How Many Solar Panels and Batteries Do You Need? A Nigerian Sizing Guide

“How many solar panels and batteries do I need?” is the first question every client asks. The answer comes from three numbers: how much energy the home uses each day, how many hours of strong sun the site gets, and how long the batteries must last. Here is the method, step by step, using a home in Uyo, Akwa Ibom as the example.

Step 1: Work out daily energy use

For each appliance, multiply running watts by quantity and by the hours it runs each day. That gives watt-hours (Wh). Add them up.

The fridge is counted at 10 hours, not 24, because its compressor switches on and off.

Step 2: Allow for losses

Energy is lost in the charge controller, the battery and the inverter. With about 90% efficiency at each stage, divide by 0.9 three times:

6,488 ÷ 0.9 ÷ 0.9 ÷ 0.9 = 8,900 Wh a day that the system must produce.

Step 3: Size the solar panels

Divide the daily energy by the site’s peak sun hours. Peak sun hours are not daylight hours. They are the equivalent number of hours of full-strength sun.

Nigeria gets more sun the further north you go. Southern cities such as Uyo, Port Harcourt and Lagos typically get around 4 to 4.5 peak sun hours, while the far north can get 6 or more. For Uyo, using 4.2 hours:

8,900 ÷ 4.2 = 2,119 W of panels, which is four 550 W panels (2,200 W).

In Kano, at around 5.5 hours, the same home needs about 1,618 W, which is three panels. Allow extra for cloudy rainy-season days in the south, and for heat and dust, which reduce panel output.

Step 4: Size the battery bank

First decide how many days of storage the client needs without sun. One day is common for homes with some grid supply. Then:

1. Storage needed = 8,900 Wh × 1 day = 8,900 Wh.
2. Convert to amp-hours at the bank voltage: 8,900 ÷ 48 V = 185 Ah.
3. Allow for depth of discharge, the share of the battery you plan to use.

Lithium (LiFePO4), 80% depth of discharge, 48 V bank: 185 ÷ 0.8 = 232 Ah at 48 V, about 11 kWh. That is three 48 V 100 Ah lithium batteries in parallel.

Lead-acid or tubular, 50% depth of discharge, 24 V bank: 8,900 ÷ 24 = 371 Ah, and 371 ÷ 0.5 = 742 Ah at 24 V. With 12 V 200 Ah batteries, that is four strings of two batteries in series, or eight batteries in total.

Lead-acid costs less to buy but needs about three times the capacity and lasts fewer cycles. Lithium costs more upfront and usually less over its life. Always check the depth of discharge on the battery’s datasheet.

Step 5: Size the charge controller

Divide the panel watts by the battery bank voltage: 2,119 W ÷ 48 V = about 44 A. A 50 A or 60 A MPPT charge controller suits this home. Many hybrid inverters have one built in, so check its maximum solar input.

Summary for this Uyo home

• Daily energy: 6,488 Wh, or 8,900 Wh with losses
• Solar panels: four 550 W panels (2.2 kW)
• Batteries: about 11 kWh of 48 V lithium, or eight 12 V 200 Ah lead-acid batteries on a 24 V bank
• Charge controller: 50 to 60 A MPPT
• Inverter: 1.5 kVA. See our inverter sizing guide

Let the software do the sums

Soliqo calculates all of this live as you build a load list. It covers losses, sun hours, battery type, bank voltage and days of storage, and shows how many panels and batteries to quote. Change a value and every result updates. See the plans or start a free trial.