Why Heatwaves Are Really A Hidden Energy Management Problem

Jul 6

In June 2026, the UK had its hottest June day on record so far, with temperatures exceeding 36°C in parts of England and Wales. The current heatwave has caused widespread disruption, including transport delays, school closures and cooling system failures in hospitals.

For many organisations, the immediate impact of hot weather is obvious: air conditioning runs for longer, refrigeration systems work harder and electricity consumption increases.

What's less obvious is what heatwaves can reveal about the way a building uses energy.

A Growing Issue

According to the UK Parliament Library, heatwaves in the UK are becoming more common and are expected to become more frequent as the climate continues to warm.

The Met Office has also reported that extreme heat events are becoming more frequent, longer-lasting and more intense as global temperatures rise.

For businesses, this means that unusually hot weather is no longer an occasional operational challenge. It is becoming a recurring feature of the energy landscape.

Heat drives electricity demand

The relationship between temperature and electricity demand is well established.

As temperatures rise, cooling demand rises with them. Offices, retail premises, warehouses, data centres and manufacturing facilities all require additional energy to maintain safe operating conditions.

The International Energy Agency reported that in 2024, more than 40 countries representing almost 70% of global electricity demand recorded new peak demand records during heatwaves.

In other words, heatwaves are not just a weather event. They are also an energy demand event, which has knock-on effects for business cost and sustainability.

The difference between higher consumption and wasted consumption

As a result of all the above, many businesses expect energy consumption to increase during extreme heat.

The more useful question is whether it increases by the amount it should.

Two buildings with similar occupancy levels, operating hours and weather conditions can produce very different energy profiles during a heatwave.

This could occur for any number of reasons, for example:

HVAC systems running outside occupied hours
Simultaneous heating and cooling in different zones
Faulty sensors or controls
Poorly configured building management systems
Equipment that has gradually drifted away from optimal performance

These issues may have only a minor impact during mild weather. During a heatwave, they become much more visible.

For example, an industrial cold store may have a refrigeration system that is consuming 30% more energy than it should due to poor controls, equipment degradation or incorrect setpoints. On a cool day, that inefficiency might amount to an extra 300 kWh of electricity. During a heatwave, when the refrigeration system needs to work much harder to maintain temperature, the same underlying inefficiency could result in 600 kWh or more of unnecessary consumption. The problem hasn't changed, but the cost of the problem has.

Why peak demand matters

Energy consumption is only one side of the equation.

Many organisations are also exposed to charges linked to peak demand, particularly larger commercial and industrial sites. When temperatures rise sharply, cooling equipment often starts simultaneously across a site, creating short periods of exceptionally high demand.

Without visibility of half-hourly or sub-meter data, these events can be difficult to identify. The first indication may be a higher-than-expected bill weeks later.

So what should your businesses actually do?

Monitoring energy data in real time makes it possible to see when peaks occur, which assets are responsible and whether they could have been avoided.

Granular energy monitoring and automation can help organisations respond more effectively to periods of extreme heat by:

Identifying which systems are driving increased consumption
Detecting equipment faults and control issues earlier
Reducing unnecessary operation through automated scheduling
Managing peak demand events that can increase energy costs
Comparing performance across sites and assets
Prioritising energy efficiency projects using real consumption data

Ultimately, managing energy during a heatwave requires visibility. The more detailed the data, the easier it becomes to identify inefficiencies, automate responses and understand where energy is being consumed.

As we always say at GridDuck: you can’t manage what you can’t measure; everything starts with data.

To learn how energy monitoring can benefit your business, please contact us at hello@gridduck.com.

Gregor Hoefter