◊ Part of the ‘wind energy’ series of articles ◊
When wind energy is supplying the grid and there is sufficient energy from lower cost sources to supply load the system operator will need to dispatch generation in accordance with established guidelines. If the appropriate generation is not curtailed, the system will push the excess energy through ties to adjacent jurisdictions.
Based on 2017 hourly flow data from the IESO, Ontario had a net export of 12.5 TWhs of energy. The total wind energy produced in 2017 was 9.3 TWhs.
Did we really need the wind energy in Ontario or was it actually surplus?
The short answer is – maybe.
The long answer is – only the system operators would know. It depends on the relationship between generation and load (demand) at any one time and the configuration of the grid. With their operating experience and sophisticated computer applications, system operators make the necessary determination and take appropriate actions to keep the lights on.
It is likely that some of the energy produced by wind gets exported, however it is extremely difficult to distinguish between electrons from hydro, nuclear, gas, wind and solar because they all look the same.
For the case where Ontario exports power, the market will determine energy prices. In most cases it will be at wholesale cost (HOEP) which is a fraction of the price paid under contractual terms to generators. The difference is paid to generators by Ontario ratepayers through the Global Adjustment.
If the System Operator cannot curtail wind generation during times when energy is surplus, it is economically beneficial for Ontario to sell to adjacent jurisdictions. If energy can be curtailed but the curtailment price is higher than the net export price, it is better to export than curtail.
Derek
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