ISO-NE 2022 generation portfolio emissions report

New England's electric power generation fleet emitting slightly less carbon dioxide in 2022 relative to 2021, according to the grid operator's 2022 ISO New England Electric Generator Air Emissions Report.

ISO New England operates the regional transmission grid and the wholesale market for electricity. In support of this role, ISO-NE tracks the portfolio of generation resources used in the region, as well as the resources' emission characteristics.

According to ISO-NE, New England generation emitted 33,382 kilotons of carbon dioxide in 2022, a decline of two-tenths of a percent relative to 2021. The grid operator reports an average 2022 emission rate of 643 pounds of CO2 per megawatt-hour of New England generation. 

Over longer time scales, air emissions from New England's power plants have decreased significantly. "From 2001 through 2022, CO2 emissions fell by 37%, NOx emissions fell by 79%, and SO2 emissions fell by 98%."

While carbon dioxide emissions decreased slightly again this year, sulfur dioxide (SO2) emissions increased to 3.38 kilotons, climbing over 60 percent relative to 2021. The grid operator attributes the sulfur emissions to increased reliance on fuel oil for electric generation:

More electricity came from oil-fired generators in 2022 than in the previous four years combined. At 1,845 GWh, production from these resources in 2022 was eight times higher than in 2021. Oil has a high sulfur content, so SO2 emissions rise when these resources produce more power.

The chart below shows the region's generation portfolio on a monthly basis for 2022; the red and black bars at the top of each month's column represent oil and coal use. The largest blue bars represent natural gas, while the largest orange bars represent nuclear power.

ISO-NE attributes increased use of oil for power generation to "record high natural gas prices associated with the Russia-Ukraine conflict, and thus an increase in regional reliance on oil versus natural gas." The grid operator also says that decreases in coal generation largely offset the increased oil use for purposes of CO2 and NOX emissions.

Maine Climate Council legislation enacted

Newly enacted Maine legislation establishes the Maine Climate Council to advise the Governor and state Legislature on ways to mitigate the causes of, prepare for and adapt to the consequences of climate change, and calls for significant reductions in the state's overall greenhouse gas emissions.

On June 26, 2019, Maine Governor Janet Mills signed into law An Act to Promote Clean Energy Jobs and To Establish the Maine Climate Council. One set of provisions in the new law establishes a requirement that Maine reduce gross annual greenhouse gas emissions -- to at least 45% below the 1990 gross annual greenhouse gas emissions level by 2030, at least 80% below the 1990 gross annual greenhouse gas emissions level by 2050, and on track to meet the 2050 target by 2040. The law requires the Department of Environmental Protection to adopt rules to ensure compliance with these levels, and authorizes the Department of Transportation to adopt similar rules.

Crucially, the rules must prioritize greenhouse gas emissions reductions by sectors that are the most significant sources of greenhouse gas emissions, as identified by the United States Energy Information Administration and in the department's biennial reports, taking into account gross greenhouse gas emissions reductions achieved by each sector since 1990 and the cost-effectiveness of future gross greenhouse gas emissions reductions by each sector. While the electricity sector has largely been decarbonized, transportation and heating lag significantly. Maine's transportation sector was responsible for 53 percent of the state's greenhouse gas emissions in 2017, with heating taking the next greatest share. Meanwhile, electricity generation in Maine accounted for just 9 percent of the state's greenhouse gas emissions.

The law also creates a 39-member Maine Climate Council, with a subcommittee for scientific and technical matters and various working groups. The Council must meet at least every three months, report annually to a legislative committee, and prepare an updated climate action plan by December 1, 2020 and every four years thereafter. The climate action plan must include a clean energy economy transition plan.

 

ISO-NE 2018 CELT projects future energy usage declines

The operator of New England's bulk electric grid projects that both energy usage and peak demand from the utility grid will decline slightly in the region over the 10-year period between 2018 and 2027, primarily due to the deployment of energy efficiency measures and behind-the-meter solar arrays.

ISO New England Inc. is the regional transmission organization responsible for the electric grid and electricity markets across most of New England. On April 30, 2018, ISO-NE published its 2018-2027 Forecast Report of Capacity, Energy, Loads, and Transmission, or CELT Report. The grid operator prepares annual CELT reports which describe the assumptions used in ISO system planning and reliability studies. These assumptions include the total generating capability of in-region resources, as well as a long-term forecast for growth in energy consumption and peak demand.

According to ISO-NE's 2018 CELT Report, overall regional electricity use will grow 0.9% annually over the 10-year period. But when energy efficiency and behind-the-meter generation are taken into account, ISO-NE's forecasts for both regional energy usage and peak demand project slight declines over the 10-year period. The grid operator projects an annual decrease in net energy usage by -0.9% annually, with seasonal peak demands projected to decline by -0.2% to 0.7% annually. ISO cites "continuing robust installation of energy-efficiency measures and behind-the-meter solar arrays throughout the region" as the primary factors driving this decline.