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

Re:Questions

[Anonymous Coward]

1. Does the race route have to be carefully planned to avoid long tunnels or deep forests?

The race is carefully planned. not so much for tunnels and forests, but more for safety. Avoiding interstates, and avoiding small towns (i.e. traffic) are both good ideas, although seem to be in conflict with each other. It takes the race organizers the better part of a year to plan the route.

2. What sort of percentage of maximum speed is attainable on a cloudy day (compared to a sunny day)?

The speed is not a function of sun (at least not directly). These are electric vehicles, powered by batteries. The more sun, the slower you drain your batteries.

3. Do the cars carry batteries as a backup in case of sudden eclipses etc. that block out the light briefly?

Yes.

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?

The rules of the race limit the amount of batteries you can carry (ex: Li-ion=30kg). After the first few days of a race, teams typically run only off the sun, using power from the batteries only in the morning/evening/cloudy periods.

5. Do you ever get kids who think it's funny to throw tins of paint at your cars to cover the photovoltaic cells?

Kids (and adults) are always a risk. They never realize that the paper thin silicon they are about to touch is worth more than them. For this reason, when they are on display, the cars are never left unguarded. I haven't heard of any intentional vandalism though.

6. What sort of a drain on the speed is the Linux-GPS setup?

I beleive this setup was in the support van, not the solar car. The rules allow auxiliary batteries (replacable) to be used to power telemetry equipment, so this is not an issue.

7. Just how fast do these cars go anyway? Are we talking Smokey and The Bandit or what?

Honda (WSC 96) attained a maximum speed of 138km/hr. I beleive this is still the record. More typical max speeds are between 100-115 km/hr. Typical average race speeds are around 70-85 km/hr although can reach higher speeds depending on the terrain.

Rob
Midnight Sun Solar Car Team

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.

...to downtown Claremont, California

[gowen]

where their vehicles will be commandeered by the state and used to provide an alternative energy source to PG&E.

Exxon

[CaptainZapp]

from the exxon-hates-these-people dept.

Actually, you could be quite right here, Michael. In the wonderful, corporate-sponsored brainwas^H^H^H^H^H^H^H^H educational world of Disney Worlds Epcot there is an Exxon sponsored "History of Energy" run.

Allthough it's a fun run, it nearly made me barf. The kiddies are told The "history" of energy purely from the sponsors perspective and agenda. The fact that energy could actually be conserved and used responsibly was just ridiculed in one snide side remark.

It was then, when I realised that Disney is a truely and absolutly evil corporation, unmatched even by M$.

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!