Your bill will not drop to zero with embedded generation because most of what you pay a municipality is not payment for electricity. A municipal account is a stack of charges — a fixed network charge, a meter or reading fee, often a service or availability charge, and VAT on the whole lot — and only the energy line responds to what your panels produce. Feed-in credits, where a municipality offers them at all, are applied to that energy line and almost nothing else, which is why a house that imports next to nothing in a sunny month can still owe a floor amount before it has bought a single unit.
I keep my municipal bill in the same flip file as the COC and the inverter datasheet, and every few months I take it out and lay it flat on the kitchen counter. Not to admire the drop. To find the floor.
The number at the bottom is a sum, not a price
Do this with me. Take your last account, put a ruler under the electricity block, and draw a line down the middle of the page. Left column: lines that move with units. Right column: lines that don't.
On the left you'll usually have the energy charge — the actual cents-per-kWh part, sometimes split into blocks or seasons. On the right you'll have the network charge, the meter or reading fee, and whatever service charge your council attaches to the connection. VAT sits underneath, applying to both columns.
That right-hand column is the thing nobody tells you about at the quote stage. It is also, for most houses I've looked at, the reason the bill refuses to die.
What the fixed charge is actually paying for
A municipal network charge is not a penalty for using less. It's your share of a grid that has to exist whether you import from it or not — the transformer on the corner, the cable down the street, the fault team that comes out at eleven at night, the substation that has to hold voltage for everyone on the feeder. When you register embedded generation, you don't stop being connected to that.
I've heard the argument that a solar household should pay nothing because it isn't using the network. It doesn't survive contact with the bill. The connection stays. The charge stays.
The meter is a line item too
If you want to export, a standard prepaid or credit meter won't do it. You need a meter that measures both directions, and that meter arrives with an installation cost, sometimes a deposit, and usually its own recurring reading or network-access fee on the account afterwards. Even if you go zero-export and never push a unit back, the SSEG registration process pulls you onto a tariff structure that may carry a different fixed arrangement than the plain domestic one you were on.
I've watched people budget for panels, battery and inverter down to the last rand and then get ambushed by the meter and the registration, because those costs don't live in the solar quote. They live in the municipal account, one or two billing cycles later.
The credit side, and why it's worth less than you think
The feed-in credit is not a mirror of the retail rate. It is set separately, it is usually well below what you pay for a unit you import, and it is applied to the energy portion only. It does not wipe the network charge. It does not wipe the meter fee. It generally does not wipe the VAT sitting on those fixed lines either.
Here's the part that gets missed, and it's the part I'd want someone to tell me early.
If your municipality bills residential energy in blocks, the units you avoid by going solar are the expensive ones at the top of the stack. That feels like a win, and it is. But the units you earn a credit for are priced below even the cheap first block. So the credit is worth less than the unit it replaces — not by a small margin, but twice over: once because it's a lower rate, and again because you were never going to pay the top-block rate for the unit you avoided. Anyone modelling savings as "exported units times my retail rate" is building on sand.
Credit is not always cash
Some municipalities carry the credit forward on your account rather than paying it out. You accrue a balance that offsets future energy charges, and if you sell the house, the balance doesn't walk into your bank account. Others don't offer a feed-in credit at all and permit self-consumption only, with the meter configured to block export entirely. In that case the export column of your savings model is simply zero, and the fixed charges still stand.
And the structures aren't uniform across customer classes. What a household on a residential embedded generation tariff sees is not what a small commercial or an agricultural connection sees, even inside the same municipality. The fixed component is often shaped around the size of the connection.
Who actually decides the shape of this
NERSA approves municipal tariffs, but the structure — which charges exist, what sits in the fixed block, whether there's an export credit at all — is proposed by the municipality and goes through its own council process. That's why two towns an hour apart can treat an identical rooftop completely differently. It also means the structure can be revised. The architecture of your bill is not a fixed law of nature; it's an approved schedule that gets revisited.
Which is exactly why I don't chase the current numbers. I chase the shape. If I know which lines are fixed and which are unit-driven, a tariff revision changes the arithmetic but not my reasoning.
The calculation I actually run
Once a year, I add up every line on the right-hand column — network charge, meter fee, service charge — plus the VAT that attaches to them. That total is my floor. It is what I will owe in a month where the sun is generous and the battery holds.
Then I take the solar proposal and compare its claimed monthly saving against the gap between my old bill and that floor — not against the old bill in full. If a proposal shows a saving that would push the account below the floor I calculated, one of two things is true: I've misread the bill, or the proposal has.
That single subtraction has saved me more arguments than any monitoring app.
The things I still get wrong
I don't know your municipality's current schedule, and I'm not going to guess it. Block boundaries shift, fixed charges get restructured, and the export rules in one council area can be rewritten by the time you read this. What doesn't shift is the logic: find the lines that don't move, add them up, and treat that number as the real baseline your system is working against.
And there's a genuine tradeoff in the tariff switch itself. Moving onto an embedded generation tariff can lower the per-unit energy rate while raising the fixed component. That can be a good deal for a heavy importer and a poor one for a light importer. It depends on your load profile, and no quote will tell you which side of that line you're on.
The bill was never going to zero. But once you can see the floor, the system starts making sense in the right frame — not as a machine that deletes the account, but as one that pays down the part of the account that was ever yours to move.
