OV9

I have been gifted some car storage / workshop space, unfortunately it doesn't have any electricity.

There is a supply to a building opposite although it has been disconnected for several years.

I'm assuming paying to get it connected across wouldn't be cheap, and as I'd only be there occasionally not sure it would be worth it.

So I started looking at generators. Sure they're a noisy and not very efficient way to make power, but it would only cost me when I want to use it, and wouldn't have to run constantly.

However, it would need to be able to power a welder which runs off a domestic 13a plug, and possibly a small compressor ( not both at the same time ) but no idea what that means in terms of what size generator I would need

Check the wattage on both the welder and compressor, convert to kVA and buy one rated to that amount. You'll probably find you'll need a 7kVA one. I guess the usual gumtree/fleabay sources if you don't want to invest proper dollar.

You’ll need quite a bit more than the wattage on the items states IME as when motors start up they have a power surge and end up tripping out the fuse on the generator. Generators usually state a working output and can temporarily give more wattage for such occurances but a lot of them just quote the higher wattage level which is wrong.

Could be tricky to find out as most compressors only quote in hp.

My home one pulls just under 15a at start up but under 13 continuous, so it's running off a 3pin 16a plug and socket. Most slightly smaller ones won't pull more than 13a at start up as they run off standard domestic 3 pin plugs with a 13a fuse.

Likewise welders, I have no idea how much power my normal one consumes, but it'll only pull it when striking an arc, most of the time it's sitting there idle. Again it can't ever be more than 13a. I just can't get my head around how outputs and power consumptions are quoted, like you say, headline peak figures aren't a lot of use.

Pop into your local machine mart, probably a good start asking somewhere that sells all the equipment you want to power and the generators to power it

We've bought a few for the races after years of hiring them, but as has been mentioned, best bet would be to talk to someone who knows what they're talking about to understand how powerful a model you'll actually need in the real world.

My limited experience running a variety of stuff off them makes me agree with Mr Jon that you'll need a 7kVA one. There's usually a few always available on Gumtree/FB Marketplace locally.

That's probably the best option, I've been in lots of times over the years but never had to ask any advice so no idea whether they actually know what they're talking about or will just sell me the biggest most expensive one they've got

They sell a 5.5kva one for £600 which would be the max I'd want to spend, if I needed anything bigger it would probably need to be secondhand.