The Brattle Group’s assessment of the Eastern Interconnection Planning Collaborative’s (EIPC) December 2011 Phase 1 report found that the data confirms a substantial need for interregional transmission in the coming decades, but that the methodology used by EIPC was designed more as a learning exercise than an actual plan for strengthening the transmission network.
The Phase 1 report is one of the major ongoing reviews of high-voltage transmission needs across entire electrical interconnections funded under the 2009 economic stimulus legislation, the Working group for Investment in Reliable and Economic electric Systems (WIRES) added May 30.
WIRES said it asked Brattle to conduct an evaluation of the EIPC data to date, in efforts to help stakeholders and the public better understand the challenges to transmission planning that EIPC faced as well as the details of the EIPC process.
The EIPC stakeholder steering committee in December 2011 completed Phase 1 of a 2.5-year study funded by the U.S. Department of Energy (DOE) to look at potential Eastern generation and transmission scenarios and the grid’s potential long-term needs, WIRES said.
According to WIRES’ preface to the assessment, Phase 1 focused on the changing profile of electric generation and documented transmission congestion. Sensitivity studies were done to identify transmission expansions needed between regions and “super regions” to reduce congestion to 75% and 25% of the base levels. They showed that, in some scenarios, from 37 GW to 122 GW of new energy transfer capability may be needed to reduce congestion between regions and “super regions.”
Phase 2 will focus mainly on the need for transmission within regions and between regions where indicated by the Phase 1 analysis. However, WIRES added, of the three scenarios chosen, two have zero or minimal transmission added between regions. This necessarily leaves inter-regional planning processes to be addressed by the follow-on procedures under FERC Order 1000.
WIRES also noted that in one of the three chosen scenarios to be examined in Phase 2, stakeholders chose to assume that additional inter-regional transmission was not needed, in order to model intra-regional development of renewable resources. This assumption, WIRES added, will understate the sizeable need for inter-regional transmission. In the “business as usual” scenario, stakeholders chose to model a generational build-out assuming no inter-regional transmission over and above what was included in the 2016 base case in spite of the analysis that suggests that it may be valuable to add between 3 GW and 22 GW. “We do not believe this Phase 1 assumption is realistic,” WIRES added. “This should be revisited in follow-on studies.”
Phase 2 of the study effort is designed to integrate generation build-out scenarios identified in Phase 1 and address corresponding reliability needs across the Eastern Interconnection. It does not evaluate the economics of transmission investments nor take into account key transmission benefits beyond reliability, like congestion relief, load and resource diversity, cleaner resources, the “insurance” value under extreme conditions, reduced losses and more optimal use of generation. It was not designed to do so, WIRES added.
Among other things, Brattle’s assessment noted that while Phase 1 results show significant transmission congestion and potential transmission needs that will need to be studied outside the EIPC process, EIPC assumed the 2016 base-line transmission system did not include all transmission already planned across the Eastern Interconnection.
Also, many of the larger congestion-reducing scenarios were not chosen by stakeholders for Phase 2 analysis, which may warrant follow-up analysis if further congestion relief would be economic.
Brattle also said Phase 2 will address transmission needs to reliably accommodate generation additions and retirements identified in Phase 1, noting that follow-on analyses will be needed.
WIRES said in its statement that the Phase 1 report will yield benefits in the future because experts in transmission and systems planning from dozens of states have learned how to work together toward optimal investment in the country’s electric system.
“We hope that the EIPC process will inform the efforts to comply with FERC’s Order No. 1000 and the congestion studies currently underway at the [DOE] to implement National Interest Electric Transmission Corridors,” WIRES President Jolly Hayden said in the preface to the assessment. “However, that makes it even more important that we identify the governing assumptions and limitations of the EIPC process, the factors considered and not considered, and possible next steps in planning and developing a 21st century grid.”
EIPC Executive Director David Whiteley told TransmissionHub May 30 that EIPC appreciates WIRES’ review.
He said of WIRES, “They understand what the purpose of the study is and…support the findings and believe that they’re appropriate for the purpose and the limitations of the study that were set forth.”
Whiteley noted that others have reached conclusions on the Phase 1 report as well. “We appreciate the fact that they have interest in the work and have found the results useful,” he said.