Last month, we headed to Stuttgart with our solar electric car to set the record straight when it came to aerodynamics. Results are in, and Lightyear 0 is in line for the title of most aerodynamic production car in the world. And in history.
Aerodynamics are important around here, being key to developing long range (solar) electric cars. Wind tunnel testing has now confirmed that Lightyear 0 will be the most aerodynamic production car in history, with a breakthrough drag coefficient (Cd) of 0.175.
Last year, real-world tests put us on track for the badge of most aerodynamic production car. More recently, we completed rigorous safety system, functional, misuse, crash, durability, robustness and multiple homologation tests. Each comprehensive test plays a critical role in delivering a safe and reliable car, bringing us closer to the finalised assembly instructions we’ll hand over to Valmet Automotive later this year.
Today, we mark another technological milestone as the journey closes around groundbreaking wind tunnel tests.
Spending the day at FKFS wind tunnel, our aerodynamics team validated Lightyear 0's ambitious aerodynamic requirements with a history-making drag coefficient; after a sequence of tests put Lightyear 0 in pole position for streamlined design.
The smaller the drag coefficient, the bigger the range
Lightyear 0’s energy consumption, and therefore its efficiency, depends on three key elements: the aerodynamics, rolling resistance and heating system.
Aerodynamics is a major energy consumer, with air resistance increasing to the power of two with velocity. In fact, at highway speeds, aerodynamics account for around 60% of overall energy consumption. Most electric car drivers will have felt the sting of restricted range, especially at higher speeds.
Lightyear 0 tackles the challenge with a design that minimises air resistance and therefore achieves a very low drag coefficient; all while keeping lift force and its balance to ensure a smooth ride for drivers. A good (low) drag coefficient means a more economical car that consumes less energy and, as a result, can drive further on one charge. Our drag coefficient is a huge contributor to the overall efficiency that places Lightyear 0 as a market frontrunner.
To deduce the drag coefficient and gather a fuller picture of the car's aerodynamic properties, Lightyear 0 went through four different and comprehensive tests in Germany:
Pressure measurements — achieved by pressure taps connected to a sensor and attached to multiple areas of interest on the car to determine the pressure distribution all around the car's surface.
Aeroacoustic measurements — performed with microphones placed both outside and inside to capture noise caused by airflow around the car
Force measurements — the core activity, designed to calculate drag and lift forces, and therefore the different force coefficients. The car was placed under different conditions of yaw, pitch and airspeed to evaluate its sensitivity.
Wake measurements — attained with grid structures fitted with probes and placed in different positions on the car to measure velocity and pressure in areas of interest. They give the clearest overview of airflow around the car.
Onsite in Germany, Lightyear aerodynamics test lead, Federico García López said: “With the wind tunnel test, we validated all our aerodynamic requirements. We took our car and tested it against realistic road conditions using the certified WLTP procedure. That test served as our validating run, as it gives a perfect representation of the car’s aerodynamic capabilities”
A design sketched by airflow
It’s our firm belief that energy wasted through air resistance could be better spent on extending journeys. We’ve built in that vein from the beginning, with a clean approach that finds inspiration in the natural world.
Look at nature's geometry, and you’ll find ingenious design down to finite detail. From landforms sculpted by oceans to leaves that nurture and roots that nourish. A fox’s eye, a bird’s wing. Just as nature forms its champions to thrive in challenging worlds, we designed our car holistically for unprecedented performance in everyday life.
But, in doing so, we faced trade-offs. We began with a blank slate and a bold ambition to marry a purposeful, aerodynamic design with sleek and stylish aesthetics. Striking that balance is no easy feat. It’s the same reason the automotive world hasn’t yet put aerodynamics at centre stage in car design, mostly prioritising the statement curves and recognisable shapes that give each vehicle its identity, instead.
Our approach went against the grain. We wanted a beautiful and unique design both led and shaped by airflow, and we found it in Lightyear 0: the first production car in the world to realise this revolutionary balance.
Learnings for Lightyear 2
All research, testing and development plied into Lightyear 0 gives Lightyear 2 a headstart, not only in developing an even more efficient and capable car, but in making it accessible with a competitive market price. It’s our goal to bring it to the world by the end of 2025.
Every technological achievement that Lightyear 0 makes becomes an invaluable inheritance to Lightyear 2. And groundbreaking aerodynamics are no exception.
Aerodynamics domain expert, Annemiek Koers, said: “Next up, a WLTP certification test will run on the test track to validate and certify the efficiency of the whole car. With the wind tunnel test, we made sure all our aerodynamic requirements were met and we are quite confident that the WLTP certification result will be the expected one.
Federico added: “With this testing of today, we not only broke the record with Lightyear 0, but we also already started working on our Lightyear 2 model.”
“With Lightyear 2, we’ll build upon our key learnings and innovations to achieve a mass-market car that sets new standards in efficiency. And aerodynamics will form a large part of that.”
For Lightyear, the potential of solar electric mobility is as broad as the horizon. In the same way the sun’s power pours over our planet infinitely, we strive to create cars that move through it effortlessly
As our world moves to more sustainable energy sources, Lightyear is driving the development of clean mobility in the automotive industry. By enabling electric vehicles to be scalable for everyone, everywhere, we will accelerate the sustainability transition for a positive impact on our planet.
Our technology is engineered to enable a clean future. Starting from scratch and using a holistic design approach we developed an ultra-energy-efficient long-range solar car. Our technology redefines performance with what truly matters: efficiency.