The main cost involved in the entire power supply chain is the amortisation of capital. It is a fixed cost in $/kW.
The current tariff system, however, is "designed" mainly around a variable cost, in $/kWh.
Therefore, there is a "mismatch," which ends up transferring costs incoherently and even unfairly.
Here's a simple example to show "what it's about." A residence with two instant electric showers that may be operating simultaneously demands a much higher power from the grid in kW than a residence that installs a central (tank) water heater to supply both showers.
But... by the end of the day they pay the same total $ because in this example they use the same amount of energy. The proposal I present is to create a tariff centered on $/kW, to reflect reality as it is!