ERCOT readies to integrate a large future influx of wind generation and finds need for new, more flexible resources to provide ancillary services – preferably a zero-to-five-minute ramping...
T&D investments prioritize reliability and load growth.
the region’s transmission grid. NU brings its proposed new projects to the attention of ISO New England technical committees, which include planners from other New England utilities. Once the ISO gives its approval, projects proceed to state and local siting reviews.
“That’s a big change in the process. We used to identify one problem or one project, perhaps a new line or a substation at the intersection of line A and B,” Aylsworth says. “Now we’re replacing the old break-and-fix model. We’ve adopted ISO New England’s philosophy. The solutions are much more comprehensive. We don’t want to under or over-build.”
Pepco Holdings has a similar working relationship with PJM, which oversees the grid-planning process in 13 states and the District of Columbia.
“We’re a member of PJM and it has ultimate responsibility for the system,” Gausman says. “But we have our own planning organization that monitors our parts of the system and reviews the (grid enhancement) recommendations from PJM. Since there are many utilities working with PJM, you tend to take a longer view of the planning horizon. In our case, we look ten years out.”
Pepco’s largest project is the $1.2 billion Mid Atlantic Power Project (MAPP), a 230-mile transmission line that will originate in Northern Virginia, cross southern Maryland and the Chesapeake Bay, and then travel up the Delmarva Peninsula and into southern New Jersey.
“We’ve made significant local upgrades to meet load growth, but there hasn’t been significant bulk-transmission capacity additions in the eastern portion of PJM in many years. You can do the relatively small local projects, but you’re always at the brink of the system’s capacity,” Gausman explains. “In recent years we haven’t always been able to call on the most economical generation. So you run (more costly) generation in the region when you need that capacity. That congestion costs the region hundreds of millions of dollars annually.”
In addition to relieving congestion and bringing additional power to its service territories, MAPP ultimately will work in concert with two other transmission projects currently under development: the Potomac-Appalachian Transmission Highline (PATH) and Trans-Allegheny Interstate Line (TrAIL).
The $1.2 billion PATH project, being developed by Allegheny Energy and American Electric Power (AEP), is scheduled to begin operations in 2012 and will run from West Virginia to Maryland. The $850 million TrAIL project is being developed by Allegheny subsidiary Trans-Allegheny Interstate Line Co. It’s scheduled to begin operations in 2011 and will run from southwestern Pennsylvania to northern Virginia. Both are being developed to make it easier for PJM to move energy from west to east.
“Both of those projects will relieve congestion points in Pennsylvania, Maryland and West Virginia. But we didn’t feel they went far enough,” says Gausman. “They’ll relieve congestion points in those states, but in our analysis they’re not sufficient enough to bring energy to our service areas. MAPP will relieve congestion points further east. So yes, the three projects will complement each other.”
Like NU, Pepco conducted studies to examine the limitations to its existing transmission system and came up with proposed solutions.