# World, Writing, Wealth discussion

6 views
World & Current Events > Solar challenge race begins in Australia

message 1: by (last edited Oct 08, 2017 01:20PM) (new)

Is this super-cool or what?
Solar-powered cars from more than 30 countries around the world have begun a biannual 3,000km (1,865-mile) race from Darwin to Adelaide, north to south across the centre of Australia. This year marks the 30th anniversary of the competition.

(http://www.bbc.com/news/world-austral...)

message 2: by (new)

Actually, I suspect it will be super hot. They won't be wasting energy on air conditioning, and central Australia is not noted for being chilly.

message 3: by (new)

Temps look to be around 90 degrees during the day. Pretty hot! Why don't they do this when it's cooler? Something to do with the angle of the sun?

message 4: by (new)

Scout wrote: "Temps look to be around 90 degrees during the day. Pretty hot! Why don't they do this when it's cooler? Something to do with the angle of the sun?"

My guess is, the stronger the sun, the better for solar power. However, you could realise that this is relatively cool, near the equinox. Central Australia can become an oven around February.

message 5: by (new)

Looking at these cars, you have to see that solar panels take up so much space. Any chance of creating smaller, more efficient panels?

message 6: by (new)

Scout wrote: "Looking at these cars, you have to see that solar panels take up so much space. Any chance of creating smaller, more efficient panels?"

Not really, the problem is the power from sunlight, which is about 1.3 kW per square meter at noon, and it drops off proportional to the sine of the angle. (A horsepower is about 3/4 of a kW). So you see, if you want a car with a hundred horsepower, you need an awfully of square meters.

message 7: by (new)

So, no way in the future to somehow amplify sun power? There must be a more efficient way than these big panels. Maybe use something like magnifying glasses that concentrate the rays.

message 8: by (new)

Yes, but not for a car. In my novel, "Red Gold", I suggested warming Martian settlers' domes for growing plants by having giant mirrors in space that focused the sun's light on a limited area to warm it up (Mars has average temperatures of about 80 degrees below Centigrade), but for a car, having a lens stuck above it as big as a football field would be a bit difficult for driving (and for parking). The best way to use solar power would be to charge up batteries at home, say, and just drive an electric car.

message 9: by (new)

Scout wrote: "Temps look to be around 90 degrees during the day. Pretty hot! Why don't they do this when it's cooler? Something to do with the angle of the sun?"

It's actually only Spring here :-) Darwin is pretty warm most of the year, being in the tropics, while Alice Springs in the middle will be warm during the day, (and very dry), while cool at night. Adelaide will be variable at this time of year.

And of course it's 3000km from Darwin to Adelaide, and the climate zones are very different, so it's a bit of a compromise - it'd be too cloudy in winter, and too hot in summer.

message 10: by (new)

Thanks, Leonie. That makes sense.

Ian, the magnifying glass idea was off-the-cuff from a person with no scientific background. You gave me a laugh with "having a lens stuck above it as big as a football field would be a bit difficult for driving (and for parking)."

message 11: by (new)

My son did two solar races here in the US. Those cars were cool and looked like spaceships. The driver would have to lie flat with their head propped up to drive.

message 12: by (new)

Belle wrote: "My son did two solar races here in the US. Those cars were cool and looked like spaceships. The driver would have to lie flat with their head propped up to drive."

@_@ where were those races? Did his team build their car too?

message 13: by (new)

Lying flat while driving is another reason why this sort of vehicle is not going to be anything more than a stunt.