Energy monitor equipment was installed in over 100 properties in Orkney as part of the ReFLEX project. The goal with each installation is to achieve the highest granularity of data as possible. However, the installation team encountered huge variations in distribution board connections across the properties taking part in the trial, and were often met with physical barriers to connecting energy monitoring equipment for optimal load measuring.
Challenges encountered in energy monitor installation
Installing energy monitors is subject to how distribution boards have been wired by the electrician to best suit the property and the loads. The Efergy metering equipment used operates by placing CT-clamps around power cables to infer power, rather than in-line metering, and therefore there were physical limitations to installation.
The energy monitors can be used to monitor and isolate specific sections of household energy usage like the heating system, heat pump, solar panels, electric vehicle and any other energy loads, when the distribution board and meter cupboard set up allows. This would mean capturing the power consumption for the whole property as well as individual loads, and if present, micro generation. However most were only able to monitor whole house energy usage due to the following issues in installation.
Meter cupboard set up, accessibility of wires and the requirement to isolate loads
The installation team encountered many restrictions within distribution board and meter cupboard set ups. It wasn't always possible to record all energy loads to gain a well-rounded overview of the householder’s energy usage due to inaccessible wires.
For example:
- There were often issues with the wiring of the meter cupboard with some cables inaccessible, and/or cable ties used to keep cables neat and tidy preventing monitoring equipment being installed to access certain energy usages.
- Certain scenarios meant that monitoring equipment could not be installed due to restrictions within metering cupboard. Potential wiring was inaccessible due to cable ties or confined spacing between meters and other equipment (consumer units, junction boxes).
- In some homes the wiring was covered by plastic casing which meant assumptions had to be made of where wires were feeding into and did not allow for energy usage to be recorded.
Whilst efforts were made when analysing the available data to produce valuable assessments, when only the whole house’s power consumption could be monitored multiple assumptions had to be used to reach conclusions. This highlights the value of isolating loads within the property to get more detailed data sets.
Power cable challenges
The metering equipment relies on the electromagnetic field produced by current in power cables. If the power cables have more than a single core (i.e. live and neutral) then the fields cancel each other and no readings are available.
Cost considerations
There are metering options which would have navigated the issues highlighted above, but they come with significantly higher costs. However, Efergy equipment is great value for money when CT-clamps can be used. Therefore, it is recommended that when properties are being built or amended, distribution boards are configured in a way that CT-clamp based energy monitoring can be installed simply and easily by the owners. For example, easily accessible single-core cabling that is clearly labelled. This should especially be the case for new or existing electrical heating; which would typically be the highest loads in the property, and focus for energy efficiency monitoring.
Learnings for future projects
- For policy makers: meter cupboard and distribution board set up and accessibility of wires needs to be re-considered to aid the installation of CT-clamp based energy monitoring equipment.
- For homeowners: to make requests, in their own interest, to have access points within their own distribution boards for CT-clamp based energy monitoring.
