Electricity Monitoring System at St. Patricks Cathedral Grammar School

Electricity Monitoring System at St. Patricks Cathedral Grammar School

On February 20th, I visited St Patrick’s Cathedral Grammar School in Dublin to investigate installing an electricity monitoring system.

What we needed to do

Monitoring energy consumption is actually quite straight-forward: two clips need to be installed around the main electricity cables which are supplying electricity. This measures the flow of electricity through these cables – and since electricity only flows when it’s being used, this is exactly what we need to measure! By measuring at the source i.e. where the energy enters the building – we can measure the total electricity being used in a building from just one measuring point.

Example energy monitoring clips

Example energy monitoring clips to be attached to the main power cables

How we did it

First, we needed to understand where to measure the electricity. Staff members knew that there were two sources of electricity entering the school grounds: 1) the main school building and 2) the art room area (a smaller area). To get a complete reading of electricity consumption, both sources would need to be measured, but to get started we decided to just measure one source – the larger of the two – the main school building.

The measuring clips need to be installed around the incoming cables to the school. This is mains electricity so we have to be extremely careful – we can must turn off the power to the whole building in order to attach these clips. We agreed to turn off the power to building outside school hours and attach the clips – I will return to do this on my next visit and post a new update.

The data from these clips will be collected and sent using an internet connection to a remote server. This means that the meter readings will be available online (privately) for the staff and students to log-in and view. We found a network connection near the reception office which we can use to connect the energy monitoring system to the internet.

Example energy monitoring graph

Example meter readings from an energy monitoring system

Next steps

With the investigation complete, we are now ready to set up the system. On my next visit, we will turn the power off to the building, install the clips, and connect the system to the internet. From there, the school should be ready to start viewing their electricity consumption!


- Colm Byrne
Susliving Tech Mentor: Energy
You can email me with questions or advice at info@susliving.org