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Solar system for home in Nigeria: what size do you need?

Start with the appliances you need during a power cut, how long you use them and how you will recharge. A bedroom count or an inverter’s kVA alone cannot answer those questions.

By Bankole Emmanuel · Updated 24 September 2026 · Worked planning example, not an installation quote or equipment test.

1. What must stay on when NEPA takes light?

Separate essentials from appliances you can postpone. For this example, the household wants fans, lights, a television and internet during the evening. The laptop is charged during the day. The iron, kettle, cooker, water pump and air conditioner are excluded.

The figures below are editable assumptions, not typical ratings for every Nigerian appliance. Replace them with measurements or the equipment label. A charger’s maximum rating can overstate its average use.

Multiply quantity × watts × hours for each row, then add the energy column. Here the result is approximately 1.50kWh of appliance energy daily. The 293W figure answers a different question: demand if every listed appliance runs simultaneously.

This distinction follows the energy-accounting approach in Victron’s solar sizing explainer. Its setting is an RV; the worksheet above is our own household example, not a Nigerian system recommendation from Victron.

What about a fridge, freezer or AC?

Add these separately. Request their measured daily energy use and starting requirements. A fridge’s compressor does not necessarily run continuously, so multiplying one running-watt figure by 24 hours can misrepresent its consumption. Keep a note of operating conditions alongside a measurement.

For an initial comparison, choose appliances in our runtime calculator. It assumes its selected appliances run together; it does not model this table’s different daily schedules or compressor cycling.

2. Size the battery for the period without charging

Suppose all the example’s daily energy must come from the battery before it recharges. Use these explicit planning assumptions:

• Appliance energy: 1,496Wh.
• Conversion efficiency: 90%.
• Extra battery-side inverter idle draw: 10W for 12 hours, or 120Wh.
• Usable share of nominal battery energy: 90% for the illustrative lithium case.

Required nominal storage = (1,496 ÷ 0.90 + 120) ÷ 0.90 = about 1,980Wh, or 1.98kWh.

This is a calculation threshold under the stated assumptions, not a recommendation to buy the nearest 2kWh battery. It leaves little margin for unexpected use, ageing or another outage before recharge. If your efficiency estimate already includes idle consumption, do not add that loss twice.

Keeping every other assumption unchanged but allowing only 50% usable capacity gives about 3.56kWh nominal storage. That sensitivity example explains why equal advertised Wh does not always mean equal planned backup hours. Actual allowed discharge must come from the battery manufacturer.

Only need evening backup while the laptop runs directly from daytime generation? Recalculate for the evening portion. Need two days without replenishment? Recalculate both load energy and idle time for that longer interval.

Compare lithium battery listings or read what 200Ah means for runtime. Always specify bank voltage alongside Ah.

Choose inverter output separately from battery hours

Our worksheet’s 293W simultaneous load does not select a complete inverter model. The installer still needs to check continuous output, appliance startup, battery discharge limits, operating temperature and any planned additions. A larger inverter does not create additional battery energy.

Victron’s inverter selection guide distinguishes continuous and peak performance and calls for final system sizing to be confirmed with an installer. Our 3kVA load guide explains why the model’s actual watt rating matters.

3. Plan panels around daily replacement and recharge

Tell the installer whether solar must carry daytime appliances, restore last night’s battery use, or also recover after several cloudy days. Ask for expected generation for your location and the less favourable months—not just the panel nameplate total.

For a simple sensitivity exercise, suppose the design needs 2kWh per day delivered after its assumed losses. This is an illustrative target, not a measured local yield or a completed design for the worksheet above.

These are hypothetical scenarios, not forecasts for Lagos, Abuja or any other city. They show why the same daily demand can require different array sizes when the yield assumption changes. Do not apply another loss factor if your chosen yield already accounts for those same losses.

The Global Solar Atlas is a starting point for location-based solar-resource research. A site assessment must also examine shade, roof space and the intended mounting arrangement. Your installer should document their generation assumptions and the backup plan for poor-weather periods.

Panel count alone also cannot confirm compatibility. Ask the installer to match the proposed array with the controller or hybrid inverter’s voltage and current limits. See our panel price guide for component costs; panel-only prices exclude the rest of the installation.

4. Ask for an itemised Nigerian installation quote

Send the same appliance worksheet and backup target to each installer. A package described only as “3kVA solar” is too incomplete to compare fairly.

Use our inverter price guide to inspect component offers, not as a substitute for a full installed quote. We have not obtained a site-specific installed price for this example, so there is no claimed all-in naira total here.

Questions before you commit

Can I choose solar by the number of bedrooms?

No single size follows from “two-bedroom flat.” Two households in the same flat can have very different appliance lists, schedules and backup expectations. Use the worksheet instead.

Should a tenant buy a portable power station?

Include it in the comparison if you need a movable option for a few devices. Check charging access, sockets, output and stored energy. For fixed panels or building changes, establish landlord permission and installation scope first. See inverter versus power station.

Will a bigger battery solve slow charging?

A bigger battery provides more storage but does not increase the energy arriving from the panels. Include a recharge target in the design, especially if you expect repeated outages.

Method: original worked arithmetic with stated assumptions; no product testing or site survey claimed. Sources checked 24 September 2026. How we research guides · Send a correction.