Stella Vie (2017)
Class | cruiser |
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Length x Width x Height | 5.0 m x 1.65 m x 1.22 m |
Weight | ~380 kg |
Occupants | 5 |
Budget | €350,000 |
Back view
Front view
Here's a side view
What's interesting here is that in the past, Eindhoven has typically had a flat roof, but for this car, they've decided to go with a curved roof (presumably for aerodynamics). Typically teams have tried to avoid curves in their designs due to manufacturing tolerances (and the possibility of accidentally creating compound curves) and the ability to better normalize your array. They've probably done analysis on their design and determined that the gains there were not worth it.
Aerodynamics
Frontal Area | |
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Drag Coefficient |
Stella Vie supposedly has 9% less drag than Stella Lux, and 20% less drag than the original Stella.
Dynamics
Front track | |
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Rear track | |
Wheelbase |
Performance
Top Speed | 130 km/h |
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Average Power Consumption | 15.88 Wh/km @ 70 km/h (computed from WSC 2017 stats) |
Range | 1000 km (solar + battery) |
Note: At WSC 2017, they used 48 kWh of energy (while carrying an average of 3.4 passengers) to drive 3021 km, driving at an average speed of 70 km/h.
Note: According to Ericsson sponsorship post, they cite using 48 kWh / km when carrying 3 to 5 people at a time when travelling at 69 km/h, which seems really high.
Note: According to RACV, they can cruise at 70 km/h solely off the energy generated by the solar panels (implying that they consume at most 1.2 kWh at 70 km/h).
Array
Cells | Sunpower E60 |
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Efficiency | 24.3% |
Modules | |
Cells | 326 |
Area | 4.9878 m2 |
Power | 1212 W |
They use interdigitated back-contact (IBC) cells, which prevent shading losses from the metal grid of wires at the front side connect to the negative contacts of the cell in typical cells. In IBC cells, the positive and negative contacts are all positioned at the rear side of the cell.
They have a prototype encapsulation by DSM Advanced Solar, which supposedly made their array safer to touch without damaging the encapsulation.
Battery Pack
Battery Chemistry | |
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Manufacturer | |
Nominal cell capacity | |
Pack Configuration | |
Number of Cells | |
Nominal Pack Voltage | |
Nominal Pack Capacity | |
Pack Energy | 12.5 kWh |
Temperature Sensors | |
Cell Balancing | |
Cooling |
They use 18650 form factor cells.
Their battery box
Dimensions | |
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Material | |
Weight | 50 kg |
Motors
They used 2 Marands.
Motor Controllers
Telemetry
Composites
They used pre-preg carbon fibre from Delta-Preg (mostly Twill Weave, with some Unidirectional) with honeycomb core in many places for extra strength.
The shell of Stella Vie is made up of four large molds. One for the roof, one for the bottom and two for the sides. The molds are presumably milled by themselves.
Extras
Like previous cars, they use Ericsson’s Solar Navigator in-car app that provides aggregated data on weather, traffic and car performance. However, this iteration also includes topography and elevation data, which was applied to ensure the car was in the sun as much as possible, both on the road and when parked. It's basically a heavily-customized version of a commercial app that Ericsson provides (and their Connected Urban Transport platform) as part of their partnership.
This application also considers (near) real-time information from public traffic information, other road vehicles, and connect sensors to traffic light infrastructure. They have a screen that indicates to drivers when they should brake and brake or accelerate (in order to improve driving efficiency). Moreover, the app takes into account traffic light timings, and notifies the driver how long they have before the light changes.