Proper generator sizing guide is a business continuity decision of the utmost importance. In industrial, commercial, or residential buildings, too-small units result in equipment breakdown and business disruption, and too-large units result in operating expenses and inefficiency.
We at TechnoPower value these challenges and provide expert consultation to ensure that your generator investment meets your true power demand. We customize our expert solution to your specific operating condition, whether a heavy-load factory, data center, or large residential compound.
What is generator sizing, and why is it crucial?
Generator sizing is the method of finding the appropriate size (measured in kW or kVA) that your generator needs to safely deliver a load to your equipment and operations. Proper sizing of a generator ensures:
- Improved functioning during a power failure
- Preventing Overloading and Premature Failure
- Improved fuel economy and fewer emissions so there is The Diesel Fuel Consumption Chart.
- Compliance with safety and regulatory standards
Risk of Inaccurate Sizing
Under-sized Generators: Overheat, shut down, or destroy highly sensitive equipment
Oversize Generators: Waste fuel is more expensive, and is prone to low-load-induced wet stacking
Key Factors in Generator Sizing
1. Overall Load Requirements
Determine the total power (kW/kVA) needed by your equipment. Make a note of every appliance and its starting and operating wattages. This is a critical step in sizing properly.
2. Load Type: Inductive, Motor, or Resistive Load
Note the type of load; motor loads like compressors and HVAC demand more starting power.
3. Single-phase and Three-phase Power
Commercial and industrial uses usually require three-phase power for a consistent, balanced power supply.
4. Runtime and Autonomy
Determine how long you need the generator to last during a power outage. This will dictate fuel tank size and the type of generator unit
5. Location and Altitude
Generators operate in different conditions. Derating is needed for high altitude or hot weather to size it ideally.
Industry-Specific Sizing Standards
Industrial Sector
Factory and manufacturing facilities need sizing in the areas of equipment cycles, motor loads, and essential production continuity. A good example is a steel mill needing a 1000 kVA generator running continuously for 24/7 and even needing to synchronize it with an identical unit during maintenance periods.
Power cuts in this sector can cause massive business losses due to production lines shut down and machinery being damaged. Peak loads need to be estimated, and the buffer capacity increased.
Commercial Sector
Offices, malls, and shops require backup in the areas of lighting, HVAC, elevators, and IT infrastructure. For instance, the 300 kVA generator will serve a medium-sized office building that hosts central air conditioning, elevators, and server racks adequately.
For retail and hospitality, the preservation of the customer experience during a power outage is imperative. Power loss can result in POS downtime, lights out, and in-building comfort problems, all of which work against business reputation.
Apartment complexes
For apartments, luxury villas, or a secured compound, it must supply water pumps, lights, air conditioners, and appliances. It might require a 150 kVA generator for a compound of 10 luxury villas, depending on simultaneous loads and load factors.
Homeowners need seamless transition during outages, and in places like the Middle East, where hot summer conditions require round-the-clock AC, it's a necessity. TechnoPower assures quiet residential generator running and emission compliance.
How Is Generator Power Calculated?
The power of an electric generator is calculated based on the total electrical load it needs to support. This power is typically measured in kilovolt-amperes (kVA) or kilowatts (kW). To determine the right generator size, you first calculate the combined power requirements of all connected devices (such as air conditioners, lights, refrigerators, pumps...), then add a safety margin of about 20% to handle unexpected surges.
Simple formula:
Generator power (kW) = Total load (kW) × 1.2
If your devices are rated in amperes (A), you can convert to kilowatts using this formula:
kW = (Voltage × Current × Power Factor) ÷ 1000
Example: A device using 20 amps at 220 volts with a power factor of 0.8
→ kW = (220 × 20 × 0.8) ÷ 1000 = 3.52 kW
In this case, you would need a generator with a capacity of at least 4.5 kW to ensure safe and reliable operation.
How TechnoPower Helps You Get It Right
We provide comprehensive generator sizing analysis, which includes:
- Field power survey using clamp meters and real-time monitors
- Measuring and analyzing loads using data logging systems
- Standby vs. prime vs. continuous generators: Recommendations Diesel, gasoline, or hybrid generator type choice based on TCO (Total Cost of Ownership)
Struggling? Call TechnoPower for a no-obligation consultation
Let our technical experts guide you in the right direction. We give complimentary business consultation to organizations in Saudi Arabia, the UAE, and the GCC region.
Case Study: Generator Sizing for Logistics Hub
We recently had a large warehousing and logistics facility in Riyadh require generator back-up power due to utility grid failure. Peak loads of up to 600 kW were measured by our survey team on conveyor belts and motor and refrigeration loads.
We proposed a synchronized set of 400 kVA auto-start and ATS system diesel generators, utilizing 20% redundancy and maximizing fuel economy. Result: Zero downtime on two unexpected shutdowns, and a fuel cost saving of 16% due to precise sizing.
Additional Factors in Selecting a Generator
Automatic Transfer Switches (ATS)
These units detect a loss of power and switch automatically to the generator, in a perfect solution for mission-critical use.
Noise Level and Enclosures
Noise-critical or residential uses can use containerised generators or silent generators. Sound-reduction canopies reduce the sound below 75 dBA.
Fuel storage and refilling procedures
Long-term operations are associated with high-capacity external tank planning and the supply of fuel on a schedule. Monitoring fuel levels remotely avoids interruption of the service.
Compliance and Certifications
Generators must carry local standards and safety approvals (e.g., SASO, CE, ISO 8528) to operate legally and safely.
Why use TechnoPower?
- Over 15 years of industrial, commercial, and residential work experience
- Advanced power requirements engineering capabilities
- Strong After-Sales Service, Spares, and AMC (Annual Maintenance Contract) plans
- Used by top contractors and governments across the GCC
- Tailored products in containerized, silent, or mobile generator systems
Not just a valuable resource, a good generator is a guardian of the business. Correct sizing is the first step towards continuous productivity and economies of scale. Count on TechnoPower to guide you through the process accurately and professionally.
Call us today for expert generator sizing to power your successes.