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2017 forecast of capacity, energy, loads, and transmission is published by ISO-NE

Energy usage will decline slightly and peak demand will remain flat over the next 10 years

On May 1, 2017, ISO New England published the 2017-2026 Forecast Report of Capacity, Energy, Loads, and Transmission (CELT). The report is a primary source for assumptions used in ISO system planning and reliability studies. It provides a snapshot of the New England power system, including:

  • The number of megawatts (MW) with capacity supply obligations resulting from the 11 Forward Capacity Market (FCM) auctions held to date, as well as the total generating capability of resources in the region
  • The breakdown of the region’s generators by fuel type
  • A link to the listing of transmission projects proposed, planned, and under construction
  • The long-term forecast for growth in energy consumption and peak demand, including the contributions of energy efficiency and behind-the-meter solar facilities

The long-term forecast for electricity use is developed each year using state and regional economic forecasts, 40 years of weather history in New England, results of both the ISO’s energy-efficiency (EE) forecast and solar photovoltaic (PV) forecast, and other factors. The ISO calculates a gross forecast and then applies the EE and PV forecasts to develop a net forecast.

The 2017 CELT projects that energy usage will decline slightly in New England and peak demand will remain flat over the 10-year period. The primary factors are continuing robust installation of energy-efficiency measures and behind-the-meter solar arrays throughout the region, as well as a slightly lower forecast for economic growth in New England.

CELT projections for 2017 to 2026

Gross forecast not including EE and behind-the-meter PV:

  • Overall electricity use in New England is expected to grow 0.9% annually over the 10-year period, from the expected 140,583 gigawatt-hours (GWh) this year to 152,593 GWh in 2026
  • Peak demand under normal weather conditions of about 90°F (the “50/50” forecast) is expected to rise annually at a rate of 1.0%, from 29,146 megawatts (MW) this year to 31,820 MW in summer 2026 (peak demand is a measure of the highest amount of electricity used in a single hour)
  • Peak demand under extreme summer weather (the “90/10” forecast), such as an extended heat wave of about 94°F, pushes the gross forecast for peak demand up to 31,529 MW in 2017 and 34,531 MW in 2026—an average annual growth rate of 1.0%

Forecast including latest EE and behind-the-meter PV forecasts:

  • Overall electricity use is expected to decline, by -0.6% annually, from 126,786 GWh this year to 119,680 GWh in 2026
    • EE is projected to save the region an average of 1,923 GWh annually from 2021 through 2026 (EE savings committed through Forward Capacity Market obligations are counted for the first four years of the forecast, from 2017 through 2020)
    • PV is projected to produce about 1,894 GWh of total annual energy savings in 2017, rising to about 4,338 GWh in 2026.
  • Peak demand under normal weather conditions is expected to fall slightly, by -0.07% over the 10-year period, from 26,482 MW this year to 26,310 MW in 2026
    • EE is expected to shave about 264 MW, on average, off peak demand each year
    • PV is expected to contribute a reduction of peak demand of about 575 MW this year, rising to 1,035 MW in summer 2026
  • Peak demand under extreme summer weather is expected to grow slightly, by about 0.1% annually, from 28,865 MW in 2017 to 29,021 MW in 2026


2016 energy and demand

Looking back at 2016, actual energy usage dropped 2.0%, from 126,955 GWh in 2015 to 124,382 GWh last year.

In 2016, actual demand peaked at 25,596 MW on August 12, 2016. Without the energy-efficiency measures installed in New England, as well as reductions by demand-response resources, price-responsive demand-side resources, and behind-the-meter solar resources, the peak would have come in at about 28,504 MW.

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