Wind and hydropower generators in New England now are required to offer their power into the independent system operator’s day-ahead energy market.
Beginning June 1, ISO-New England requires wind and intermittent hydro-powered generators with a capacity supply obligation to start offering in the market. Three years ago, ISO-NE launched the Do Not Exceed (DNE) Dispatch Project that enabled these resources to participate in the Real-Time Energy Markets and begin taking electronic dispatch instructions from ISO New England for the first time.
These changes facilitated the ability of renewable resources to set real-time prices, improved price formation, and increased system use of low-cost renewables in areas with limited transmission capacity.
Requiring DNE dispatchable resources to participate in the Day-Ahead Energy Market will lead to a more accurate commitment of resources and an improvement in the price convergence between the day-ahead and real-time markets, according to the ISO-NE release. The change will also help address curtailment issues, which occur when the maximum potential output of a group of resources exceeds capacity, leading to the resources being dispatched down or even off line in order to avoid overloading the transmission system.
Now, power from these resources that clears in the Day-Ahead Energy Market will not be curtailed until all the real-time-only generations are curtailed during a period with transmission constraints. In essence, obtaining a position in the Day-Ahead Energy Market gives the resources a better chance of being dispatched and not curtailed.