The AC Plug Fiasco - Spelt Out
Q) Should Scottish and Dundee Councils be giving electric car drivers the option of a cheaper charging cost with AC plug use?
AC users should logically have a cheaper tariff, because AC is slower, gentler on the grid, and far cheaper to maintain than DC.
But Dundee’s system isn’t built around fairness by connector type — it’s built around recovering the cost of rapid‑charger infrastructure
That’s why AC gets lumped into the same 69p/kWh bracket.
Let me break down why this happens, and what needs to change for AC pricing to drop.
⚡ Why AC should be cheaper (from a technical and economic standpoint)
AC hardware is cheap — a 22 kW AC post costs a fraction of a 50–150 kW DC unit.
AC has no active cooling, no high‑power rectifiers, and far fewer failure points.
Grid demand is lower, so standing charges are lower.
Wear and tear is minimal compared to DC.
From a cost‑reflective perspective, AC should be 30–45p/kWh, not 69p.
This is why many councils in Scotland price AC lower — but Dundee City Council doesn’t.
🟦 Why Dundee Council doesn’t offer cheaper AC pricing
1. You’re using AC on a rapid charger cabinet
Even though you’re on the AC plug, the whole unit is a rapid charger, and the Council prices the unit, not the connector.
2. Dundee uses a “flat tariff” model
Their policy is deliberately simple:
One price
All connectors
All rapid chargers
This avoids complexity but punishes AC users.
3. The network must be financially self‑sustaining
Dundee has one of the densest EV networks in the UK. To keep it running without subsidies, they:
Raised prices in 2025
Removed connection fees
Standardised tariffs
Cheaper AC would reduce revenue.
🟢 Could AC pricing drop in the future?
It could, but only if one of these happens:
Council introduces time‑of‑day pricing
Urban Fox undercuts Evolt further
Solar + battery hubs reduce operating costs
Scottish Government reintroduces charging subsidies
A tariff review explicitly separates AC from DC
Right now, none of these are in motion.
🧭 The real issue: AC users are subsidising DC users
You’re paying rapid‑charger prices for slow charging, which is fundamentally unfair.
If Dundee priced AC fairly (say 40–45p/kWh), your yearly cost would drop by £400–£600 based on a 20 kWh × 2 per week pattern.
Q2) If I charge at a rate of 22kw with AC and the Zoe I have sustains a constant 29kw with DC why am I paying the greater charging tariff?
You’re making a really sharp point here—and you’re right on two levels:
For you as a driver: 22 kW AC vs ~29 kW DC on your Zoe is not a big real‑world difference.
For fairness: paying the same 69p/kWh for both feels wrong when the experience is so similar.
Let’s put some numbers on it, then look at why the price is still the same.
1. What 22 kW AC vs 29 kW DC actually means for you
You said you take about 20 kWh per session.
On 22 kW AC:
Time=2022≈0.91 hours≈55 minutes
On 29 kW DC:
Time=2029≈0.69 hours≈41 minutes
So you’re paying the same 69p/kWh for:
~55 minutes on AC
~41 minutes on DC
That’s only about a 14‑minute difference per session. From a user’s point of view, that absolutely does not justify “premium rapid” pricing on AC.
2. Why the operator still treats them as “the same”
The frustrating bit: the tariff isn’t based on your power level, it’s based on the charger type and site economics.
Same cabinet: your 22 kW AC is likely coming from the same rapid charger cabinet that also does DC. The council prices the whole unit, not each connector.
High fixed costs: grid connection, standing charges, civil works, maintenance, back‑office, payment systems—those are mostly the same whether you pull 22 kW or 29 kW.
Policy simplicity: Dundee has chosen a flat rapid tariff: one price, all plugs. It’s administratively easy, but it’s blunt and unfair at the edges—like your case.
So from their side: “this is a rapid site, so it’s 69p/kWh”. From your side: “I’m basically on a fast AC post, why am I paying rapid DC money?”
3. Why your argument is actually strong
You’ve got a very reasonable case to make:
Your Zoe’s DC is modest: it’s not like you’re jumping from 22 kW to 100+ kW.
Your session size is small (20 kWh): the time saved on DC is marginal.
You’re choosing AC for battery health, not to hog a rapid bay.
You’re effectively cross‑subsidising high‑power DC users while getting almost no benefit from the “rapid” label.
That’s exactly the kind of nuance councils don’t see unless drivers spell it out.
