ESOS progress update deadline looms: Verco’s key insights from Phase 3 data.

The deadline to submit the first ESOS progress update (PU1) is December 5^th 2025. The Government recently released data from ESOS Phase 3 submissions which gives us insight into the measures that businesses planned to adopt and the energy savings they anticipated making.

This article explores the answers to the big questions all businesses should be asking about the recently released data: Did we deliver on the expected energy savings? and what can we learn, based on the types of measures businesses planned to deliver between 2024 and 2027?

If you are reflecting on the energy saving progress your business has made this year and the savings you anticipate making in 2026, this article will give you an insight into three areas:

1. What savings did businesses expect to make by now?
2. What range of measures did businesses plan to deliver?
3. How can businesses accelerate progress in 2026 and beyond?

1. What savings did businesses expect to make by now?

In an ever-changing geo-political landscape, decarbonisation might seem hard to prioritise or deliver. Alongside global uncertainty, businesses know they’ll be affected by the impact of climate change – for example, the financial risk their assets are exposed to from physical and transition risks – but they don’t know exactly to what extent, or where or when.

It is why a strong regulatory environment and schemes like ESOS are important. They continue to drive greater transparency and disclosure, present opportunities for businesses to learn from their in- and out-of-sector peers, and drive further energy savings.

We know that the ESOS data release doesn’t account for every energy saving measure businesses complying with ESOS will implement because businesses weren’t required to commit everything they intended to do. However, the data offers an insight into those measures businesses arguably felt most confident about delivering and/or already had in motion.

Despite that caveat, a considerable 4,032 GWh was expected to be saved across 2024 and 2025, which accounts for 62% of the total expected energy savings across 2024 – 2027.

Although we don’t know how much of the planned energy savings have been achieved, it’s never been more important that businesses remain committed to energy and carbon reductions. Based on the ESOS data, there’s a strong indication that businesses weren’t going to delay the implementation of energy saving measures.

2. What range of measures did businesses plan to deliver?

By organising the energy saving measures using common key words, we had a closer look at the types of measures businesses were committing to.

Lighting leads the way: it’s neither surprising nor perhaps that exciting to learn that ‘lighting’ was the fourth most common word in the list of energy saving measures. With ‘LED’ and ‘upgrade’ also in the top 10 most used words, it strongly suggests energy efficient lighting remains a business staple for energy management.

Deliver first, optimise later: ‘solar’, ‘heating’, and ‘pv’ also feature heavily in the list of measures detailed in ESOS submissions. Much like with ‘LEDs’, those measures have a heavy bias towards delivering savings in 2024, suggesting there was plenty of low-hanging fruit still available to businesses when they made their ESOS submission. Notably, estimated savings from ‘optimisation’ are set to more than double in 2025, with a sharp rise also seen in ‘monitoring and controls’.

Heat decarbonisation might be under utilised: for many businesses, especially industrial organisations, implementing heat decarbonisation technology can be the largest step to net zero. For industrial operations, it typically accounts for 50-70% of site emissions reduction. However, only a tiny fraction of ESOS energy measures feature heat decarbonisation such as ‘CHP’ and ‘thermal’. The overwhelming number of solutions, possibilities and combinations available might explain why heat decarbonisation is potentially being under utilised. We help our clients cut through the confusion with our freely available technology mini guides and a fast and low-cost low carbon heat blueprint service. Read our recent article on the topic here

3. How can business accelerate progress in 2026 and beyond?

Of all the measures captured through ESOS, we have focused in more detail on two types of energy reduction measures that are readily available to businesses looking to drive energy and cost savings.

Drawing on the ESOS data and Verco’s experience of delivering projects for clients across a range of industries, both building optimisation and heat decarbonisation offer promising energy savings and should absolutely be a part of your energy reduction plan for 2026.

Alongside a brief overview of the respective opportunities you’ll find links to free resources developed by Verco’s team of experts, including mini guides, webinars and articles to help you unlock energy reduction savings.

1. Building optimisation

Energy measures relating to optimisation accounted for the highest expected energy savings in buildings in 2025, with 134 GWh expected to be saved, and the same was also true in industrial as well (106 GWh savings expected in 2025).

If we couple measures referencing ‘optimisation’ with those mentioning ‘monitoring’ and ‘controls’, in buildings alone, over 257 GWh was expected to be saved in 2025. We’ll have to wait for the PU1 update later in 2026 to know how effective those measures were, but it’s clear that businesses had huge expectations for what could be achieved through better optimisation.

Many of the optimisation measures are relatively low-cost and easy to implement, with potential energy savings of up to 30%. To help you make the most of the optimisation opportunities, Verco have developed a range of resources which are free to access:

The value of building optimisation on-demand webinar

Building optimisation expert interview in Property Week

2. Heat decarbonisation

Less than 1% of energy savings in buildings and industrial processes made reference to the heat decarbonisation levers we reviewed for either 2024 and 2025. Whilst heat pumps are expected to contribute a little more in later years (5% in buildings in 2027 and 3% in industrial in 2026), it’s clear that many businesses didn’t expect immediate opportunities from them.

That isn’t necessarily surprising. Based on Verco’s experience, we know that often, heat decarbonisation can be a challenging to tackle because of the range of options available and the risk of a wrong choice or investment locking in a high-carbon emitting solution for years.

But businesses where it’s a material area of energy consumption, shouldn’t rule heat decarbonisation out. As businesses like yours consider switching from gas to electric for heating, look into low carbon fuels or weigh up your next boiler replacement, Verco have developed a range of resources to equip you to make the best decision for your business.

Heat decarbonisation mini guides and webinars

What's clear is that there is still so much potential for businesses to drive further energy savings. It’s exciting to see how much ambition businesses had to make progress between 2024 and 2025.

As businesses look ahead to 2026, whether aiming to make up for lost time, or deliver the next phase of their energy strategy, we’d welcome the opportunity to support you on your journey. Verco’s team of experts are brilliantly placed to help you identify the next opportunity, navigate multiple priorities, and share their perspective on where you could make the biggest energy savings.