Business Green: Have you ever wondered how much carbon you could save if you plonked a wind turbine in your company car park? If you have, then you might be interested in a nifty iPhone app from Danish wind energy firm Vestas. Vestas Weather app uses GPS coordinates from your iPhone to calculate how much energy one of its latest V112 3MW machines would generate and how much carbon dioxide you could save if you installed it where you’re standing — right there, right then. Despite the fact …