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Generator Size Formula:
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The generator size calculation determines the required capacity of a natural gas generator based on the electrical load and the efficiency of the generator. Proper sizing ensures reliable power supply without overloading the generator.
The calculator uses the simple formula:
Where:
Explanation: The formula accounts for the fact that not all the generator's capacity is available as useful power due to efficiency losses.
Details: Correct generator sizing is crucial for ensuring reliable power supply, maximizing fuel efficiency, preventing overload conditions, and extending equipment lifespan.
Tips: Enter the total electrical load in kW and the generator efficiency as a decimal (e.g., 0.85 for 85% efficiency). Both values must be positive numbers.
Q1: What's a typical efficiency for natural gas generators?
A: Most natural gas generators have efficiencies between 30-45% for smaller units and up to 50% for large industrial units.
Q2: Should I add a safety margin to the calculated size?
A: Yes, it's common practice to add 10-20% to the calculated size to account for future load growth and transient peaks.
Q3: How does this differ for standby vs prime power generators?
A: Prime power generators are typically sized closer to the calculated value, while standby units may be sized slightly smaller since they won't run continuously.
Q4: What other factors should be considered in generator sizing?
A: Motor starting currents, harmonic loads, ambient temperature, and altitude can all affect the required generator size.
Q5: Can this calculator be used for other fuel types?
A: The basic sizing calculation applies to all generator types, but efficiency values will differ for diesel, propane, or other fuels.