With a decision pending on whether the Bonneville Power Administration (BPA) will build the I-5 Corridor Reinforcement Project, BPA issued a request for offers (RFO) on non-wires grid management tools to see what options are available to relieve grid congestion in the Northwest, a BPA spokesperson told TransmissionHub April 29.
The April 26 RFO seeks adjustments in generation capacity, demand-side management (DSM) resources or other technologies to provide transmission loading relief during the summer along the South of Allston (SOA) transmission corridor, which is generally along I-5 between Portland, Ore., and Vancouver, Wash., the BPA spokesperson noted.
Responses, which can include incremental capacity, DSM resources and decremental capacity – or reduced generation – are due May 26, according to the RFO. The RFO seeks terms only for the summer months of July through September, starting July 1, 2017, with a one-summer minimum term and a five-summer maximum term.
For the incremental and decremental capacity, BPA would pair increases in generation close to where load is served with reduced generation elsewhere to provide transmission relief on the SOA path, the BPA spokesperson explained.
BPA will consider offers between 25 MW and 250 MW, according to the RFO. BPA said in the RFO that it “will prioritize offers that provide maximum, least-cost counter flow” on the SOA path.
A bidders’ conference is planned for May 9 to address any questions on the RFO, BPA said.
The RFO, with final agreements expected to be reached no later than Dec. 31, is expected to lead to a five-year pilot program on non-wires solutions for transmission relief on the SOA path, BPA said in an April 26 statement.
BPA has previously explored non-wires solutions but has not found a set of solutions that would provide the congestion relief on the SOA path to negate the need for the new I-5 transmission line, BPA said in the statement. BPA recognizes that technologies are evolving, and new advancements could provide a solution that pushes out the need to build the 500-kV transmission line, BPA said.
Because much of the generation used to meet load in the Portland and Vancouver region is north or east of there, it must travel along the SOA path that has not been reinforced with additional capacity since the 1970s, BPA said in the statement. During periods of high demand, the amount of power travelling along those lines can approach or exceed safe operating limits, BPA said.
The responses to the RFO may help inform BPA Administrator Elliot Mainzer as he considers whether BPA will build the I-5 Corridor Reinforcement Project, the BPA spokesperson said. When BPA issued the final environmental impact statement (EIS) for that project in February, BPA said that a decision is expected to be reached by the end of the year and that is still the plan, the spokesperson said.
Regardless of the decision on the I-5 transmission line, “we’re still going to need congestion management tools” to relieve the transmission power flows in the Portland and Vancouver corridor, the BPA spokesperson said.
The I-5 Corridor Reinforcement Project would increase the north-south transmission capacity in southwest Washington and northwest Oregon with the addition of a 79-mile, 500-kV line from Castle Rock, Wash., to Troutdale, Ore. In the final EIS, BPA said its preferred route for the project is the Central Alternative, using Central Option One, with an estimated cost of $459m.
BPA has said that without any physical or operational changes to the system, transmission constraints along the SOA path could lead to brownouts or power outages as early as 2021.
In the final EIS, BPA said that construction would take five years, making for a tight construction timeframe if a decision on building the line is reached in late 2016.
“While construction of a physical line would resolve capacity limitations along this corridor for the foreseeable future, it is a costly undertaking,” Jeff Cook, vice president of planning and asset management for transmission at BPA, said in the April 26 statement.
“We want to make sure that we make the right investment at the right time for BPA and the people of the Northwest,” Cook said, adding that advances in congestion management may allow BPA to defer the need to build the line in the immediate future.