Cross Country Solar Race

Dorm writes: "The American Solar Challenge, a 2300-mile cross country solar-powered car race begins on Sunday in Chicago. The 10-day race follows old Route 66 (parallels I-55 from Chicago to St. Louis, I-44 from St. Louis to Oklahoma City, and I-40 from Oklahoma City to Los Angeles) to downtown Claremont, California where teams will cross the finish line on the afternoon of July 25th. If you live along the race route or will be in the area, take a look at the media stop schedule on the ASC site and stop by to see some of the cars during the race. Some teams (including ours, Iowa State) will also be displaying their cars Saturday on the front lawn of the Museum of Science and Industry in Chicago, where the race begins on Sunday." The submitter has more info about Iowa State's entry below.

"Many teams (as well as Iowa State) are using advanced technologies like lithium batteries, near space-grade solar cells, and composite materials such as carbon fiber and fiberglass in their cars. Additionally many of us are utilizing Linux with amateur radio and satellite data phones to monitor weather conditions and to help optimize energy usage.

"We run a LinuxPPC server in our solar car chase vehicle that receives GPS coordinates from a Motorola Encore GPS receiver that is driven by a Lineo uCdimm board running uClinux. The uCdimm board reads in the GPS coordinates and broadcasts the coordinates every second via UDP packets on the ethernet network in the van. The LinuxPPC machine uses the coordinates to track our position and to display upcoming route information (stop lights, turns, road contitions) and to aid our racing strategy. Additionally, the LinuxPPC machine connects to the Internet via a Globalstar satellite phone to periodically download weather maps and forecasts for our current location. We also use GPS and amateur radio with APRS in our other support vehicles to monitor all of our vehicles' positions.

"Most of the code that runs everything is developed in house with C/C++, some of it with the Qt library. Myself and another member of our team will be preparing a detailed presentation in September for our local Unix users group about how we've utilized Linux on our team. If there is interest, I'll post the URL here for that once we've got it prepared.

"A list of other teams competing in ASC next week is available online at the American Solar Challenge web site. Most are university teams from North America, but there are some international teams as well."

Comments

Questions

[Dr_Cheeks]

OK, I've got a few questions about solar-powered cars that I've been wondering about for a few years and I guess this is as good a place as any to ask:

1. Does the race route have to be carefully planned to avoid long tunnels or deep forests?
2. What sort of percentage of maximum speed is attainable on a cloudy day (compared to a sunny day)?
3. Do the cars carry batteries as a backup in case of sudden eclipses etc. that block out the light briefly?
4. If batteries (or some other energy store) are carried, how much running time can be added before the weight of the storage reduces the efficiency to a point where it'd be better to just run off solar power?
5. Do you ever get kids who think it's funny to throw tins of paint at your cars to cover the photovoltaic cells?
6. What sort of a drain on the speed is the Linux-GPS setup?
7. Just how fast do these cars go anyway? Are we talking Smokey and The Bandit or what?

Cheers. I look forward to being enlightened.

Re:Questions

[Phoebus0]

I've been involved in three of these races (Sunrayce '95, '97, '99) for one team, so here's some answers..
1. The route is not planned to avoid anything except really steep grades, and even then there are some pretty steep hills. This is because most of the motors in these vehicles are only about 14 hp.
2,3,4. The vehicles carry batteries with around 4 kWh of power in them. What matters is that with the different battery technologies, the amount of weight is different. 4kWh in lead-acid batteries is about 360 lbs., while 4kWh in Li-Ion is about 70 lbs. On a fully charged battery pack, some of the top cars can run at 55 - 60 mph for 3-4 hours. (That's with no sun at all) A solar car is really an electric car with a solar charging system.
5. Actually, no. Most people just stare and point. If anyone actually tried to throw anything at the cars they would probably be tackled because solar cells are really fragile.
6. The telemetry systems are allowed to be on a seperate battery system from the car's main power, because of the power drain issue and because of the way that the power must be disconnected, and still have telemetry going.
7. Theoretical top speed on the most commonly used motor made by NGM is approximately 72 mph. Not fast by most recognition, but when you are lying on your back 18 inches off the pavement, it seems mighty fast.

Re:What next ?

[Paintthemoon]

Um, get a government not run by guys from Big Oil...

Photovoltaics, not Linux

[standards]

Although it's great to hear about the use of Linux in the race, the real exciting thing going on here is the wide-spread use of new photovoltaics made of integrated conjugated polymers.

http://www.acs.org/nsa/intcong.htm

Sure, not all the teams are using them - but many are, and this is sure to change the dynamics (if not the outcome) of the race.

We're talking 150% greater efficiency here, and at lower cost.

The photovoltaics is the interesting story - after all, we all could guess that many participants are using Linux and GPS!