NDP Leader Andrea Horwath is asking the Premier to reveal her government's plan to meet northwestern Ontario's energy needs.
Horwath says concern still lingers about the planned conversion to biomass of the Thunder Bay generating station, even after it burned its last lump of coal.
Critics don't believe the biomass supply for the plant will be large enough to generate the amount of electricity needed in northwestern Ontario.
Energy Minister Bob Chiarelli says a recent meeting determined the planned conversion is doable.