What Is Electrical "Load Factor" Formula

Electrical (demand or power) Load factor is a measure of the utilization rate, or efficiency of electrical energy usage. It is the ratio of total energy (KWh) used in the billing period divided by the possible total energy used within the period, if used at the peak demand (KW) during the entire period. Demand Load Factor is usefull in qualifing the benefits of demand control and battery energy storage strategies.

Thus, The Electricity Demand Load Factor Calculation is:

Demand Load Factor = KWh/KW/hours in the period

To calculate your load factor take the total electricity (KWh) used in the month and divide it by the peak demand (power)(KW), then divide by the number of days in the billing cycle, then divide by 24 hours in a day. The result is a ratio between zero and one.

An Electric demand Load Factor Calculation Example

Monthly Energry Use 4000 KWh

Monthly Peak Electric Demand 35 KW

Days in the Month 30

Hours in a Day 24 days

Power Load Factor = 2000/35/30*24 = 15.9%

(You are getting killed on your monthly electric bill.)


Another beneficial metric is the Electrical Load Duration Curve. And for a real understanding of the electrical power load factor we use Time of Use (TOU) Distribution analysis. (you need to drop us a note for this explaination.)

What does Your Load Factor mean

Potential Benefit from Demand Control
Load Factor >0.75 0.50 - 0.75 0.35 - 0.50 0.20 - 0.35 0.10 -0.20 < 0.10
Benefit of Demand Control Limited Benefit Possible Benefit Yes Depends Upon Return Good Potential Excellent Potential Easy Money

If your load factor ratio is above 0.75 your electrical usage is reasonably efficient. If the load factor is below 0.5, you have periods of very high usage (demand) and a low utilization rate. Low load factor customers would benefit from a peak demand control system or from a Battery Energy Storage System to distribute electrical usage out over longer intervals of time and smooth the peaks. For those unfortunate enough to have a very low load factor; you need to call Power Planet.

Low load factors, such as, below .4, contribute significantly to the overall monthly electric bill in the form of demand charges. These demand charges are listed on the bill as coincident demand , facilities demand, and summertime related demand. If these peak demand charges are adding up to a lot of money, there is a solution.

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