The “frying pan of Spain” shows how cities can manage extreme heat
The city of Seville is used to extreme heat, so much so that it is often called “Pan of Spain.”
The summer afternoons, the air is so hot that the streets of this historic city in southern Spain become empty, because simple breathing outside becomes extremely difficult. And it could be even worse in the future.
With climate change, heat waves occur earlier in the year and become more intense. In June, a record summit of 46 C Was recorded in Huelva, near the Portuguese border, confirming that 2025 had the warmest recorded in Spain on June.
By 2050, Seville could record the summer Peaks of 50 C and a 20% reduction in precipitation,, According to a study conducted by Eltiempo.esA network of new Spanish weather. The city therefore has no choice but to adapt.
By developing several solutions around the innovative use of water, Seville is now at the forefront of cities that have found ways to face increasing heat and have recently been appointed winner of the 2025 edition of Mission, a competition between Spanish cities on climate transition.
On the Isla de la Cartuja, the Seville district which welcomed Expo ’92, a group of researchers has established an old technique to cool the interior urban areas.
Called Qanat, this technique was invented by Persians about 3,000 years ago To improve irrigation, lower ambient temperatures and provide drinking water to animals in arid regions.
“Basically, we use this old and proven technique to adapt it to our 21st century,” said MarÃa de la Paz Montero Guérrez, project researcher called Cartuja Qanat.
Located about 20 to 200 meters below the surface of the desert, the system consists of a series of underground channels built on a slight slope which transport higher water to lower altitudes by gravity.
Two qanats were installed in Seville on each side of an agora, or rallying, which is the size of two football fields. During the night, groundwater is cooled by naturally lower temperatures. Solar energy pumps propelled water cooled to the surface during the day, where it is then pushed by vertical vents, which allows it to reduce the soil temperature by six to 10 degrees Celsius.
You probably know what it is to go through a heat wave or a record. But it can be more difficult to wrap your head around the average temperature to a figure increases compared to climate change. Naël Shiab of CBC guides you through a new tool that projects how hot summers could get in the cities of Canada by the end of the century.
Guérrez says that they “modernized the Persian technique by integrating rainwater and electricity generated from solar panels. The entire project is therefore completely self -sufficient without counting on technologies with high energy intensity”.
The space – which includes an agora and an amphitheater – has become a real oasis, which welcomes the inhabitants who come to take a refreshing break or for sporting activities and events.
“If you come here in the middle of the agora, you can feel fresh air and breathe normally, while the outside is impossible in the afternoon,” said Guérrez. “This model is really proof that there are lasting solutions.”
The vegetation planted on the interior walls of the building, the white exterior which reflects the heat and the orientation of the input doors also help to reduce the temperature.
Since its implementation in 2021, the project, which costs around Five million euros To install, attracted visitors from around the world curious to know more. The delegations of California, Germany and Dubai came to be inspired.
“This Persian technique could technically be established everywhere,” said José Sánchez Ramos, professor of energy engineering at the University of Seville.
However, one of the main challenges remains convincing developers to include this solution in their projects, as it requires additional costs, from construction to maintenance.
Bioclimatic schools
Another water-based cooling solution helps students cope with high temperatures far beyond summer, because the Andalusian regional government has decided to implement bioclimatic air conditioning systems in schools.
“It is a system that works in a very simple way with the evaporation of water,” explained Manuel Corties Romero, director general of the Andalusian public agency for education.
To do this, an adiabatic cooling machine must be installed on the school roof. This system, which works with solar panels and water, absorbs hot outside air and then cools it inside the machine. During the process of transforming the liquid water into a gas, the evaporated water moistens and simultaneously cools the air flow.
Fresh air is then distributed throughout the school through many vertical vents. This technique allows the interior temperature to be reduced to 12 C, even when the windows are open.
It has been implemented in more than 450 schools in the Andalusia region – of which 131 around Seville – and each new school is built with this system.
“We really see the difference in the behavior of the students,” said one of the employees of the Ies Cristóbal de Monroy, a secondary school in the suburbs of Seville. “Before, there were a lot of behavioral and attention problems because of the heat, but now this system makes all the difference.”
The cost of installing the Cristobal ies of Monroy, which has 1,300 students, was half a million euros.
“It is almost the same price as the air conditioner, but the difference is the cost of the monthly electricity bill. It is about a tenth of what a normal system would be, because this system requires minimal electrical power,” said Romero.
He said it can be reproduced elsewhere. The challenge is to explain this technique, because people may seem skeptical at first.
“At the very beginning, nobody really knew it, and the parents were a little skeptical because they did not know this specific technique,” said Romero. “Seeing the results, everyone is now convinced of the comfort that this technique brings to students.”
Adapt urban spaces
Seville also implements solutions to adapt urban planning to heat waves, street blinds to reducing asphalt surfaces or using light and permeable urban surfaces to limit the effect of the urban heat island.
This last phenomenon occurs when heat is preserved by Materials and surfaces then radiating in the surroundingsThis means that the city experiences much warmer temperatures than neighboring rural areas.
Cruz Roja Avenue is at the heart of this strategy. The Life Watercool project, which costs approximately 3.7 million eurosaims to alleviate urban heat by evapotranspiration.
The avenue was transformed by an artery animated into a pedestrian area with shadow which makes it possible to collect runoff water, stored in a tank and then pumped in public spaces.
“This groundwater cooling system allows us to irrigate new trees that create shadow but also to use water for a fountain in a public square. It also allows us to distribute fresh air via vertical vents in the public square and in the courtyard of a neighboring school,” said Teresa Palomo Amores, Life Watercool project manager.
The location of the fountain has also been studied to allow the cooling of the hot air which will reach the square. “The union of all technologies will allow us to reduce the temperature by three or four degrees in this square.”
One of the objectives of the project, which will be fully operational next fall, is to implement several solutions that can help cities anywhere in the world to adapt to a global warming.
“It is a very long process with many steps, but it is not impossible,” said Amores. “First of all, you must develop removable coverage to reduce solar radiation and adapt to the trees that will develop. Then you have to put a sidewalk with high reflection, which will reduce the soil temperature, unlike asphalt. And later, the entire water system must be organized.”
Researchers will now study how the cooling of this public square could also cool the surrounding residents.
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