Sorry for taking so long. Alan you are correct Sir, Electrical Principles for the Electrical Trades J.R.Jenneson 2nd Edition has it as kWh, also all answers relating to kiloWatts has it as kW. Thank you for your patience Alan. Brendan
Get a list of the amperage of your gear, and gear you want, work out how much use you expect, what items will possibly be running at the same time, wheather running continuos or only part time. Dont forget lighting especially any flood lighting.
The biggest unknown will be how much growth you expect? When you finally work everything out in only a few years you will at least want double what you need now, if you are planning a long stay expect to want tripple the power you want now. This may seem unrealistic atm, and while costing you extra, now is the cheapeast time to increase the cable size and the switchboard size.
Weld an earth bolt inside base, then you have made allowances for an earth, up to him to get a sparky to run an earth to it. Not saying this is enough to meet the manufacturing requirements of where you are. (Enter a whole new ugly world). gromet idea is good too. Nice job BTW