TORONTO - Ontario's environment watchdog says the difference between peak and off-peak electricity prices is not nearly wide enough to encourage people to conserve energy.

Environmental commissioner Gord Miller's conservation progress report echoes findings of the auditor general, who said last month that the narrow difference undermines time-of-use pricing as an incentive for ratepayers to shift to off-peak.

Miller says after reviewing dozens of other countries who have time-of-use pricing structures a ratio of four or five to one is necessary for significant savings, and in Ontario the current ratio of 1.8 to one is insufficient.

A spokeswoman for the Ministry of Energy says the Ontario Energy Board is reviewing price ratios.

Jennifer Beaudry notes the ministry has a long-term conservation target of reducing gross demand for electricity by 16 per cent in 2032, which is more than all of the power used by the city of Toronto in 2013.

Miller says the province has no interim electricity conservation targets, and without those it will be difficult for him to keep tabs on their progress toward a goal 17 years away.