From 2002 through June 2012, 400 transmission projects required for power system reliability have been put into service in New England, representing $4.8bn in infrastructure improvement, according to ISO New England (ISO-NE).
Of those, eight are major 345-kV transmission projects, ISO-NE said Nov. 2, adding that these transmission upgrades reinforce critical areas of the grid where demand is highest, such as in southwest Connecticut and Boston, as well as areas that have experienced significant load growth, such as northwest Vermont.
ISO-NE President and CEO Gordon van Welie said in the statement that the 2012 Regional System Plan (RSP), which was approved by ISO-NE’s board of directors, “reviews projects that have made New England’s power grid more reliable and efficient and identifies future system improvements and initiatives.”
ISO-NE said the plan noted that additional transmission upgrades identified for meeting reliability requirements are under construction, have been approved in state-level siting proceedings, or are being prepared for state siting proceedings.
These include the Maine Power Reliability Program (MPRP), upgrades in southeastern Massachusetts and the New England East-West Solution (NEEWS), which is made up of several transmission projects in Massachusetts, Connecticut and Rhode Island.
According to the RSP, the MPRP, for which Maine state regulators have approved most of the components, establishes a second 345-kV path in northern Maine and adds new 345-kV lines in southern Maine. ISO-NE is conducting an analysis of the extent to which transfer capability through Maine has been changed because of the project, which is scheduled for completion by early 2015.
On NEEWS, ISO-NE said the Springfield and Rhode Island components of the project are scheduled for service by 2014. The need for the Interstate Reliability Project, part of NEEWS, has been reconfirmed and the preferred solution is unchanged. Also, the need for the Central Connecticut Reliability component of NEEWS remains under consideration as part of the Greater Hartford-Central Connecticut study.
Also, the Long-Term Lower SEMA project, which received siting approval in May, addresses system reliability concerns in the lower southeastern Massachusetts area, including Cape Cod, and is scheduled for completion in September 2013.
ISO-NE also addressed the “RSP Project List,” which is a summary of needed transmission projects for the region and is updated at least three times per year. As of June, the total estimated cost of transmission upgrades proposed, planned and under construction, including MPRP and NEEWS, was about $6bn.
On northern New England transmission, ISO-NE noted that with the Northeast Reliability Interconnection in service, New England and New Brunswick have two 345-kV interconnections leading into a 345-kV corridor at Orrington, Maine, and eventually tying into Massachusetts.
Over the past several years, the addition of generation in Maine and New Hampshire, along with the area’s limited transfer capability and limited transmission expansion, have increased the likelihood of many northern New England interfaces operating near their limits.
The ISO has identified projects that address transmission system performance issues, and some address subregional reliability issues and have the ancillary benefit of improving the performance of major transmission corridors.
Among those projects are the MPRP and the Bennington, Ascutney and Georgia 115-kV substation rebuild projects in Vermont. Those substation rebuild projects are needed for resolving contingencies that could result in area voltage collapse.
ISO-NE also addressed southern New England, or the Massachusetts, Rhode Island and Connecticut transmission system. While recent improvements have been made, the southern New England system continues to face thermal, low-voltage, high-voltage and short-circuit concerns under some system conditions.
Transmission projects are underway in various stages in southern New England, including NEEWS and the “Central/Western Massachusetts Upgrades,” which calls for adding a second 230/115-kV autotransformer and replacing four 230-kV breakers at Bear Swamp, for instance.
ISO-NE also said transmission solutions continue to be put in place where proposed generating or demand-side resources have not relieved transmission system performance concerns.
Furthermore, to address potential system reliability concerns associated with the upcoming unavailability of Entergy’s (NYSE:ETR) Vermont Yankee nuclear power plant, transmission upgrades at Flagg Pond have been installed to address potential thermal overloads if the plant is unavailable.
Highlighting resource mix, energy consumption
ISO-NE said in its statement that more than 14,430 MW of new generation have been built in the region since 1997.
Furthermore, more than 2,000 MW of demand resources are part of New England’s resource mix, and more than 3,600 MW are expected to be available by 2015.
The most recent forward capacity market auction done in April showed that the region should have adequate resources to meet consumer demand through 2015/2016, but the capacity resources in the northeast Massachusetts/Boston area are projected to marginally meet demand for that area for that time period.
ISO-NE also said that energy consumption is projected to grow an average 0.9% annually over the next 10 years, while summer peak demand is expected to grow by 1.5% per year.
Among other things, ISO-NE said that between 2000 and 2011, electricity generated by natural gas-fired power plants increased from about 15% to more than 50%, while electric energy produced by oil units declined from 22% in 2000 to less than 1% in 2011, and energy from coal plants fell from 18% in 2000 to about 6% in 2011.