What size inverter do I need in Nigeria?
Inverter size is the first number every seller asks about, and the easiest one to get wrong. Too small and it trips when the fridge or pump starts. Too big and you pay for capacity you never use. This guide shows how to work out the right size yourself so you can check what a seller recommends.
kVA, kW and watts: what the labels mean
Appliances are rated in watts (W). One kilowatt (kW) is 1,000 watts. Inverters are often sold in kVA, which measures apparent power. The power you can actually use, in watts, is the kVA multiplied by the inverter's power factor.
Many inverters sold as 5 kVA can deliver only around 4,000 W of real power because their power factor is about 0.8, while some hybrid units are sold in kW and deliver their full rating. Always read the rated output in watts on the datasheet, and compare inverters on that number.
When a seller quotes a size, ask: how many watts can it deliver continuously, and how many watts for a few seconds? Those two numbers matter more than the kVA label.
How to add up your load
- List everything you want to run during an outage, with its power in watts from the label or manual.
- Decide what can run at the same time. You rarely run everything at once, so many installers assume about 70 to 80 percent of the total.
- Find the appliances with motors: fridges, freezers, pumps, air conditioners, washing machines. They draw a surge, often two to three times their running power, for a moment when they start.
- Add about 25 percent headroom so the inverter is not working at its limit all day. Running near the maximum shortens its life.
- Pick the next standard size above the result.
Our free solar calculator does this arithmetic for you, including the motor surge, and also estimates the battery and panels. Change the numbers to match your own appliances.
What different inverter sizes usually run
| Inverter size | Usually suits | Usually too small for |
|---|---|---|
| 1 to 1.5 kVA | Lights, fans, TV, laptops, router, phone charging. | A fridge together with other loads, any air conditioner. |
| 2 to 3.5 kVA | The above plus a fridge or small freezer. | Air conditioners, large pumps, electric cookers. |
| 5 kVA | A small home with fridge, TV, fans and one 1 HP air conditioner, or a small shop. | Several air conditioners or heavy workshop machines. |
| 7.5 to 10 kVA and above | Larger homes, offices and businesses with several air conditioners or pumps. | This is where a professional load study is worth paying for. |
Motors, surge and why an inverter trips
A fridge that runs at 150 W may pull several times that for a second when its compressor starts. An air conditioner or water pump can pull more. If the inverter cannot supply that surge it shuts down or beeps, even though your total running load looks small.
Ask the seller for the inverter's surge or peak rating and how long it lasts, and tell them which motors you have. Inverter air conditioners and soft-start devices reduce the surge.
12 V, 24 V or 48 V?
The system voltage is the voltage of the battery bank. At the same power, higher voltage means lower current, so thinner cables, less heat and fewer losses. Small inverters of about 1 to 1.5 kVA often use 12 V, mid-size ones 24 V, and larger ones 48 V.
The inverter fixes the voltage, so the batteries you buy must match it. If you may grow the system later, a higher-voltage inverter leaves more room to expand.
Features worth paying for
- Pure sine wave output, which is gentler on fridges, fans and electronics than modified sine wave.
- A built-in MPPT solar charge controller if you plan to add panels, and check its maximum panel voltage and current.
- Hybrid operation so the inverter can charge from the grid or a generator when the sun is weak.
- Overload, short-circuit and temperature protection.
- A battery communication port if you want lithium batteries to talk to the inverter.
- A warranty and a service centre you can reach in Nigeria.
Before you buy an inverter
- Write down your appliances and their watts.
- Find the real continuous watts of the inverter, not just the kVA label.
- Check the surge rating against your fridge, pump or air conditioner.
- Confirm the system voltage and that your batteries match it.
- Ask what the warranty covers and where repairs are done in Nigeria.
- Get the recommended size and the reasons for it in writing.
Listed solar installers and sellers
Businesses are listed free. Some were added from public business directories and some applied themselves; businesses can ask for removal at any time. UpNepa does not verify, recommend or guarantee any business here. Businesses marked Featured pay for extra visibility. Ask for references and get everything in writing before you pay.
No dealers are listed here yet. Are you a solar installer or seller? List your business for free.
Frequently asked questions
Can a 5 kVA inverter run an air conditioner?
Often yes, for one 1 HP air conditioner alongside lights, fans and a fridge, but it depends on the inverter's real wattage and surge rating. Add up the load, including the air conditioner's start-up surge, before you buy.
Is a bigger inverter always better?
No. A larger inverter costs more, uses more power just by being switched on, and needs a bigger battery bank to be useful. Choose a size that covers your real load with some headroom.
What is the difference between an inverter and a UPS?
Both turn battery power into mains power. A basic UPS is built for short backups to protect computers, while a solar inverter is designed to run for hours and to work with solar panels.
How many solar panels do I need for a 5 kVA inverter?
It depends on how much energy you use in a day, not on the inverter size. The inverter sets how much you can run at once, while the panels must replace the energy you use. Use our calculator to estimate the panels for your own load.