Should unexpected generator or transmission line outages occur, the ISO can call on resources held in reserve, import emergency power from neighboring regions, ask businesses and residents to voluntarily conserve electricity, or implement emergency procedures to stabilize the grid. Climate change has caused weather to become more volatile and less predictable, increasing the potential for system operators to resort to these actions.
Peak demand forecast, typical weather
Peak demand forecast, above average weather
Available capacity expected
All-time highest summer peak demand (set on August 2, 2006)
Annual energy use is lower now than it was in the early 2000s, but levels of peak demand—the highest amount of electricity used in a single hour—have not fallen. New England’s power system is planned and operated to serve demand during those peak hours, even if annual use is not historically high.
Though New England has over 4,800 MW of solar photovoltaic (PV) capacity installed—most of it behind the meter (BTM)—these systems produce their highest output in the early afternoon hours. The increase of solar power in New England has pushed the peak hour of grid demand later in the day, when the sun is lower in the sky and production from solar PV systems is also lower. Rather than peaking during the mid-afternoon, as was customary during the summer before PV installations became more widespread, demand for grid power now tops off in the early evening hours.
Energy efficiency (EE) measures and BTM PV are forecasted to reduce peak grid demand in summer 2022 by about 2,100 MW and 900 MW, respectively.
|1||Implement Power Caution and begin to allow depletion of 30-minute reserves|
|2||Declare Energy Emergency Alert (EEA) Level 1|
|3||Request voluntary load curtailment of market participants’ facilities|
|4||Implement Power Watch, a notification that additional OP 4 Actions may be taken; if conditions warrant, issue a public appeal for voluntary conservation|
|5||Schedule Emergency Energy Transactions and arrange to purchase energy and capacity from other control areas|
|6||Implement voltage reductions of 5% of normal operating voltage requiring more than 10 minutes Declare Energy Emergency Alert (EEA) Level 2|
|7||Request resources without a capacity supply obligation to provide energy for reliability purposes|
|8||Implement a voltage reduction of 5% of normal operating voltage requiring 10 minutes or less|
|9||Request activation of transmission customer generation not contractually available to market participants during a capacity deficiency, and request voluntary load curtailment by large industrial and commercial customers|
|10||Implement Power Warning and issue urgent public appeal for voluntary conservation|
|11||Request state governors’ support for ISO appeals for conservation|