Electric car air conditioning and range: Do electric cars get stuck in summer traffic jams?

During the Whitsun holidays, holidaymakers were stuck in continuous traffic jams on Austria's A10 Tauern Autobahn for over five hours at a time – despite bright sunshine and correspondingly high temperatures in the car. Newcomers to electric mobility are wondering whether using the air conditioning for hours on end will kill the range and whether it's better to sweat in the car with the windows open to avoid being stranded on the motorway without power.

First, let's take a look at the technology. Air conditioning systems in electric cars work no differently than those in combustion-engine cars. At their heart is the air conditioning compressor. The difference: While the air conditioning compressor in combustion engines is usually driven by a belt, the compressors in electric cars have their own electric motor. The air conditioning compressor in a car works similarly to the compressor in a refrigerator. It draws in a special gas, the refrigerant, and compresses it – this makes it hot and under high pressure. This hot gas is then cooled in a cooler (the condenser), where it becomes liquid and cools the air inside the car via a heat exchanger.

The air conditioning systems of electric cars therefore use two major power consumers: the air conditioning compressor and the motor for the ventilation system. Anyone familiar with the considerable consumption of home air conditioning systems may therefore wonder whether the interior cooling system might drain the drive battery in a very short time. First of all, the all-clear: This fear is unfounded. The ADAC (German Automobile Club) tested why this is the case in a new climate chamber, which will be inaugurated in 2024, in which a Tesla Model Y was "baked" for eight hours with the air conditioning switched on.

The eight-hour test simulated a typical summer day with temperatures up to 35 degrees Celsius. UV lamps also provided varying levels of sunlight to create realistic conditions. The Tesla tested started with a 60 percent battery charge and the auxiliary climate control set to 20 degrees Celsius. Despite extreme heat – temperatures of up to 45 degrees Celsius were measured on the dashboard, and the windshield even heated up to over 60 degrees Celsius on the outside – the interior remained comfortable: At head height and in the footwell, the temperature was consistently below 25 degrees Celsius.

Energy consumption is important in this context. According to the ADAC (German Automobile Club), the air conditioning system's power consumption remained constant at around 1.2 to 1.5 kilowatts. Over the entire period, the total consumption was around 12 kilowatt-hours, which, in the case of the Tesla, adds about 8 kilometers of range per hour—a very good result. Since the design and function of air conditioning systems in electric cars are similar, the automobile club assumes that these results can be transferred to other models.

In summary, it's essential to keep a cool head in summer traffic jams and let the air conditioning in your electric car do its thing. This is not only better for your health and well-being, but also has minimal impact on the driving range. As a rule of thumb, the ADAC test shows that using the air conditioning in summer traffic jams "sacrifices" less than ten kilometers of driving range per hour. A small electric car battery can also manage this. And it's better for the environment, too: For cars with combustion engines, energy consumption with the air conditioning running in summer traffic jams is 1 to 1.5 liters of fuel per hour. That corresponds to 10 to 15 kilowatt hours.