World Solar Challenge

[HungLikeJesus]

Here are some calculations to get started:

Typical peak insolation is about 1000 W per square meter. Current solar module efficiency is about 12% (but this could go much higher with some of the multi-junction cells under development). Typical capacity factor for solar is about 15-18% (unless you're in PDX, apparently) - you can calculate your expected annual output by multiplying the nameplate rating by 8760 hours per year and multiplying that by the capacity factor.

Now you just need to know annual load to determine the required surface area of the panels (of course, you also need to de-rate for the average angle of incidence, since the panels won't be perpendicular to the sun most of the time). This assumes that you have sufficient battery capacity to store the electricity produced.