That's awesome, I was just saying to my mate the other day it'd be nice if the meter ran backwards lol.
@Welshman in a standard ISA atmosphere you only drop 2 degrees per 1000ft, so you'd only be about 3 degrees cooler than sea level (and that's generous to be honest at low level). It'll have an impact for sure, but probably not a huge one.... if, as is likely, you get a bit more of a breeze up there however that'll probably help more than the temperature drop alone with the air moving over the panels keeping them cool. Will be interesting to see how it works out for you.