a question about industrial tariffs, maximum demand and load factors

[carbon dude oxide]

i know this is more of an electronics forum but i am prety sure that some users here know a thing or two about electrical power

The question i am trying to answer for one of my assignments is 'why are industrial tariffs based on maximum demand and load factor?'

does any one know any good and credible websites or know them selves why energy company's use maximum demand and load factors to calculate how much to charge the consumer?

[SeanB]

Industrial use max demand and power factor as they then charge based on cable size. This provides an incentive for large users to be more flexible in loading, often they will have a few of the bigger continuous operating motor loads done with a synchronous motor that is over driven to get a leading power factor, and this is used to control the overall power factor for the whole plant, or at least large parts that work together. Along with this you schedule large loads such that they are operated in sequence, so you draw a reasonably constant power from the supply network. Some larger plants actually have large gensets that they synchronise to the mains to reduce peak demand as needed to cut the power demand to a level below the point where the supply cost increases a large amount. Often this also is done because the feeders are at max load and they do not want to step up to the next size ( along with all the switchgear, large transformers and the associated digging and larger substations needed) as then the cost per unit also rises.

[carbon dude oxide]

I see, thank you very much.

So i am right in saying that they charge less if the industrial premesis spread there work load over a longer period of time so that there maximum demand is lower, thus allowing te electrical supplyer to install a cheaper / less powerful feeder to the premesis, and because the load is spread over a larger amount of time the stress on the electricity network is reduced.

Is a syncronus motor better then using a power factor correction capacitor?

Also what is genset?