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Aussie Team Smashes Land Speed Record For Solar-Powered Cars
snowdon writes "A record which has stood since 1987, set by General Motors, has been broken (YouTube video) by a university team. The land speed record for a solar powered car was 78km/h, and now stands at 88km/h despite the cloudy conditions... If only Doc Brown had used the metric system!"
that it was only making about one point twenty one kilowatts.
The car in TFA didn't have a battery. The solar panels are connected directly to the drive train/motor(s).
The difference is the WSC cars are allowed to use a battery - the rules for the Guinness World Record specify solar power only.
In the 2009 WSC the UNSW car reached 103km/h with a LiPol battery, but that was removed for this attempt to comply with the Guinness rules.
What part of "a well regulated militia" do you not understand?
Both vehicles have about 25kG of batteries. The difference: Sunswift 4 was operating only off solar power, whereas Nuna was in a race where batteries were not only allowed, but required (the race was over several days.) Nuna had both solar and battery power for acceleration.
Please help metamoderate.
which everyone who visits here assures me is so much brighter than their part of the world.
Thanks to ozone depletion we get more energy out of the sun.
Seriously its the dry air. It absorbs less solar radiation so more hits the ground.
http://michaelsmith.id.au
I can tell you the World Solar Challenge rules. (The SunSwift car depicted looks like it follows WSC Challenge class rules.) There are safety requirements for roll cage, braking, steering, wiring, circuit breakers. The driver's eye-line must be at least 70cm above the road. There's a maximum angle the driver is allowed to lay back at. There's a max of 6 square meters of solar cells. The battery is a max of 5kW.h. (This is a trivial amount of energy compared to the energy budget over the whole challenge, but is tactically useful for hill climbing, clouds, etc.)
It looks like the only change they made for this Guinness challenge was to remove the battery pack.
Yes, it looks like the 2003, 2005, 2009 WSC challenge winners (Nuna, Nuna, Tokai) could have knocked this record over, just by removing the battery pack and getting Guinness certification. Doing some rough maths, UNSW's pace is still pretty competitive: the speeds you see listed for WSC course competition do not figure in the time the cars spent charging their batteries each dawn and dusk, after racing ends at 5pm for the day and before it begins at 8am the next day.
It would be awesome if we could have made it thinner -- the wing is there as the lowest-drag shape that we can put around the other components in the car -- suspension, steering, driver, etc. Its designed to be a lifting body because of the ground effect which would otherwise result in a negative lift. The cambered wing counters the negative lift generated by the ground effect.
Welcome to Planet Earth, where everyone uses the metric system - except for Americans.
I could be wrong, but usually the speed tests are done in both directions with the end speed being the average of the two values. This prevents people from taking advantage of things such as wind and/or angle to the sun.
Yes that is standard practice.
http://michaelsmith.id.au
There's quite a bit of truth to what they are telling you. As MichaelSmith alluded to, it's mostly because of the lack of airborne moisture, particulates and pollution cf. the comparatively wetter, more land-covered, more populated northern hemisphere.
In fact as an Australian that went overseas to the US and Europe for the first time as a 20 year old, it's one of the first things I noticed when I stepped off the plane. The sky is often a light, hazy blue, close to ~white~ near the horizon, even on a cloudless day. Put simply, it's the greater humidity in your atmosphere (with some contribution from both man-made pollution, and natural particulates such as pollen etc). OTOH as soon as you are >50km away from the coast in Australia, a sunny sky will be a deep, deep blue, with no discernable difference in colour between 'straight up' and 'at the horizon'. Not to say you can't get days like that elsewhere (desert regions would be like this world-wide), but this is the norm over most of Australia. Where I live (which is in the inland of Australia), I have never seen that 'white haze' that is common in the northern hemisphere sky.
Of course that viciously blue sky, although nice for solar power and photography, is a curse in many ways. Low average humidity makes us the driest inhabited continent, and we also have the highest UV irradiation on earth (and the highest rates of skin cancer as a consequence). The UV index used worldwide was obviously developed in the northern hemisphere since the highest category 'Extreme' starts at 11+ (and is supposed to represent the 'top few days' in a year). The scale is kinda useless in Australia since EVERY day is 'Extreme' (our normal summertime UV here is typically in the 13 to 15 range, and I've seen higher): http://en.wikipedia.org/wiki/Ultraviolet_index
The sun only produces so much energy per unit area on earth. As I understand it, this vehicle uses solar power directly (without storage). Really, you could probably only hope for another order of magnitude or so before reaching the theoretical limit of perfectly efficient solar energy to kinetic energy transfer, and that upper limit is generous.
My point is solar power usage in situations like this has a definite upper limit of efficiency, which we're not *that* far away from.
At the time the movie was made, the giga prefix wasn't in popular use except in certain scientific fields, and scientists disagreed whether it should be pronounced with a hard g or a j-sound. Jiggawatt was a perfectly correct pronunciation which simply went out of fashion.
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