Guide to Determining Generator Power and Energy Requirements

Using a commercial generator and working with the best generator brands in this context, is crucial for the continuity of your business plan. In the case of a power outage in your facility, it provides emergency situation power to run critical systems such as elevators and security.

Moreover, it minimizes work and data loss while diminishing computer system malfunctions. Nonetheless, choosing the right electrical generator to meet your energy demands relies on a series of factors. When looking at different generator types, choosing among the best generator brands and understanding which is the best for your requirements can be difficult.

What to Keep in Mind When Determining Energy Requirements?

  • The power consumption of electrical devices: Determine the total power consumption (in watts or kilowatts) of all the electrical devices that the generator will feed. You can generally find this information on the labels or user manuals of the devices.
  • Starting Current: Some machines may use higher power when starting. Keep this under consideration to ensure that your generator meets the required total startup power.
  • Secondary Power Requirements: You may need extra power in emergency situations or sudden load increases. Keep this in mind when you look at the capacities of the best generator brands.
  • Fuel Type and Efficiency: Determine what kind of fuel your generator will run on and evaluate the costs as well as the accessibility. Also make a detailed calculation of total fuel consumption.
  • Operation Period: Determine how long your generator will need to run. For longer operation periods, consider factors such as fuel capacity and overall durability.
  • Portability or Fixed Installation: Decide whether you need a portable model or a fixed installation. This will determine the generator placement and ease of use.
  • Total Power Consumption: Calculate your total power requirements by adding together the energy requirements of all electrical devices. This figure represents the minimum power of the generator.

What is Generator Power?

In broad terms, generator power is the maximum electrical power a generator can produce in a given period. It is generally expressed in kilowatts (kW) or kilovolt amps (kVA). The power of a generator depends on the design features of the generator engine and alternator, the fuel type and operating conditions.

Generator power represents rated output power that is determined according to various factors. Some of these factors are engine type, fuel type, engine speed, efficiency, load capacity and operating conditions. Power is generally the maximum power capacity as determined by the producer, and this capacity represents the maximum power the generator can run comfortably over a certain period of time.

Generator power is also the generators capacity to operate under a given load. However, some models feature “instantaneous” or “augmented power” that can provide high output for short periods of time. These show that the generator has a capacity to handle short-period high loads.

How to Calculate Generator Power?

Generator power is the measurement of the electrical energy that a generator can produce. It is usually expressed in unit watts of electrical energy and various factors are calculated.

*Power (Watts)=Current (Volts) x Intensity (Amps)

This formula using Ohm’s Law (P=VI) is the basic approach to calculating the power of a generator. However in practice, other factors may need to be considered to calculate generator power.

Moreover, generator power is generally defined in two ways: Rated power and maximum power. Rated power is the maximum power a generator can safely produce continuously. Maximum power is designed to meet high short-term energy needs and it is not recommended to run the generator for long periods at this level.

Other factors should be considered when calculating power for various generator types. The power factor represents the ratio between active power (actual power) and the reactive power (power determined by the phase difference between current and amps).

Each model is different, so it makes sense to study the technical specifications and information provided by the manufacturer in detail.

Which Features Change the Power of Different Generators?

Generator power can change according to design, technical specifications and purpose of use.

Rated Power:

This is the maximum power determined in design that can be produced safely for continuous operation. This figure determines the general capacity of the generator.

Maximum Power:

If electrical devices in the system require short-term high energy, maximum power in a generator represent the power needed to meet this requirement.


Output voltage affects the power of a generator. Low voltage can mean low power, so it is important to determine the correct voltage according to the application requirements.


Output current determines the power produced. A higher current will increase total power.


Output frequency is measured in terms of hertz (Hz) that is the periodic repetition of electrical energy waves. This is an important parameter in electrical systems and affects generator power.

Fuel Type and Efficiency:

Generators run on different type of fuel (gasoline, diesel, natural gas, hydrogen etc.). Fuel type and efficiency have an effect on power production.

Power Factor:

The power factor represents the difference between active and reactive power. A higher power factor may define a more efficient use of energy.

Operating Conditions and Ambient Temperature:

Operating conditions and ambient temperature can affect performance. The generator’s cooling capacity is important especially in high-heat environments.

The power of top generator brands are determined on the basis of the combination of these factors and design features. Keep these in mind to make the best choice according to your requirements and application needs. Feel free to get in touch with us for a power assessment of your specific requirements. Check out our catalog for our product line with some of the top names in the business.