Demand for cooling in London has risen by 5% every year since 1980, which is among the highest increases seen anywhere in the world, according to a new model by energy researchers.
Countries in northern Europe such as the UK were built for colder temperatures than what climate change is now bringing, making them traditionally unprepared for the extreme heat that will become more common in future summers.
The growing intensity of heatwaves means more energy will have to be used to keep buildings cool, accompanied by greater costs and higher greenhouse gas emissions.
Last year’s 40C heatwave caused sales of air conditioning units to skyrocket, and this will likely continue as these heatwaves become more frequent, the researchers from Imperial College London said.
Along with colleagues at TU Delft, they have developed a model called Demand.ninja to map how weather changes impact energy consumption by the hour at any geographical scale.
It is intended to be used by planners to model future scenarios using new technologies or behaviours and to help them plan infrastructure upgrades such as adding heat pumps or electric vehicles to the grid.
The model can also be used to show how potential behavioural changes impact energy consumption. For example, the researchers calculated that if every building in Europe turned down the thermostat by 1C, it would save 240 TWh of natural gas a year – around a sixth of historical imports from Russia.
Nathan Johnson of the Centre for Environmental Policy at Imperial, said: “Since Russia’s invasion of Ukraine, Europe has been racing to reduce gas consumption to avoid shortages and lower consumers’ bills.
“If all buildings across Europe lowered their temperature by 1C, this would cut the cost of imports by 22 billion euro (£18.9 billion) per year and cut CO2 emissions by nearly 50 million tonnes per year: a win-win-win for energy security, affordability and the climate.”
Details of the model, which is freely accessible to anyone, are published in the journal Nature Energy.
It uses 40 years of Nasa data on local air temperature, humidity, solar radiation and wind speed to estimate how warm or cool it feels when inside a building.
This is then used to predict how much energy would be used to regulate that temperature using measurements at the national, regional and individual building level.
The researchers said their model could also help answer global questions such as how much energy the world needs for everyone to feel comfortable, countering both extreme heat in summer and extreme cold in winter.
Despite rapid changes in summer temperatures, extreme cold kills far more people than heat – 4.6 million compared to 500,000 – and represents 10% of global deaths.
Heat becomes fatal once the daily average temperatures reach 27C and the model can show how often and where this has happened over the last 40 years to help planners understand where solutions are needed, the researchers said.
Lead researcher Dr Iain Staffell said: “Accurate modelling of the impacts of weather on energy supply and demand is critical to decarbonising power systems.
“We are making the Demand.ninja open for anybody to use, which we hope will open up new possibilities for researchers, for example when looking at how to operate 100% renewable grids, or the impact of heat waves and heat pumps on peak electricity demand.
“This isn’t just about energy, it’s a major global health issue.
“More than five billion people experience over 100 additional cooling degree days per year compared to a generation ago.
“A successful global energy transition will depend in part on understanding where, when and how much energy is required to close the gap in heating and cooling.”