A deep discount on the overnight power rate could be on offer in Ontario as early as this spring. Under the program’s recently finalized rules, local distribution companies (LDCs) throughout the province must have the new optional time-of-use electricity rate scheme ready for residential and small business customers no later than November 1, 2023, but there will be flexibility to launch it six months earlier.

The Ontario Energy Board (OEB) intends to set an ultra-low overnight (ULO) price for May 1. This will introduce a third option for customers billed via Ontario’s regulated price plan (RPP) along with the standard time-of-use and tiered rates.

While the incumbent time-of-use model is based on three price periods — on-peak, mid-peak and off-peak — the new ULO program has four periods and a much greater discrepancy between highest and lowest rates. The price of electricity during the on-peak hours of 4 to 9 p.m., Monday to Friday, will be 10 times higher than the daily overnight price from 11 p.m. to 7 a.m.

On weekdays, the ULO program will have 11 mid-peak hours, from 7 a.m. to 4 p.m. and from 9 to 11 p.m., when prices will be equivalent to the mid-peak rate charged in the standard time-of-use program. On weekends and holidays, the ULO program price from 7 a.m. to 11 p.m. will be in sync with the standard time-of-use off-peak price.

Customers must have smart meters to opt into the program. LDCs will be expected to provide enrollment mechanisms and have billing capability so invoices will show the breakdown of electricity usage in each of the four time periods.

The OEB has also promised to provide more information to customers in advance of the program launch, including updates to its online calculator that allows customers to estimate and compare their costs under the different program options. This is expected to be available on its website by early April.