial data gathering exercise, a site visit would then be conducted to capture information including the electrical distribution, the heating and ventilation systems in use, the lighting and other energy consuming equipment, fabric (windows, walls, floor and roof) and occupancy/process timings. Any energy generating plant would also be documented (e.g. Solar).
- The information gathered is then compiled and presented, showing the opportunities to reduce consumption and generate power/heat and framed to suit the purpose of the investigation, be that for energy or decarbonisation. Whilst these purposes sound similar, taking a Carbon focused approach will negate consumption reduction opportunities that use fossil fuels, for example gas fired Combined Heat and Power (CHP) engines.
Typically, information is presented as a report and will show estimations of project paybacks, which if aligned with the companies operational plan, can then be used to generate an Investment Grade Proposal of programme(s) of work.