A power station has a maximum demand of 15,000 kW. The annual load factor is 50% and plant capacity factor is 40%. Determine the reserve capacity of the plant.

Concept:

Plant capacity factor: 

It is the ratio of actual energy produced to the maximum possible energy that could have been produced during a given period.

\(Plant\;capacity\;factor = \frac{{{\rm{Actual\;energy\;produced}}}}{{Maximum\;energy\;that\;could\;have\;been\;produced}}\)

\( = \frac{{Average\;demand \times T}}{{Plant\;capacity \times 100}}\)

\(= \frac{{Average\;demand}}{{Plant\;capacity}}\)

\(Annual\;plant\;capacity\;factor = \frac{{{\rm{Annual\;kWh\;output}}}}{{Plant\;capacity \times 8760}}\)

The plant capacity factor is an indication of the reverse capacity of the plant. A power station is so designed that it has some reserve capacity for meeting the increased load demand in the future. Therefore, the installed capacity of the plant is always somewhat greater than the maximum demand on the plant.

Reserve capacity = Plant capacity – Maximum demand

If the maximum demand on the plant is equal to plant capacity, then the load factor and plant capacity factor will have the same value. In such a case, the plant will have no reserve capacity.

Calculation:

Load factor = (Average Demand)/ (Maximum Demand) = 0.5

Plant capacity factor = (Average Load)/ (Plant Capacity) = 0.5/0.4

Plant capacity = (0.5/0.4) × 15 = 18.75 MW