Electrical equipment, whether yours or Hydro-Québec’s, needs to operate at a relatively stable voltage. Hydro-Québec’s rate structure for medium-power customers is designed in such a way as to encourage customers to maintain a power factor (PF) of at least 90% at all times.
When customers make less than optimal use of the electricity provided to them, resulting in a PF below 90%, Hydro-Québec has to supply them with additional power and handle the impacts on the power system.
To ensure that such customers pay the real cost of their electricity supply and thus ensure fair treatment for all customers, the company applies a charge for each kilowatt of apparent power exceeding the limits set in the rate.
A monthly charge of $10.23 per kilowatt applies to any difference between maximum power demand and real power.