Thanks Phil.
I didn't understand a word of the Watts, ohms, amps, etc but it's good to know that I will be able to run 8 x 240v items at once with 130m of extension leads.
I will probably put them up on poles to keep them away from the sheep. Easier than digging a trench!
Oh, and I'll get a power surge thingy
If I can, I'll buy one extension lead each month. It'll take me a while to build the obs, so I won't need power up there yet.
Which is better? 10amp leads or 15 amp leads? (depending on prices too)