Your September bill landed. It’s smaller than August. Nothing in your business changed.
Same shifts. Same machines. Same orders.
The bill still came down.
Eskom’s price schedule lists fourteen separate charges on a Megaflex bill. Only two of
them changed on 1 September. Once you know which two, the rest of the page makes sense.
It isn’t a credit. It isn’t a meter fault. It isn’t the April increase unwinding either —
that only moves one way.
What changed is the season.
Why is my Eskom business bill smaller in September?
Eskom splits the year in two. The high-demand season runs from 1 June to 31 August. The
low-demand season runs from 1 September to 31 May.
Two charges are seasonal. Everything else on the page is the same in January as in July.
The first is the energy rate in the peak periods. In winter you pay 720.19 c/kWh. In summer
you pay 298.89 c/kWh. That’s a drop of 421.30 cents for the same unit of electricity.
720.19 c/kWh in winter. 298.89 c/kWh in summer.
Same meter. Same machine. Same kilowatt-hour. Megaflex peak-period
energy, excluding VAT.
The standard-period rate moves too, but only a little. It goes from 180.05 c/kWh to
168.05 c/kWh.
Off-peak doesn’t move at all. It’s 120.03 c/kWh all year.
The second seasonal charge is the reactive energy charge. In winter it’s 34.49 c/kVArh. In
summer it’s nothing. We’ll come back to that one, because it’s the strangest line on the bill.
The four kinds of charge on your bill
Every line on the page belongs to one of four groups.
Energy charges are in cents per kWh. They pay for the electricity you used.
Capacity and demand charges are in rands per kVA per month. A kVA is a
measure of how hard you pulled, not how much you used.
Fixed charges are in rands per day. You pay them for being connected.
The reactive energy charge is its own thing. It’s closer to a penalty than
a price.
Think of water. Energy is how many litres you drew. Demand is how wide the pipe had to be
for your worst moment. You pay for both, separately.
Most owners only know about the litres.
The energy charges: five lines, not one
You probably think you pay one rate per unit. You don’t. Five separate cent-per-kWh charges
stack on top of each other.
- Active energy — the rate that changes by season and time of day
- Legacy charge — 24.14 c/kWh
- Ancillary service charge — 0.42 c/kWh
- Electrification and rural network subsidy — 5.37 c/kWh
- Affordability subsidy — 5.10 c/kWh
The last four don’t change by season or by hour. They apply to every unit you draw.
So take a standard-period unit in summer. The real cost is the stack, not the headline rate:
168.05 + 24.14 + 0.42 + 5.37 + 5.10 = 203.08 c/kWh
You thought you paid 168 cents. You pay a bit over 203.
A peak-period unit in summer works out the same way:
298.89 + 24.14 + 0.42 + 5.37 + 5.10 = 333.92 c/kWh
All of these are excluding VAT. Add it and the summer peak unit lands at 343.72 c/kWh on the
active energy line alone.
Every one of these five falls if you use less, or shift load to off-peak.
That’s the good news. The next group is where it gets harder.
The capacity charges, and the trap inside them
Four charges on your bill are quoted in rands per kVA per month.
- Distribution network capacity charge — R39.13
- Distribution network demand charge — R26.29
- Transmission network charge — R11.15
- Generation capacity charge — R12.27
39.13 + 26.29 + 11.15 + 12.27 = R88.84 per kVA, per month
They look like one charge split four ways. They are not.
Three of them are billed on your annual utilised capacity. That’s the higher of your
notified limit or your worst measured demand, over a rolling twelve months.
One of them is billed on your chargeable demand. That’s your highest half-hour
average this month, in the peak and standard periods only.
Guess which one is which.
The only charge that responds to what you did this month is the distribution network
demand charge, at R26.29 per kVA.
88.84 − 26.29 = R62.55 set by a number up to a year old
This is the part that catches people. You install something, you cut a peak, and most of your
capacity bill doesn’t move. It can’t. It’s following a twelve-month high-water mark.
That high-water mark has its own fix, and it isn’t equipment. It’s paperwork. We wrote about
it in how to reduce your notified maximum
demand.
There’s a fifteenth line that only appears if you push past your notified limit. Eskom calls
it an excess network capacity charge. If you’ve seen it, your limit is set too low for how you
actually run.
The fixed charges you can’t do anything about
Two charges are billed per day, per connection point.
215.91 + 21.07 = R236.98 per day
R236.98 × 30 days = R7,109.40 a month
That’s the service charge plus the administration charge, at the largest supply size,
excluding VAT. The 30 days is just for illustration — your billing month varies.
No battery reduces this. No solar array reduces it. No tariff negotiation reduces it. It’s
the cost of having a meter.
Worth knowing anyway. It’s the floor under every saving anyone quotes you.
The line that vanished on 1 September
The reactive energy charge is the oddest item on the page.
Your motors draw two things. Real power, which does the work. And reactive power, which just
sloshes back and forth building magnetic fields.
Eskom meters both. If your reactive energy goes above 30% of your kWh in the peak and standard
periods, you pay for the excess. That threshold is a power factor of 0.96 or worse.
The rate is 34.49 c/kVArh. And it applies in the high-demand season only.
So it was on your August bill. It is not on your September bill. It comes back on 1 June.
You have eight months to fix it before it costs you anything again. The fix is
usually capacitors, and it’s cheap next to anything else on this page. There’s more detail in our
post on the reactive energy charge and power
factor.
So which lines can you actually move?
Here’s the whole bill, sorted by whether you have a lever.
- The five energy charges. Yes. Use less, or move load out of the peak blocks.
- Distribution network demand charge. Yes. This is the one peak shaving cuts.
- Network capacity, transmission, generation capacity. Not this month. These
follow your twelve-month capacity number. The lever is your notified limit. - Service and administration. No.
- Reactive energy. Yes, and cheaply. Winter only.
That ordering matters more than it looks. It tells you what to check before you spend anything.
Who this post isn’t for
If your electricity comes from a municipality, you’re not on Megaflex. Businesses supplied by
eThekwini, Johannesburg or Cape Town are on that city’s own tariff. The structure rhymes, but the
rates and the increase dates are different. Municipal rates moved on 1 July, not 1 April.
If you’re on Businessrate, this post also isn’t for you. That tariff is for urban supplies up
to 100 kVA with no grid-tied generation. It has no rand-per-kVA demand charge at all. There is
nothing there to shave, and anyone selling you peak shaving on it is guessing.
What to do this week
All four of these are free. Do them before you take a single quote.
- Pull your last twelve bills. Find the highest demand figure in kVA anywhere in that set.
- Compare it to your notified limit. If the limit is well above your real peak, you’re paying
for capacity you never use. - Find the kVArh reading on a winter bill. If there’s a reactive energy charge on it, your power
factor needs attention. - Work out roughly how much of your energy lands in the peak blocks. That single number decides
whether load shifting is worth anything to you.
Then, and only then, look at equipment. A quote that arrives before those four answers is a
brochure, not an engineering proposal.
Common questions
Why did my Eskom bill drop in September?
The low-demand season started on 1 September. Peak-period energy fell from 720.19 to
298.89 c/kWh. The standard rate fell from 180.05 to 168.05 c/kWh. The reactive energy charge went
to zero. Your capacity and fixed charges did not change at all.
Is my business on Megaflex?
Only if Eskom bills you directly and your notified capacity is above 1 MVA. If a municipality
sends your bill, you’re on a municipal tariff instead. Check who the invoice comes from before
you compare your rates to anything published for Megaflex.
Which charge does a battery actually reduce?
Two things. It cuts the distribution network demand charge, at R26.29 per kVA per month, by
lowering your worst half-hour. And it cuts energy cost by shifting units out of the peak periods.
It does not touch your capacity charges in the month you install it.
Why didn’t my bill fall when I shaved one big peak?
Because three of your four capacity charges follow a rolling twelve-month figure. One good
month doesn’t reset it. You need a sustained lower peak, or a renegotiated notified limit, before
those three lines move.
What is a kVA, and why am I billed on it?
A kVA measures the size of the demand you placed on the network, not the energy you consumed.
Eskom has to build wires and transformers for your worst moment, not your average one. The kVA
charges pay for that capacity sitting there, ready.
Should I just switch tariffs instead?
Sometimes that’s the cheapest move available, because it costs nothing but paperwork. It
depends entirely on the shape of your load through the day. Work through the four free steps
above first — they produce exactly the data a tariff comparison needs.
Where to go next
Not sure which of these lines is driving your bill? Start with
why your business electricity bill is so
high. If you want the seasonal picture, read
Eskom winter tariffs: time-of-use versus
demand charges.
Or send us twelve months of bills and we’ll tell you which lines are actually movable at your
site. No equipment in the first conversation.
All rates from Eskom’s Schedule of Standard Prices for
tariffs effective 1 April 2026. Figures quoted are non-local-authority Megaflex rates, excluding
VAT unless stated. They apply to a Transmission zone up to 300 km and a supply of 500 V or more
and under 66 kV. Your own bill will show the band that applies to your connection. Charge
definitions and the reactive energy threshold come from the same schedule.
