How a strategic energy partnership delivered a 53% gas bill reduction

St Katherine’s School, a secondary school serving around 1,000 pupils, is one of 22 primary and secondary schools within the newly formed Amplify Education Trust across North Somerset and the wider Bristol area. Originally built in the mid-1970s, the campus has been extended several times, with the latest addition completed approximately 15 years ago.

This has presented a significant challenge for energy management, with each building having its own “energy quirks” as Alex Poulton, facilities manager at St Katherine’s, describes it.

The school also had an ageing building management system and desired to upgrade it as cost-effectively as possible to become more energy-efficient.

Rob Silvester, Head of Energy Flexibility at SSE Energy Solutions, says the introduction to St Katherine’s was from the energy consultancy Utility Aid, the energy procurer for the Trust’s schools.

An existing partnership with Utility Aid, which specialises in assisting charities and not-for-profits, includes a 100% renewable procurement from SSE’s wind farms.

Silvester explains that while St Katherine’s was initially highlighted for its forward-looking approaches, the project started with the creation of an energy performance baseline across all the 21 buildings of the Trust’s schools – a process that took about a month and the first step in a four-step strategy for decarbonising buildings that SSE has developed and is advancing countrywide.

“We took a year of energy data and used the ISO 52120 standard [for creating an energy efficiency rating] to produce a league table of the energy performance of the buildings, and from that we could identify those worst performing and those presenting the greatest immediate opportunity.”

Inputs included data such as energy consumption, costs, hours of occupancy and building size, among others, with most buildings in the UK having a D rating and the aim to move them progressively up towards an A.

Smart Connect

St Katherine’s was selected for the development of a proof-of-concept that could also be implemented in other schools and small commercial buildings.

“We opted to deploy our LoRaWAN-based Smart Connect solution, including a controller, occupancy sensors and thermostatic radiator valves,” says Silvester.

“With the single heat boiler, there is only limited manual control, but this solution gives connectivity across the entirety of the school and enables zoning and controlling the temperatures of individual rooms remotely via the cloud to meet the varying needs according to their occupancy, use or individual request.”

In total, 94 thermostatic radiator valves were installed covering almost two-thirds of the school, including several classrooms and staff rooms as well as communal areas such as the library and other common spaces – including many of the radiators.

“This has given a good spread across the school,” Poulton says, noting that some other areas have fan heaters or underfloor heating.

“The key point is it’s a scalable solution demonstrating that the assets can be quickly deployed, connected and controlled and can deliver savings,” adds Silvester.

Solution benefits

What are these savings? Apart from the obvious benefits of rooms being heated to a comfortable temperature without being under- or over-heated and the convenience of being able to reduce the temperatures remotely in unused rooms, there are significant benefits for the school.

Initial estimates put the expected savings at over 41,000kWh annually, corresponding to a cost saving of around £3,000 (€3,400). However, this has already been exceeded, even considering a change of provider, increased energy prices and a particularly cold winter.

“Comparing the winter months so far with 2024, the gas consumption is down in some by as much as almost 50%,” says Poulton.

With savings so far approaching the £3,000 (€3,400) level, that is significant against the estimated gas bill for the year of £32,500 (€37,400). These savings can then be fed back into other school projects.

“And it's literally come down from being able to individually control radiators and to keep the water temperature through the system closer to the set point,” Poulton adds, highlighting a challenge and additional spin-offs that have emerged.

One of these is open conversations with staff on energy efficiency. In the past, it would have been common for a staff member to turn up the heating first thing in the morning and then, when it became too hot, to open the windows.

“I’ve had to get them round to my way of thinking that the thermostatic valves are not the enemy but the friend, as the environment is going to be suitable and more comfortable for learning.”

Another significant spin-off Poulton mentions is the introduction by one of the teachers of a ‘green team’ in the school’s bi-weekly enrichment programme.

“They had me in to talk about our energy programme and they have access to the energy data and analyse it,” he says. “It’s cascading and spreading that sustainability is a good thing and not just about cutting back. You’re not one student in a school but you are part of a community and all have the chance to benefit that community.”

Next steps

One option for St Katherine’s is to complete the deployment of the thermostatic valves to the remaining radiators without them.

A second option, which is the third step after benchmarking and eliminating energy waste in SSE’s building decarbonisation strategy, is to better manage demand through the introduction of technologies such as solar, storage and demand-side flexibility.

“With this project, we have created a meaningful relationship with St Katherine’s, and we are now looking at how we can support the school with further decarbonisation,” says Silvester.

He adds that the proposal includes an innovative funding option that will deliver cost savings from year one and ownership of the assets to St Katherine's as well as their servicing and maintenance.  

“Financing is always a challenge for small businesses of this type for such projects and for whom the building decarbonisation strategy has been developed, and we have a range of financial instruments to meet different needs, for example, to encompass ownership or only management of the assets and PPAs.”

The full strategy also includes a fourth step of further decarbonisation, with, for example, the installation of heat pumps or local EV charging facilities and supply of 100% renewable energy.

Commenting on the good relationship that has developed during the project between St Katherine’s and SSE, Poulton adds that the school has been exploring the potential of installing solar PV for some time, but without any progress so far. With the approach proposed by SSE, they are keen to push for its go-ahead.

“It just makes so much sense and will be another feather in the cap of our partnership with SSE in sustainability," concludes Silvester.