Factories charged per kVA?, why not get PF and charge in kWh?

[JohnW2]

Also even if they only have a reading taken every 30 minutes, maybe the meter would also send back the average kWhs consumed in that half hour; ...

As I said, I don't know much about these contracts, but, as westie has said, I think there are several components to the billing. I think they usually are, just like a domestic/commercial consumer, charged for (continuously) metered kWh (or kVAh), with or without PF surcharges, but they are also potentially charged additionally according to their peak demand, particularly if they exceed the agreed maximum capacity of the supply.

Think of a silly domestic analogy... If I told my supplier that I needed about 11.5kWh per day, they would be happy to just give me a normal supply and charge for it, 'per kWh', in the normal way. If I then 'expanded' my requirement, by explaining that what I actually needed was about 300A (at 230V) for 10 minutes each day, and very little for the rest of the day, then they might decide on some 'non-standard' way of charging me for the supply!

Kind Regards, John

 

[JohnW2]

The transmission lines are on OS maps.

Indeed they are, and probably a good few of the substations etc., but I think that probably falls far short of the 'wiring diagram of the grid' which I think he was hoping/asking for!

Kind Regards, John

 

[EFLImpudence]

If i see a transmission line going across a motorway or a local substation, can I find it on a map what covers the nation.)

OS maps cover the nation.

 

[Dave54]

Certainly when I was involved, and it is 40 years ago nearly, the energy used was paid for in the normal way by the unit. Going over the maximum demand for any half hour period incurred a hefty penalty. Enough to cause quite a panic, and as I said earlier, to start switching equipment off.
Also as said, the suppliers don't like sudden heavy loads at random times. I'm pretty sure that if you went to the supplier and said "I need 300A for 10 mins a day" then they would say. "OK, but it has to be at 3:00am." I know that the big sync. motor I mentioned earlier was never started at times of peak demand on the grid.
I do know that a well known outside contractor for that type of work was working on the comms of the generators of that set, they were "inching" the motor, to get at the segments. God knows what the starting load was direct on the 11kV. The large, oil filled starting reactor (inside a sub station type tank) was rated at two starts an hour IIRC, so say nothing of the breakers for the switching.

While the OS maps certainly show the power lines etc. There might be a perceived issue with national security in publishing a full diagram of what is where. I don't know for sure though it's just a thought.

 

[Lectrician]

A company we work with used to exceed their MD quite often, and every month would be levied with a charge of around £3 for doing so. This was on top of their £25k monthly bill. They decided it was better to do this than pay to upgrade the supply, as this involved some huge costs! They ran the risk of the DNO pulling the plug (literally), but did this for a few years until they were ready to increase the supply.

The OS maps show many of the overhead 132kv and above lines, but not the 33/11kv ones, and certainly not local 400v. Obviously no underground either.