Tessie Hartjes, VP Marketing of Lightyear

JEC Composites Magazine : Tell us about the Lightyear adventure and the goal behind it. How did this project, not without challenges, come about?
Tessie Hartjes: The history of Lightyear lies in the World Solar Challenge. A team from the Eindhoven University of Technology competed and became world champions by building a 5-seater solar cAar that was able to drive between 1,000 to 1,500 km on a single battery charge. The first time they did that was in 2013. Around that time, the first EVs with a range of 100-250 km took to the streets. Most im­portantly, during the race they noticed that the gasoline cars had to stop at the station to refill whereas the solar car could just go on driving. The experience and technology achievement from this race, breaking some of the barriers for EV adoption (range, charging, and in the end costs), made the founders of Lightyear realise that there is actually a large potential for solar cars in the commercial market. Due to its long range, low charging needs and small bat­tery (making the car relatively cheap), pro­ducing a mass-market solar car can address the customer needs much more efficiently than EVs that try to provide a lot of range by using a lot of battery, in result leading to a very charging infrastructure dependent vehicle. Lightyear aims to do the opposite: build cars that only have to charge once or twice a year, and can be driven based on pre-existing infrastructure (the sun and normal power sockets). We want to leap­frog the charging infrastructure and scale worldwide so we can provide clean mobili­ty for everyone, everywhere.

JEC Composites Magazine : Your latest prototype, Lightyear One, just smashed a record for range on a single battery charge. Can you tell us more about how the prototype works and the condi­tions of this test?
Tessie Hartjes: The car was tested on a test track in Germany where we drove 8.45 hours, com­pleting over 339 laps. It was quite a windy day with intermittent clouds, and temper­atures ranging between 20-24 Celsius. We drove at a constant speed of 85 km/hr.

From the World Solar Challenge, we de­veloped a Vehicle Performance Model to accurately predict the energy consumption of the vehicle in different circumstances. For the challenge this was very important, you were only allowed to charge once every 3,000 km. So, you want to make sure the battery is as empty as possible when you charge it. Our prediction models are therefore extremely detailed. An important part of this test was to validate our models and to validate the performance of our technologies developed in-house such as the in-wheel motors, inverters, and solar roof. Within the vehicle design, we have focussed on making it very efficient, devel­oping our own powertrain, designing the car to be very aerodynamically optimised (with a drag coefficient of less than 0.20 – the best in the market) and together with our partner Bridgestone we have devel­oped tyres with very low rolling resistance.

For the first run, we were very happy with the results! The next step is to perform more tests, such as at higher speeds and in different weather conditions.

JEC Composites Magazine : What are the key factors that contributed to the success of this project? (i.e., optimising existing technologies vs. creating a disruptive solution)
Tessie Hartjes: The design philosophy combined with our in-house developed technologies. We have chosen to focus on efficiency instead of, for example, acceleration. We take this effi­ciency to the next level within every design choice we make and therefore can deliver a car that uses 80% less energy from the grid and 2-3 times less energy per km.

Our experience from the World Solar Challenge has been essential to the execu­tion of both.

JEC Composites Magazine : Why did you choose to explore solar energy, out of all the other solutions currently available in terms of mobility? Tessie Hartjes: It offers independence. You can just park your car and it will charge. Solar cells have become increasingly cheap and they provide you clean, free and hassle-free energy. With our first model, in the Neth­erlands, you can already drive for months during the summer without charging. Our goal is to deliver a car that in 15 years’ time will ensure that you only need to charge once or twice a year, for every average driver in Europe.

JEC Composites Magazine : How do composite materials contribute to Lightyear One performance? Do you expect use to increase in future models?
Tessie Hartjes: We are using glass fibre as a supporting material beneath the solar roof and recycled carbon fibre composites in a couple of other places such as the body panels. These materials are still in development and we definitely expect to leverage the increased performance in the future to a greater extent. Another interesting and exciting area to watch is additive manufacturing of composite materials, which offers great opportunities to reduce weight and manufacturing complexity.

JEC Composites Magazine : Which partners helped you fulfil this dream? (Investments, technological and commercial partnerships)
Tessie Hartjes: Our customers and investors indeed. Most of our customers are also considered our investors because we all want to make this happen. Alongside this, we have recently added SHV as an investor. We are happy to work together with some great partners like Bridgestone, Valmet Automotive, LeasePlan as well as some smaller innovative partners.

JEC Composites Magazine : Reducing carbon footprint is an issue that is critical to the automotive sector. At Light­year, how have you envisioned balancing this equation? What solutions have you developed to reach your current outcome?
Tessie Hartjes: In Lightyear’s sustainability approach, we focus strongly on minimising CO₂ emissions, both during the use of the car (very energy-efficient with solar on board) and in the design and manufacturing process. Developing and designing cars with a view to reusing parts and materials is another important environmental concern. In the social field, we focus on a diverse, international team of well-trained people, who work together in a safe, healthy and energetic environment on our mission to provide “Clean mobility, for everyone, everywhere”.

JEC Composites Magazine : What are your next steps towards commercialisation?
Tessie Hartjes: Our first important milestone will be to get our first model on the road and delivered to our customers, starting from next summer. After that, we will introduce a mass-market model for a purchase price of far below €50,000, planned for 2024. This model will also be delivered in the US and Asia, so commercially we are focussed on building our brand and growing inter­nationally.

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