Open menu

Industry Insights

Using data to optimise energy consumption across building estates and fleets

We spoke to Ian Lillie, Strategic Facilities Manager at North Tyneside Council, about the importance of using data to make informed decisions when introducing energy efficiency measures.


Data is an energy manager’s best friend. It can play a key role in making informed decisions on ways to optimise energy consumption and identify trends across building estates and fleets.

Ian Lillie knows this only too well having spent the last few years fully revitalising a Grade 2* listed building, the Killingworth Site. The site is home to around 1,000 council staff and is the council’s main fleet and operations depot.

A core aim of the initiative was to futureproof the site in line with the council’s net zero aspirations. Thanks to a range of measures, the site has already reduced its energy consumption from 3.5 million kWh/annum to around 1 million KWh/annum taking it from the highest energy user in the council estate to one of the lowest.

He talks us through some of the steps he took and the data he used to ensure his improvements had a quantifiable benefit…

Review existing energy data

“One of the first things I did when I was given the project to refurbish the site, was to take a detailed look at the data on the current consumption. The Killingworth site was the biggest energy user across our estate. It also had the biggest carbon footprint. So, we needed to get into the details of what was happening across all elements of the site and assess what changes and improvements we could make. To set a baseline for carbon reductions, we used DEFRA’s carbon calculator to model against our energy consumption.

“Being able to quantify carbon savings is key – the traditional ROI of cost savings are difficult to justify in the context of net zero as the driver. Data is key in demonstrating these outputs.”

Smart metering and heating zones

“The next step was to introduce a smart metering system to parts of the site which allowed us to measure our power, lighting and heating circuits in granular detail. This helped us to assess where the power spikes and anomalies were happening.

“From there, we introduced heating zones.  Our main building now has 46 separate heating zones which means that we can target the heating to come on and off according to when the rooms are being used.”

Solar PV

“Solar PV is an instant win for a site of this size but it’s important to size correctly. As we were driven by decarbonisation, I started by looking at the carbon savings of the range of measures we had implemented – including our air source heat recovery system. Collectively these reduced our energy consumption by 2.5 million kWh per annum – and of that remaining figure, 700,000kWh was electricity.

“My target was to reduce this amount to 200,000kWh through the introduction of solar. Once installed, we then measured how much solar we were exporting – which was 15% of our green energy going back to the grid. This is where the addition of battery energy storage comes in.”

Electrification of fleet vehicles

“Another key net zero measure that the council is taking is for our smaller vehicles to go electric by 2025/26. This means that there’ll be an additional 100 vehicles on site which all need charging.

“This will inevitably have an impact on our energy consumption so we’re using data to model this. Because of the size of the borough, most of these vehicles will travel about 200 miles a week. I’m already working closely with our fleet manager to assign charging schedules to vehicles to make sure that they can be charged from stored energy as much as possible.”

Battery energy storage

Battery energy storage was an important final piece in the jigsaw for the site.

“By using Connected Energy’s system, we can capture our excess solar energy and then programme the system to charge our electric vehicles and buildings overnight.

“This helps us to maximise the use of our green energy further.”

Note: This is an excerpt from an interview featured in our new whitepaper for energy managers

Download now

Our whitepaper outlines how battery energy storage (BESS) is a versatile tool for building decarbonisation. 

Get the latest insights, strategies and case studies to showcase the role that BESS can play in the journey a greener, more sustainable future.