Your July electricity bill arrived. It’s thousands more than June.
You didn’t buy a new machine. You didn’t hire anyone. You didn’t change your hours. Nothing in your business changed.
So why is your business electricity bill so high?
The answer is on page two. Almost nobody reads page two.
The short version
- Your bill charges you two ways. Almost everyone only knows about one of them.
- The second one is called a demand charge. It’s based on your biggest moment, not your total use.
- On Eskom’s Nightsave Urban tariff, that charge is R332.91 per kVA in winter. In summer it drops to R77.88.
- That’s the same charge. It’s 4.3 times bigger from June to August.
- You can lower it. Some of the ways cost nothing.
First, let’s rule out the obvious answers
It’s not load shedding. Load shedding costs you money, but it doesn’t raise the rate on your bill.
It’s not only the annual increase either. Eskom’s direct customers went up 8.76% on 1 April. eThekwini put electricity up 9% on 1 July. Other municipalities did something similar.
Those increases are real. But a 9% rise doesn’t explain a bill that jumped by a third.
Something else is going on. And it happens every year at the same time.
Your bill charges you twice
Think about water for a second.
You pay for the litres you use. That part is obvious. But someone also had to size the pipe. A big pipe costs more to build than a small one — even if you only open the tap now and then.
Electricity works the same way.
You pay for the units you use. You also pay for the biggest gulp you took.
The first part is the energy charge, measured in cents per kWh. Most business owners know this one.
The second part is the demand charge. It’s measured in rand per kVA, per month. kVA is just a way of measuring how hard you were pulling at one moment in time.
Here’s the part that catches people out.
The demand charge doesn’t care how long you pulled that hard. Your meter looks at every half hour of the month. It finds the single worst one. Then it charges you for that, all month.
Switch on three compressors together at 07:00 on one Tuesday in July, and you’ve set the price for all thirty-one days.
And in winter, that charge explodes
This is the bit that answers your question.
Eskom runs two seasons. The high-demand season is June, July and August. Everything else is the low season.
Look at what happens to the demand charge on Nightsave Urban, a common tariff for medium-sized industrial sites:
Energy demand charge — Eskom Nightsave Urban
Winter (Jun–Aug): R332.91 per kVA, per month
Summer (Sep–May): R77.88 per kVA, per month
Same charge. Same site. 4.3 times the price. Rates exclude VAT.
Nothing about your factory changed. The calendar changed.
Add the network demand charge of R26.29 per kVA, and the number that moves with your peak is this:
R332.91 + R26.29 = R359.20 per kVA, per month, in winter.
In summer the same sum is R77.88 + R26.29 = R104.17.
What that looks like in rand
Say your site peaks at 400 kVA. Here’s the demand portion of your bill:
- Winter: 400 × R359.20 = R143,680 a month
- Summer: 400 × R104.17 = R41,668 a month
That’s a difference of over R100,000 a month. For three months of the year. Every year.
You can check this yourself tonight. Find the kVA figure on your bill. Multiply it by the rate next to it. The sum will match.
If you’re on a time-of-use tariff, there’s a second trap
Some businesses are on Megaflex. On that tariff the energy charge also changes — by the hour.
In winter, a unit of electricity costs 720.19c during the peak hours. The same unit costs 120.03c overnight.
That’s six times the price for the identical kilowatt-hour.
The peak hours are short. There’s a block in the early morning and another in the early evening, about two hours each, on weekdays only. Your exact times are in Appendix A of Eskom’s published tariff schedule.
If your heavy work happens to land inside those blocks, you’re paying the highest rate Eskom charges anyone.
What you can do about it
Start with the things that cost nothing.
1. Find your peak. Ask your supplier for your half-hourly demand data. Most will send it. Look for the spike. It’s usually one predictable moment — a shift start, a compressor bank, an oven and a chiller waking up together.
2. Stagger your start-ups. If three big loads switch on at once, delay two of them by ten minutes. This is free. On some sites it’s worth tens of thousands a month.
3. Move what you can out of the peak blocks. Charging, pumping, milling, pre-cooling. Anything that doesn’t have to happen at 07:00 shouldn’t happen at 07:00.
4. Then look at equipment. A battery can hold your peak down automatically. Solar can cut the units you buy during the day. Which one helps more depends entirely on your tariff — and that’s a real question, not a sales question. Our guide to demand charges versus energy arbitrage walks through how to tell them apart.
When this doesn’t apply to you
Not every business has a demand charge.
If your connection is 100 kVA or smaller, you’re probably on a tariff like Businessrate. Those tariffs have no rand-per-kVA charge at all. You’re billed on units and a daily fee.
In that case, none of the above will save you a cent. Your lever is total consumption, not peak timing.
Check page two before you spend money on a fix for a problem you don’t have.
Why next winter will be worse
There’s one more thing you should know.
NERSA made a R54.7 billion error working out what Eskom is owed. A court told them to consult the public. They decided to recover the money over three years.
This year’s share is R12 billion. Next year’s share is R23 billion.
Without that recovery, this year’s increases would have been 5.36% and 6.19%. Instead they were 8.76% and 9.01%.
The instalment nearly doubles next year.
So if you’re working out whether a fix pays for itself, today’s tariff is the cautious number. Not the optimistic one.
Frequently asked questions
Why is my electricity bill so high in winter but not in summer?
Because Eskom charges a higher demand charge in June, July and August. On Nightsave Urban it goes from R77.88 to R332.91 per kVA. Your usage may be identical. The season is what changed.
What is a kVA charge on my business electricity bill?
It’s a fee based on the highest amount of power your site pulled in any half-hour of the month. It has nothing to do with how many units you used in total. One brief spike sets the charge for the whole month.
Can I lower my demand charge without buying anything?
Often yes. Staggering equipment start-ups and moving flexible work out of the morning and evening peaks costs nothing. Many sites find their peak is one avoidable moment. Start there before you look at batteries.
Will solar panels reduce my demand charge?
Only partly, and not reliably. Solar cuts the units you buy while the sun is up. But your peak often happens early in the morning or after dark. Solar can’t help then. Storage or load control can.
Am I on the right tariff?
Many businesses aren’t. Tariffs are chosen once and rarely reviewed. If your load shape has changed since you signed up, a different tariff may fit better. Ask your supplier what alternatives you qualify for.
How do I find these charges on my bill?
Look for a line measured in kVA rather than kWh. It’s usually on the second page, under network or demand charges. If you can’t find it, send us the bill and we’ll point at it.
The next step
You don’t need to buy anything to start. You need to know where your peak is.
Send us twelve months of bills and we’ll show you what’s driving the number. Which charge is hurting. When it happens. What it would take to move it.
If the answer is that you should change one start-up time and nothing else, we’ll tell you that.
Find out what’s really on page two
Send us your last twelve bills. We’ll read them properly and tell you where your money is going. No obligation, and no pitch until the numbers say there’s something worth doing.
Tariff rates quoted are from Eskom’s Schedule of Standard Prices effective 1 April 2026, for non-local-authority supply at 500V–66kV, and exclude VAT. Municipal customers are billed on their own municipality’s tariff — check your schedule, as your rates and seasons will differ. Related reading: how winter tariffs actually work and our savings calculator.
