Green NCAP Unveils New Electric Vehicle Cold Weather Testing
Green NCAP, a green vehicle assessment program, is introducing a new ‘warm start’ cold ambient test to provide more consumer-friendly estimations of electric vehicle (EV) driving range in cold weather conditions. This new test, alongside the existing cold ambient test, aims to give consumers a more accurate understanding of how heating impacts an EV’s energy consumption and, consequently, its range.
The Challenge of EV Range and Climatisation
The average energy consumption of EVs has traditionally been measured without considering the energy used for heating. This omission can lead to significant discrepancies between advertised and real-world driving ranges, sometimes reducing range by as much as half. Currently, EVs undergo the Worldwide Harmonised Light Vehicles Test Procedure (WLTP) for energy consumption during a standardized driving cycle. However, according to Dr. Aleksandar Damyanov from Green NCAP, these tests don’t always accurately reflect real-world conditions.
“It has become increasingly clear that comparing vehicles’ average energy consumption can be very misleading,” Damyanov states. Considerations such as temperature, driving style, and road conditions heavily affect energy consumption and driving range. This variability is a major factor in “range anxiety,” a concern for potential EV buyers, particularly those transitioning from internal combustion engine (ICE) vehicles.
The Impact of Heating on EV Performance
Unlike ICE vehicles, which can utilize waste heat from the engine, EVs rely on the battery for heating. This means that the energy needed to warm the vehicle comes at the cost of driving range. As Damyanov explains, “With EVs we have seen that the main contributor to a vehicle’s energy consumption differing from what has been officially declared, is the impact of climatisation.”
The initial ‘cold ambient temperature test’ developed by Green NCAP simulates harsh winter conditions. In this test, vehicles are subjected to -7 degrees Celsius for an extended period before testing. The heating is then turned on to 23 degrees Celsius. This test reveals significant differences between the WLTP results and real-world energy usage. For instance, vehicles in recent tests showed an average type approval consumption of 16.7 kilowatt-hours (kWh) per 100 kilometers, whereas the cold ambient test averaged 31 kWh per 100 kilometers. The results show an 86% increase; however, there can be cases where the driving range is halved.
Introducing the ‘Warm Start’ Test
To provide a more comprehensive understanding of EV performance, Green NCAP is adding a new test in 2025. This ‘warm start’ cold ambient test simulates a scenario where the vehicle has been kept in a garage overnight, maintaining a warmer starting temperature. The new test mirrors the environment of the cold ambient test with the same low temperatures but starts with a preheated vehicle. According to Damyanov, “The combination of both tests allows us to make a much more consumer-friendly estimation of the total driving range of an EV under cold conditions.”
Initial findings indicate that the cold ambient test uses approximately 25% more energy than the new warm start test. For example, a tested vehicle used 29 kWh per 100 kilometers during the cold start test, but only 22.5 kWh in the warm start test.
Industry Response and Future Developments
CLEPA, the European Association of Automotive Suppliers, values the efforts of Green NCAP: “Cold-weather testing is pivotal for electric vehicles, as it provides consumers with accurate insights into real-world performance. At the same time, it acts as a catalyst for manufacturers, offering crucial data that drives continuous improvements.”
EV manufacturers are actively working on improving heating efficiency. Innovations like heat pumps and battery thermal management systems (BTMS) help to mitigate energy consumption. Furthermore, manufacturers are exploring technologies that deliver heat directly to occupants, such as seat and steering wheel heating, to improve overall efficiency.
Green NCAP plans to release test results from the 2025 protocols in the first half of the year. These tests include the new warm start cold ambient test along with a new insulation test. As E-mobility Europe summarizes,”As Green NCAP assessments highlight the real-world efficiency of different EV models, manufacturers will be incentivised to develop smarter and more efficient climatisation systems, leading to broader consumer acceptance and a faster transition to electric mobility.”
