Simple charging arithmetic.
Say battery capacity = 60 kWh
To charge up battery, need input charging power of 60 kW for 1 hour.
To charge up in 30 minutes, you need input charging power 120 kW.
To charge up in 10 minutes, you need input charging power 360 kW.
Say HDB car park has 4 charging lots.
Need total 4x360 = 1.44 MW for 10-minute charging.
But if restrict to minimum 1-hour charging, need 4x60 = 240 kW only.
Assume 100 HDB car parks with 400 charging lots total
Assume all charging lots only used once daily. Max 400 EVs are charged per day. No one queues up wait for charger.
Total need 144 MW power per day from Power Grid for 10-minute charging, or 24 MW power draw per day from Power Grid for 1-hour charging.
It's all about money. Laying new 1.44 MW power cables from substation way more ex than laying new 240 kW power cables. How much does it cost to build 4 charging lots with 1.44 MW power line from substation? With 240 kW power line? I don't know. Does anyone know what is the cost? You know we taxpayers are paying for all these whether we have EVs or not, right? EV owners must pay more road tax to cover these costs.
Can existing Power Grid support additional 144 MW power draw per day? Most likely will be limited to 1-hour charging at the minimum coz only need additional 24 MW power draw per day. Or maybe SG will go all nuclear? No more fossil fuel power generation in future, all power stations will be nuclear?
