David Benton wrote:hmm , i'm not so sure power factor and phase balancing are that small a problem . they certainly go to great lenghts to retcify them here , and charge alot if they're not .But your correct , Nellie Bly is not talking about power factor.
A large power customer will pay an avaliability charge for thier peak load , it doesnt really matter how often they need it , or what proportion of thier average load it is . The peak load is what the power company has to provide equipment that can handle that load for , it doesnt matter if its once a year , thats what theyll charge you for . Then there is the charge for power actually used , then possibly penmalites for power factor , and phase imbalance .
Our industrial and large commercial customers pay a demand charge based on the peak demand (generally in a 15 minute interval, but see the below special provision for traction power) for the billing month measured in kilowatts. The demand readout is reset to zero monthly when the meter is read, or remotely for remotely read meters. The other major component of the bill is the energy charge for all energy used in the month, measured in kilowatt hours.
We can refuse to serve a customer whose power factor is beyond a certain variation from unity. Customers with that issue generally have compensating devices such as capacitors to offset inductive loads.
As a point of interest, our largest (maybe our only for heavy rail; JCP&L has several supply points) supply point for New Jersey Transit (NJT) traction power is the Meadows substation which is fed in flow-through configuration by two 230kV lines. NJT owns the substation (bus, stepdown transformers, protection system, etc.) and we own the wires to the points of interconnection at each end of the substation.
Our electric tariff is here
http://www.pseg.com/companies/pseandg/s ... tariff.pdf
The two traction power provisions in the above are as follows:
Large Power and Lighting Service
BILLING DETERMINANTS:
Monthly Peak Demand:
The Monthly Peak Demand for each time period shall be determined by the registration of a demand meter furnished by Public Service. The customer’s Monthly Peak Demand in any month for each time period shall be the greatest average number of kilowatts delivered by Public Service during any thirty-minute interval for secondary distribution voltage customers and during any fifteen-minute interval for primary distribution voltage customers. Where the use of electric service is intermittent or subject to violent fluctuations, Public Service may base the customer’s Monthly Peak Demand for each time period upon five-minute intervals in lieu of intervals hereinbefore set forth. Where electric service is supplied for traction power to a rail rapid-transit system, for the purpose of determination of Monthly Peak Demands, the hours 8 A.M. to 10 A.M. and 4 P.M. to 7 P.M. shall be included in the Off-Peak time period, and Public Service shall base the customer’s Monthly Peak Demand for each time period upon the greatest average number of kilowatts delivered by Public Service during any single coincident hour-ended sixty-minute interval during each time period, in lieu of fifteen minute intervals.
High Tension Service
BILLING DETERMINANTS:
Monthly Peak Demand:
The Monthly Peak Demand for each time period shall be determined by the registration of a demand meter furnished by Public Service. The customer’s Monthly Peak Demand in any month for each time period shall be the greatest average number of kilowatts delivered by Public Service during any fifteen-minute interval. Where the use of electric service is intermittent or subject to violent fluctuations, Public Service may base the customer’s Monthly Peak Demand for each time period upon five-minute intervals in lieu of intervals hereinbefore set forth. Where electric service is supplied for traction power to a rail rapid-transit system, for the purpose of determination of Monthly Peak Demands the hours 8 A.M. to 10 A.M. and 4 P.M. to 7 P.M. shall be included in the Off-Peak time period, and Public Service shall base the customer’s Monthly Peak Demand for each time period upon the greatest average number of kilowatts delivered by Public Service during any single coincident hour-ended sixty-minute interval during each time period, in lieu of fifteen-minute intervals. Where traction power is supplied at high voltage (230,000 volts) and such power is being provided during a limited period to supplant power normally supplied by another utility, that limited period shall be excluded for the purpose of determining Monthly Peak Demand.