solar calculator

Calculate your solar panel size, battery capacity and inverter needs in minutes. This South African solar calculator shows exactly how many panels you need, how much battery backup to install and the total power your system must deliver. Use it for homes, shops or small businesses. Enter your usage and get instant results.

ELECTRICITY SPEND TO KWH ESTIMATOR (OPTIONAL)

Don't know your daily kWh? Enter your monthly Rand spend and we'll estimate it. The result will fill the "Units per day" field below.

Province

Town / City

Tariff Type

Average Monthly Energy Spend (R)

Estimated Monthly Usage

Estimated Daily Usage

Average Cost Per kWh

INSTALLATION ADDRESS

Select your location to estimate Peak Sun Hours (PSH).

Province

City / Area

SOLAR PANEL SIZING (24H BASE)

Units per day (kWh/day)

Solar Panel Size (W)

Typical residential panels: 450W, 550W, 565W, 600W.

Peak Sun Hours Per Day (PSH)

System Losses %

Array orientation (azimuth)

Panel orientation: -, Sun capture: - Select Direction

NESW

Tip: North works best in South Africa. East and West still work.

Your Tilt / Roof Angle (degrees)

0 degrees = flat, 90 degrees = vertical. Typical: tile 20 to 25, IBR 10 to 15.

Recommended Fixed Tilt degrees (year-round)

Roof tilt: - degrees, Difference: - degrees, Sun capture: - Insert Tilt

Green line shows best angle. Dark panel shows your angle.

Daily usage

Required panels

Array size

BATTERY SIZING FOR NIGHT USE

Based on use from 17:00 to 08:00, 15 hours total.

Night-time usage 17:00 to 08:00 (kWh)

Battery module size (kWh)

Capacity per battery module.

Depth of Discharge (% DoD)

Days autonomy

Night avg. power

Required battery

Battery modules

Frequently Asked Questions

How many panels does a 5kW inverter need?

Most 5kW inverters pair with 9 to 10 panels of 550W. Ask how many solar panels do I need for your load first, then compare our 5kW solar packages.

How many panels charge a 5kWh battery?

Plan for 3 to 4 extra panels of 550W to refill a 5kWh battery by mid afternoon. Sun hours differ by site, so check the Global Solar Atlas map.

Does the inverter limit my panel count?

Every inverter caps its PV input in watts and voltage. Sizing how many solar panels for 8kW inverter models starts with that datasheet limit.

How many panels run a geyser and fridge?

A 5kW system with 9 to 10 panels runs a geyser and fridge. Our solar panel calculator also answers how many solar panels to run a refrigerator and freezer.

How many panels does a borehole pump need?

Pump power sets the count, and a 2.2kW pump usually needs 5 to 6 panels of 550W. Farms and smallholdings often add 1 or 2 panels for cloudy mornings.

Can I add more panels later?

Yes, provided the total stays within the inverter's PV input limit. Before adding a string, ask how many solar panels can my roof hold.

What panel wattage suits a small roof?

Higher wattage panels, such as the Longi 590W, fit more power per m². Roof size and shading still shape how many solar panels do I need.

How many panels come on one pallet?

One pallet of Longi 590W solar panels holds 36 panels. Installers check how many solar panels in a pallet before ordering for larger home or farm arrays.

Is 3kW enough for a small house?

Yes, for lights, a fridge, Wi-Fi and a TV, using 5 to 6 panels of 550W. Geyser homes should check how many solar panels for a 5kW system instead.

Why do panels produce less power in winter?

Shorter days and a lower sun angle cut output, so size arrays for winter. Solar Panel Energy answers what size solar system do I need with a free load calculation.