Dr David Snowdon, A/Prof Peter Pudney
The RACV Cruiser Class is about building efficient, practical cars. While it's important for the cars to get to Adelaide by the end of the event (Friday, 2 pm), the outcome of the event is determined by how many people can be transported, for the least amount of external energy. Teams may choose to re-charge their car's battery from an external source, but this will reduce their score. Teams may also choose to transport more people, which will increase the score.
On Day 1 of the 2017 Bridgestone World Solar Challenge we've seen that this is far from a solved problem. Today the configuration of the cars became apparent (see the attached table).
Some cars are capable of carrying five people (allowing for many people to be transported), others are only capable of carrying two (resulting in a lighter car).
Even more varied is the battery mass, and the consequent energy stored in the battery.
Each time a team re-charges from an external source, it is assumed that the team have added a full charge -- increasing their energy use. The size of the batteries varies wildly - STC-2 Nikola carry just 6.1 kWh, compared with 16.3 kWh for the Apollo team.
The last important factor to consider is the 'pace' - the average speed required to arrive in Adelaide by the curfew of 2 pm on Friday afternoon. Teams ahead of the pace may be able to later slow down to conserve energy. Teams behind the pace will need to use more energy to catch up. This pace gives only a rough guide to how teams should be proceeding - teams might also vary their speed to improve the operating efficiency of their car, or to maximise the amount of sunlight they collect.
Eindhoven's Stella Vie dominated Day 1 of the event, arriving at the Katherine control point at 1:29 pm - one minute ahead of the pace - carrying five people over the 322 km distance (1610 person-km), the maximum of any team in to Katherine. All other teams that arrived at the control point were behind by up to an hour, and will need to use more energy to catch up (although the start procedures and Darwin traffic may slowed some teams). The teams carried between one (HS Bochum) and five (Eindhoven) people, with most carrying between two and four. Lodz out-performed several teams who carried more people due to their smaller battery pack (which means the car has used less external energy so far).
While we've now discovered how many people the teams intend to carry, we still do not know how often they will re-charge, and this is key to their efficiency. When the teams arrive at the Daly Waters control stop, around 8:30 am on Monday, their official observer will report whether the team re-charged the car's battery during the night. If teams are able to avoid that external energy use by relying on their solar panel, they'll have a critical advantage in the days to come.
|
Team
|
Name
|
Seats
|
Battery Mass (kg)
|
Battery Specific Energy (Wh/kg)
|
Battery Capacity (kWh)
|
Battery Capacity per Person (kWh/kg)
|
|
05
|
SunSPEC
|
2
|
57.9
|
250
|
14.5
|
7.2
|
|
09
|
PrISUm
|
4
|
45.0
|
250
|
11.3
|
2.8
|
|
11
|
HS Bochum SolarCar Team
|
4
|
58.8
|
250
|
14.7
|
3.7
|
|
14
|
Flinders Automotive Solar Team
|
3
|
118.7
|
250
|
29.7
|
9.9
|
|
23
|
University of Tehran Solar Car Team
|
4
|
96.6
|
250
|
24.2
|
6.0
|
|
30
|
Clenergy Team Arrow
|
2
|
61.0
|
250
|
15.2
|
7.6
|
|
35
|
IVE Solar Car Team
|
2
|
30.3
|
250
|
7.6
|
3.8
|
|
40
|
Solar Team Eindhoven
|
5
|
30.5
|
250
|
7.6
|
1.5
|
|
42
|
TAFE SA
|
2
|
119.0
|
125
|
14.9
|
7.4
|
|
45
|
Lodz Solar Team
|
5
|
29.0
|
250
|
7.2
|
1.4
|
|
49
|
STC-2 Nikola
|
2
|
24.6
|
250
|
6.1
|
3.1
|
|
75
|
UNSW Solar Racing Team Sunswift
|
4
|
42.3
|
250
|
10.6
|
2.6
|
|
94
|
University of Minnesota Solar Vehicle Project
|
2
|
27.0
|
250
|
6.8
|
3.4
|
|
95
|
Apollo Solar Car Team
|
2
|
65.2
|
250
|
16.3
|
8.1
|
