Wednesday, January 23, 2019

ISO-NE Tariff Changes Make Renewables More Easily Dispatchable

By William Opalka

The Federal Energy Regulatory Commission has accepted revisions to the ISO-NE Tariff that make wind and hydropower resources more readily dispatchable (ER15-1509).

The changes “will minimize the need to use manual curtailment processes and thus, provide for a more economically efficient use of these resources,” FERC wrote.

The recent increase in the integration of variable renewable resources in relatively remote areas of the transmission system has caused increased congestion, ISO-NE said. These resources do not have direct control over their net power output, are not currently electronically dispatchable and must be manually curtailed to manage congestion, which is inefficient.

ISO-NE said the new method would manage localized congestion through Do Not Exceed (DNE) Dispatch Points — the lesser of the maximum output level at which the resource would operate in economic dispatch, or a reliability limit representing the maximum output consistent with reliability constraints.

FERC said the changes are particularly important as these resources are increasing in New England. While there are 878 MW of wind and 321 MW of hydro generation operating in the region, there are more than 4,000 MW of these renewables in the RTO’s interconnection queue.

“We agree with ISO-NE that these changes will improve price formation, particularly in areas that have a high penetration of renewable resources and limited transmission capacity, and system reliability because of the reduced reliance on manual curtailments,” the commission said.

FERC, however, rejected Tariff language that would have excluded wind resources from participating in regulation and reserves markets, agreeing with renewable energy developers that a “blanket exclusion” was not justified. “Eligibility for providing these services should be based on capability and performance characteristics rather than categorical exclusions,” according to the order. Rules should be developed through a stakeholder process, the commission said.

FERC also gave hydro resources that do not currently have remote terminal units an additional year to comply because they have to undertake additional steps to become DNE Dispatchable Generators, compared with resources that already have the equipment.

ISO-NE’s proposed Tariff revisions are conditionally accepted effective April 10, 2016, with a compliance filing due in 30 days.

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