My Maplins meters arrived today, they do exactly what they say in their tin. It would be useful in the display was backlit, but you can't have everything.

Looks like I'm not using as much power as I though. My two servers (big Dell PowerEdge and old Dell desktop), routers and switches only draw about 180W.

A question about watts and kwh. Is the relationship between them a simple one ?

Is it just a case that if I am drawing 180W constantly that I am using 0.180 kwh every hour ?

Oh and a Linux kernel build draws an extra 15W...