Power Systems Update: New England grid operations through recent bitter cold weather and preparation for winter storm

January 7 Power Systems Update 

As of Sunday, January 7, New England’s bulk power system continues to operate reliably during this extremely frigid weather covering New England and the Northeast. Nevertheless, managing the region’s power system through these conditions continues to be challenging, primarily because of fuel availability.

During this extreme cold, some power plants have either tripped offline or had to reduce their output, while other oil-fired and dual-fuel generators are quickly depleting their fuel supply. As a result, ISO New England has taken steps to conserve fuel by ‘posturing’ units, which means that the ISO is postponing the operations of certain generation for later in the day or week, and using other generating resources instead to produce electricity. Consequently, some facilities will operate ‘out-of-merit’ which means these resources will be compensated to operate when the ISO requires them.

While the ISO is continually assessing the reliability of the system, other conditions continue to make grid operations difficult. Pilgrim Nuclear Power Station remains out of service, some oil-fired generation is nearing emissions limitations, and other power plants are awaiting fuel deliveries that were postponed because of Thursday’s storm. But these deliveries will not begin before tomorrow at the earliest.

With temperatures expected to warm up this week, the ISO expects power grid conditions to improve for the region, and offer a window for fuel replenishment. Such fuel replenishment is critical to handle any future cold snap. In the meantime, the ISO will continue to issue these updates if system conditions warrant.

ISO New England implemented Master/Local Control Center Procedure No. 2 (M/LCC 2) on Wednesday, January 3. M/LCC 2 remains in effect because of the extremely cold weather, and concerns about fuel supplies and unexpected resource outages. M/LCC2 is an operating procedure issued when an abnormal condition exists or is anticipated. When market participants receive an M/LCC 2 alert, they are expected to cease any routine maintenance, construction or test activities on their equipment that could jeopardize the reliability of the power system.

A Cold Weather Watch is also in effect for today, Sunday, January 7. A Cold Weather Watch is issued when extreme cold weather and a capacity margin of 1,000 megawatts or more are forecasted; sufficient capacity is expected to be available to meet demand and reserve requirements. More information about cold weather watches, warnings, and events is available: Cold Weather Watch, Cold Weather Warning, or Cold Weather Event.

January 5 Power Systems Update

New England’s bulk power system continues to operate reliably. Currently, there are sufficient generating resources available to meet consumer demand and maintain power system reliability this weekend, barring an unexpected outage of any large system resource. While the ISO is continually assessing the reliability of the system, we will be challenged to deal with major contingencies under these cold weather conditions. In addition, the ISO doesn’t expect generator emission limitations to impede weekend grid operations.

Past the extremely cold weather this weekend, however, the ISO remains concerned about the distribution of fuel inventories across the region and emission limits for some generators for the remainder of the winter. Because of the region’s heavy reliance on oil-fired power plants for the past 12 days, several are running low and fuel replenishment will be critical for these facilities, especially if the region encounters another cold snap soon after this one. Yesterday’s Winter Storm Grayson has delayed delivery of oil to refill generators’ storage tanks. While the ISO cannot provide information about specific generators, a few power plants have reported that they are nearing their emissions limitations.

The cold weather continues to affect wholesale energy prices as well as the types of power plants that are being used to meet demand. High demand for natural gas for heating is causing natural gas pipeline constraints that are resulting in high natural gas prices, which impacts wholesale electricity prices offered by natural gas-fired power plants. As a consequence, both oil- and coal-fired power plants are generating at much higher levels than is typical. Despite this change in fuel mix, most power plants have been called to operate ‘in merit’, which means that New England’s wholesale electricity prices have been set by the competitive marketplace. Yesterday, Pilgrim Nuclear Power Station tripped offline, reducing the amount of generation coming from nuclear power. While no immediate reliability issues have resulted, this outage does further challenge the region’s fuel availability risk because we will need to rely more heavily on other generating resources to meet consumer demand and meet overall grid reliability.

ISO New England issued Master/Local Control Center Procedure No. 2 (M/LCC 2) on Wednesday, January 3, because of yesterday’s storm. M/LCC 2 remains in effect and will likely be in place for this weekend and the duration of the extremely cold weather because of concerns about fuel supplies and unexpected resource outages. M/LCC2 is an operating procedure issued when an abnormal condition exists or is anticipated. When market participants receive an M/LCC 2 alert, they are expected to cease any routine maintenance, construction or test activities on their equipment that could jeopardize the reliability of the power system.

The ISO has also issued a Cold Weather Watch for today, tomorrow, and Sunday, January 8, as the extreme cold temperatures are expected to persist. Watches are generally issued just two days in advance. A watch is issued when extreme cold weather and a capacity margin of 1,000 megawatts or more are forecasted; sufficient capacity is expected to be available to meet demand and reserve requirements. More information about cold weather watches, warnings, and events is available: Cold Weather Watch, Cold Weather Warning, or Cold Weather Event.

January 4 Power Systems Update

New England’s bulk power system is currently operating reliably. As a precautionary measure, the ISO has issued Master/Local Control Center Procedure No. 2 (M/LCC 2) alert. It was issued late yesterday in light of the impending winter storm as well as the forecasted extreme cold after the storm and continued concerns about fuel supplies and unexpected outages. M/LCC2 is an operating procedure issued when an abnormal condition exists or is anticipated. When market participants receive an M/LCC 2 alert, they are expected to cease any routine maintenance, construction or test activities on their equipment that could jeopardize the reliability of the power system.

As is standard practice before and during big storms, the ISO participates in conference calls with other ISOs, the North American Electric Reliability Corp., and the Northeast Power Coordinating Council, to provide updates on the status of the power systems that may be affected. In New England, we expect to have sufficient capacity and fuel available and expect to be able to weather the storm without running up against significant emissions limits, but concerns remain the same regarding fuel availability and emissions limits throughout this protracted cold spell and the rest of the winter.

The ISO has issued a Cold Weather Watch for Friday and Saturday as the extreme cold temperatures of earlier this week are forecasted to return. Watches are generally issued just two days in advance. A watch is issued when extreme cold weather and a capacity margin of 1,000 megawatts or more are forecasted; sufficient capacity is expected to be available to meet demand and reserve requirements. More information about cold weather watches, warnings, and events is available: Cold Weather Watch, Cold Weather Warning, or Cold Weather Event.

Through this weekend, we expect to have sufficient capacity and fuel available to meet demand, barring unexpected outages.

The cold weather continues to affect wholesale energy prices as well as the types of power plants that are being used to meet demand. High demand for natural gas for heating is causing natural gas pipeline constraints that are resulting in high natural gas prices. As a consequence, both oil- and coal-fired power plants are generating at much higher levels than is typical. The high fuel prices are pushing up wholesale power prices as well. In general, a snow storm doesn’t affect forecasted demand for power, unless there are local power outages caused by stormy conditions.

Pilgrim tripped offline earlier this afternoon due to storm conditions. While it is an unexpected outage, there are no immediate reliability issues to the local area. However, this outage does further challenge the region on fuel availability because we need to rely on other generating resources to meet consumer demand and meet overall grid reliability.

January 3 Power Systems Update

Throughout the recent cold weather blanketing the region, New England’s bulk power system has been operating under normal conditions. However, the cold weather is having an effect on wholesale energy prices as well as the types of power plants that are being used to meet demand. High demand for natural gas for heating is causing natural gas pipeline constraints that are resulting in high natural gas prices. As a consequence, the price of generators burning natural gas has risen higher than the price of generators burning oil or coal, so a significant portion of the region’s electricity is being generated by power plants that use oil. With this price inversion, both oil- and coal-fired power plants are generating at much higher levels than is typical. The high fuel prices are pushing up wholesale power prices as well. Nuclear power, coal, dual-fuel units running on oil, and liquefied natural gas (LNG) are also providing power system support.

The winter reliability program is again providing critical support for reliability. The program offers incentives for oil-fired generators to stock up on oil before winter began and to replenish their fuel supplies as necessary prior to March 1. However, the sustained cold is requiring round-the-clock usage of some of these oil-fired generators and some are already running low on fuel. Based on current weather forecasts and economic trends, the ISO expects a continued need to rely heavily on oil-fired generators through the duration of this period of cold weather. As oil inventories are depleted, replenishment of these fuels will be important given the uncertainty around weather and future fuel demands for the remaining two months of the winter period.

The ISO has issued a Cold Weather Watch for Friday, January 5, as the extreme cold temperatures are forecasted to return. Cold Weather Watches are generally issued just two days in advance; indications are a watch will be issued for Saturday, January 6, as well. This watch is issued when extreme cold weather and a capacity margin of 1,000 megawatts or more are forecasted. Sufficient capacity is expected to be available to meet demand and reserve requirements. More information about cold weather watches, warnings, and events is available: Cold Weather Watch, Cold Weather Warning, or Cold Weather Event.

Preparations for the impending storm

As is standard practice before big storms, the ISO participates in conference calls with other ISOs, the North American Electric Reliability Corporation (NERC), and the Northeast Power Coordinating Council (NPCC), to provide updates on the status of the power systems that may be affected. And as a precaution, ISO-NE has declared Master/Local Control Center Procedure No. 2 (M/LCC 2), beginning at 4:00 p.m. on Wednesday, January 3. This procedure calls for routine maintenance, construction, and testing on bulk power system resources to be postponed if it could affect the reliability of the power system. 

The ISO expects to have sufficient capacity and fuel available to meet demand during the upcoming winter storm, and emissions limitations are not expected to be a factor through this coming weekend. However, the storm could cause further delays in the replenishment supply chain–for example, fuel deliveries from ground transportation or via barge. As with natural gas, some types of oil are in great demand for heating as well as power generation; and deliveries can become more difficult or impossible in stormy conditions. With forecasts for continued cold through next week, the ISO will increase the frequency of generator fuel surveys and continue its close communication with oil-fired power plants, natural gas pipeline operators, and neighboring power systems.