Shell Hong Kong · EV charging · For discussion

Shell Recharge is Hong Kong’s largest fast-charging network.
This is about what it costs to run.

Built entirely from public information — Shell’s own site locator and Recharge pages, the EPD charger register, 中電 CLP and 港燈 HK Electric published tariffs, and a listed competitor’s audited accounts. Sourced figures carry their source; modelled figures are labelled as estimates. Nothing is drawn from inside Shell.

Start here

One number you can check against a single bill

The whole finding

Below roughly 7.5% utilisation, the demand charge alone eats the entire margin on a kWh.

Not a saving I am claiming. A threshold you can test. Twenty-one of your largest charging sites sit in 中電 CLP territory, and 中電 CLP’s Bulk tariff bills on the on-peak maximum demand recorded in the month, plus any off-peak excess, subject to a 100 kVA minimum — a fixed cost, recovered over however many units happen to be sold.

The arithmetic, in full

Demand cost per kWh = rate ÷ (730 hours × load factor)

Load factor here means units sold divided by (billed maximum demand × 730 hours). Not against the equipment installed — against the peak kVA that actually appears on the bill. Those are different numbers, and only the second one is charged for.

That is the entire model. Put in your own demand rate and your own load factor and it answers itself in about sixty seconds. Nothing in it requires anything I could not read off a published tariff table.

Read one row at a time. On my assumptions the spread on a unit is about HK$1.36 — Shell’s published price less electricity at the EV tariff and an assumed site cost. Your real figure will differ. The question is simply whether the demand charge on that site costs more or less than that.

How busy the site is Demand charge
costs, per unit sold
Shell earns
per unit sold
Left over
Nearly empty — 2% HK$5.13HK$1.36 −HK$3.77
5.5% — my estimate for the network HK$1.87HK$1.36 −HK$0.51
Quiet — 6% HK$1.71HK$1.36 −HK$0.35
The turning point — 7.5% HK$1.36HK$1.36 HK$0.00
Busy — 15% HK$0.68HK$1.36 +HK$0.68
Very busy — 40% HK$0.26HK$1.36 +HK$1.11

On CLP’s Bulk tariff at HK$74.90 per kVA a month. Above the turning point the demand charge is covered by the spread; below it, it is not — before any other cost is counted. That is a statement about one line on the bill, not about whether a site is profitable overall. Hong Kong Island sites buy from 港燈 HK Electric at HK$48.30 per kVA (low voltage; HK$47.30 high voltage), where the turning point is 4.9% — but only 2 of the 23 large sites are there.

Two thresholds, two different decisions

The 7.5% above answers “which tariff should a site I already own be on?” The equipment is already bought, so its cost is sunk and does not belong in that comparison.

A different question — “should we build another bay?” — has to carry the capital too. At HK$317,520 a bay over eight years at 8.3%, plus O&M, that adds the equivalent of about HK$46 per kVA a month on top of the tariff, and the threshold moves to roughly 10.4%.

Both are right. I am only claiming the first. The second is why I would not lead with building more chargers.

Why the cost side, not the price

On a quiet site this one line is bigger than the entire margin

At 5.5% the demand charge costs HK$1.87 a unit against HK$1.36 of margin. It is close, and that is the point — the estate sits right on the line, so which side a given site falls is a question of fact, not opinion. No pricing change reaches a number that size, and raising the price is the one move 中石化 Sinopec has already made impossible at HK$1.68.

What kills it

If those sites are already on the EV tariff

The EV tariff has no demand charge at all. If that is where the estate sits, this idea is worth nothing and I would rather find out over lunch than in week two.

The 5.5% load factor is an outsider’s estimate, not an observation: a public revenue anchor spread evenly across the estate, then set against an assumed 70% coincidence between installed power and billed peak. Real sites will sit either side of it, and the busy ones well above. The 7.5% threshold does not depend on it at all — that comes only from the published tariff and the spread. Everything else here comes from Shell’s own published locator, the EPD charger register and the two utilities’ published tariffs.