How to read your City Power bill
Tony Lopes
Short answer: Look for four things: the kWh you used, the energy charge per kWh (which rises in blocks as you use more), the fixed monthly charges, and any solar (SSEG) items. Divide the month's kWh by the days in the billing period to get your average daily use. That figure is the starting point for sizing solar.
Last updated November 2026.
Your electricity bill or prepaid history holds most of what an installer needs to size a system, and it shows where a tariff re-optimisation could save money. This guide walks through a City Power account in Johannesburg. Layouts vary between postpaid accounts, prepaid statements and the municipal (City of Johannesburg) rates account, but the same items appear.
How do I read my City Power electricity bill?
| Item | What it means | Why it matters for solar |
|---|---|---|
| Consumption (kWh) | Units used in the period, from the meter readings or your prepaid purchases. | The main sizing input. Check whether readings are actual or estimated. |
| Energy charge (R per kWh) | Price per unit. Residential tariffs use blocks, so each kWh above a threshold costs more. | Solar cuts your most expensive top-block units first. |
| Fixed charges | Monthly service or network charges you pay regardless of use. | Solar doesn't reduce these. Leave them out of savings sums. |
| Billing period | The dates the reading covers, often not a calendar month. | Use the actual number of days to work out daily use. |
| SSEG or export items | Lines relating to a registered solar system, such as export credits. | Only appear once the system is registered and on a suitable meter. |
| VAT | 15% on top of the charges. | Use VAT-inclusive rates when working out savings. |
Current City Power rates and block thresholds are in our guide to City Power tariffs for 2026/27. Tariffs change every 1 July.
How do I find my monthly kWh?
- Postpaid: take the consumption figure on each bill, or subtract the previous meter reading from the current one.
- Prepaid: add up the kWh on your token slips or in your vendor app for each month.
- Collect 12 months if you can. Winter use is usually higher, and a system sized only on summer bills will fall short.
- Work out daily use: monthly kWh divided by the days in the period. For example, 900 kWh over 30 days is 30 kWh a day.
Then follow what size solar system you need.
Why did my bill go up after registering solar?
Registering a system can move a prepaid customer onto a postpaid tariff with higher fixed charges, and the fixed charges stay the same however much solar you produce. Your energy purchases should still fall. If the bill looks wrong, compare the kWh and fixed charges before and after. See SSEG registration in Johannesburg.
Frequently Asked Questions
What is the network capacity charge?
A fixed monthly charge for being connected to the network, separate from what you use. Solar doesn't reduce it.
How do I find my monthly kWh?
From the consumption line on a postpaid bill, or by adding up prepaid token kWh for the month.
Why did my bill go up after registering solar?
Usually because of a move to a tariff with higher fixed charges. Check the kWh you bought, which should have fallen.
Where We Fit In
Send us a year of bills and CleanVolts matches you with a registered CleanVolts Approved installer who sizes the system from your real use. The installer contracts with you directly. Using CleanVolts costs you nothing, and if the installer pays us a referral fee, we tell you up front.
Sources: City Power tariff schedules approved by NERSA for 2026/27.
