The outlook for the reliability of Ontario’s electricity system remains positive for the next 18 months, the Independent Electric System Operator says in its latest 18-Month Outlook, with adequate domestic generation and transmission to supply Ontario’s demand under normal weather conditions. But the IESO acknowledges that, “[u]nder extreme weather conditions, the reserve levels that reflect current planned generator outages are below requirement for a combined total of 16 weeks over the period of May to September 2018. If extreme weather conditions materialize, the IESO may need to reject some generator maintenance outages to ensure that Ontario demand is met during the summer peak.”
Ontario’s peak demand remains relatively flat, thanks to conservation savings, growing embedded generation output and the Industrial Conservation Initiative (ICI) that have offset the increased demand from population growth and economic expansion. That trend is expected to continue over the forecast horizon.
Some 1,300 MW of new supply – 1,000 MW of gas, 275 MW of wind and 25 MW of hydroelectric – is expected to be connected to the province’s transmission grid over the Outlook period. By the end of the period, the amount of grid-connected wind is expected to increase to about 4,500 MW and grid-connected solar is expected to remain at 380 MW.
By the end of the Outlook period, embedded wind capacity will exceed 600 MW and embedded solar will surpass 2,200 MW. Overall contracted embedded capacity will reach 3,300 MW over the Outlook horizon.
As reported in its second quarter Progress Report on Contracted Electricity Supply, for the period ending June 30, 2017, the IESO was managing 29,542 contracts, with a combined capacity of 27,402 MW, spread across eight fuel types and three fuel groups as shown in Figure 1. The total amount of contracted capacity in commercial operation was 24,192 MW, while 3,210 MW remained under development.