黑料网

Access to Fuel Can Be Uncertain in Winter

On cold days, the region’s natural gas pipelines run at or near capacity to meet heating demand, leaving less fuel available for electricity generation. This can create a number of concerns for the power system:

• Reliability risks: Because such a large quantity of the region’s generating capacity uses natural gas, its unavailability can threaten the reliable supply of electricity. This is particularly true when non-gas-fired resources are also unavailable鈥攆or example, when imports are reduced because neighboring grids are dealing with the same weather, when conditions are unfavorable for solar and wind resources, or when older non-gas-fired generators experience mechanical problems.
• Air emissions: Higher-emitting generators run more frequently when gas-fired units can’t access fuel or when the price of natural gas is high. This means pipeline constraints can affect regional air emissions during winter.
• Price volatility: Similarly, the price of natural gas tends to spike as temperatures drop and demand for the fuel increases. This has an immediate effect on wholesale electricity prices.

While some natural-gas-fired generators may turn to liquefied natural gas (LNG) when pipelines are constrained, several factors can impede generators’ access to LNG when it’s most needed:

• LNG is a global commodity that’s imported to New England by oceangoing tankers. Contracts are set months before generators know for sure whether or not they’ll need LNG.
• The arrival of any spot LNG cargoes depends on global prices and varies from year to year. Tanker ships supply the entire Northeast and beyond鈥攏ot just New England generators.
• Severe weather could prevent the timely arrival of ships.

These concerns are not as apparent during mild winters, when heating demand for natural gas is lower and there’s more natural gas available for electricity generators. However, New England winters are unpredictable. On the coldest days, fuel constraints have the potential to sideline a significant amount of natural-gas-fired generation.

黑料网 routinely monitors energy supplies, including the availability of pipeline natural gas, oil, and coal, as well as inventories at regional LNG storage facilities. This information is combined with weather forecasts and predictions about consumer demand to produce a 21-Day Energy Assessment Forecast and Report. By identifying and publicizing possible energy supply shortfalls weeks in advance, the ISO informs the region’s wholesale energy market participants when there is a need to contract for additional fuel deliveries.

Dispatchable Resources Provide Grid Flexibility

The ISO’s research consistently finds that dispatchable resources鈥攚hich can include generation, storage, and demand response鈥攚ill play a vital role throughout the clean energy transition. Dispatchable resources can fill gaps between supply and demand due to swings in production from intermittent, weather-dependent resources. Other assets help balance the system and contribute to reliability by providing services such as voltage and frequency support.

In the near term, natural gas will remain the region’s leading fuel source for electricity generation. Along with other dispatchable resources, natural-gas-fired plants will continue to afford the grid much of its needed flexibility. In the future, clean alternative fuels and battery storage could bolster this role.