Load factor (LF) is defined as the ratio of average load to the maximum demand for a given period of time. Just like demand factor, the load factor is smaller than 1. LF can be defined on the basis of daily, monthly or yearly basis.
Load factor formulas
1 day = 24 hours
1 month = 720 hours
1 year = 8760 hours
Daily LF is a ratio of units generated in a day to MD * 24 hours.
Example 1: The average load (AL) on a certain coal powered station is 3 MW. The MD is 5 MW. Find the LF.
Solution: LF = AL/MD = 3 / 5 = 0.6 = 60%
Example 2: The maximum demand on a thermal power station is 20 MW. The station generates 312 MW in 24 hours. Find the daily LF
Solution: Daily LF = [312 MW]/[20 MW * 24 hours] = 0.65 or 65%
Annual load factor is defined as the units generated per year to maximum demand.
Example 3: A nuclear power station has MD of 50 MW. The station generates 300 * 106 kWh annually. Calculate the load factor.
Solution: 300 * 106 kWh = 300 * 103 kWh
LF = [300 * 103]/[50 MW * 8760] = 0.68 = 68%