Power Generation/Variable Load/Part1

Maximum demand ( MD ):

The greatest demand of load on the power station during a given period. The highest peak on the power station load curve.

Demand Factor ( Dem.F ):

Ratio of maximum demand to connected load. this is usually less than 1.

$Dem.F={\frac {MD}{Con_{.}Load}}$

Average load ( MD ):

This is the average of loads occuring on the power station in a given period.

Daily average load:

Average of loads occuring on a power station in 1 day (24Hrs).

$={\frac {Total_{.}of_{.}units(in_{.}kWh)}{24Hrs}}$

Monthly average load:

Average of loads occuring on a power station in 1 month (24Hrs x No. of days).

$={\frac {Total_{.}of_{.}units(in_{.}kWh)}{24Hrs\times days}}$

Yearly average load:

Average of loads occuring on a power station in 1 year (8760Hrs).

$={\frac {\sum Total_{.}of_{.}units(in_{.}kWh)}{8760Hrs}}$

Load factor ( LF ):

The ratio of average load to maximum demand. typical ≈ less than 1. This is the measure of the effective use of the power station.

$LF={\frac {Load_{ave}}{MD}}={\frac {Output_{Annual}(in_{.}kWh)}{(Capacity_{Installed}\times 8760Hrs)}}$

High LF = Low MD = Low plant capacity = Low cost per unit generated.

Diversity factor ( DF ):

The ratio of the sum of all individual maximum demands on the power station to the Maximum demand on the station. Consumer maximum demands donot occur at the same time thus maximum demand on power station will always be less than the sum of individual demands.

$DF={\frac {MD_{individual}}{MD_{On_{.}station}}}$

High DF = Low MD = Low plant capacity = Low investment capital required.

Plant capacity factor ( PCF ):

The ratio of actual energy produced to the maximum possible energy that could have been produced on a given period.

$PCF={\frac {kWh_{perannum}}{Plant_{.}Capacity\times 8760Hrs}}$

This indicates the reserve capacity of a plant. From these we can see that:

$Units_{.}generated=MD\times LF\times 8760Hrs$