When choosing a generator, one of the most important parameters is its power. It determines whether the equipment will be able to provide stable operation of all necessary electrical appliances during a power outage. Insufficient power will lead to overload and generator shutdown, while too much power will lead to unnecessary purchase costs. Therefore, it is important to correctly calculate the required equipment performance.
NTT Energy recommends choosing a generator based on your home’s actual energy consumption, the number of devices connected, and potential future load increases.
Why is it important to calculate power correctly?
Every household appliance consumes a certain amount of electricity. Many devices require significantly more power during startup than during normal operation. This is especially true for refrigerators, pumps, air conditioners, compressors, and power tools.
If the generator cannot provide the required starting power, the equipment may operate erratically or not start at all.
Therefore, when choosing a generator, not only the constant load is taken into account, but also the starting currents.
How to calculate the required power
To determine the appropriate model, it is recommended to follow a few simple steps:
- Make a list of all devices that need to work at the same time.
- Determine the power of each device.
- Take into account increased consumption when starting equipment with electric motors.
- Add the obtained values.
- Add a power reserve of about 20-30%.
This calculation will allow you to select a generator that will operate without overload even under maximum load.
Example of energy consumption of household appliances
| Electrical appliance | Average power |
| Home lighting | 200–500 W |
| Fridge | 200–800 W (including start-up) |
| Gas boiler | 150–300 W |
| TV | 80–200 W |
| Computer | 300–600 W |
| Water supply pump | 800–2000 W |
| Electric kettle | 1800–2200 W |
These values are approximate. It is recommended to review the technical specifications of each specific device before purchasing.
Which generator is suitable for different houses?
Energy needs can vary significantly depending on the size of the home and the number of appliances.
For a small country house, a generator with a capacity of up to 3 kW is usually sufficient if only the basic household appliances need power.
For a private home with heating equipment, a pump, a refrigerator, lighting, and several additional devices, models with a capacity of 5–7 kW are most often chosen.
If you need to power a large cottage, workshop, or home with powerful electrical equipment, you may need generators with a capacity of 8–10 kW or more.
NTT Energy specialists always recommend performing calculations individually, since identical operating conditions are practically never the same.
Common mistakes when choosing
When purchasing a generator, homeowners often make the following mistakes:
- only the nominal power of the devices is taken into account;
- forget about starting currents;
- choose equipment without power reserve;
- they buy a generator that is too powerful unnecessarily;
- do not take into account the possible connection of new equipment in the future.
Preliminary load calculations and consultation with specialists will help avoid such mistakes.
Is it worth buying a generator with a power reserve?
A small power reserve is considered optimal. Typically, 20–30% above the rated load is sufficient. This reserve ensures stable generator operation, reduces the load on the engine, and allows for additional electrical appliances to be connected if needed.
However, having too much reserve is also undesirable. A generator that constantly runs at a low load is less efficient and significantly more expensive.
Conclusion
Properly sized generator power is essential for a reliable backup power supply for your home. This requires considering the total load of all connected devices, starting currents, and a small capacity reserve. This approach will avoid overloads, extend the life of the equipment, and ensure uninterrupted operation of your appliances in any situation.
If you’re unsure which generator is right for your home, NTT Energy specialists can help you calculate your load, select the optimal model, and answer all your questions about selecting and operating the equipment.
