Virginia State Corporation Commission (SCC) staff on Jan. 11 said that it does not oppose Virginia Electric and Power’s (Dominion Virginia Power) request for a certificate of public convenience and necessity (CPCN) to rebuild the Carson-Rogers Road 500-kV Line #585.
However, staff said that it believes that the use of factory-dulled galvanized steel structures, at an incremental cost of about $75,522, may be a reasonable, cost-effective way to minimize the visual impacts of the new galvanized steel structures.
As noted in staff’s report filed with the SCC, the existing, approximately 28-mile line was completed in 1972, and according to the company, the existing line is projected to be in violation of the PJM Interconnection generator deliverability criterion following the loss of the 500-kV Carson-Rawlings Line #511.
The generator deliverability test (GDT), also called the generator deliverability analysis, is a criterion established by PJM to test the strength of a transmission system in terms of its ability to reliably deliver the output of generators located within a specified area to the rest of the PJM system during peak load, staff said.
The staff report also noted that after 40 years of continuous operation, the line is nearing the end of its useful life and will require replacement of its “COR-TEN” weathering steel towers in order to maintain reliable service.
The company is seeking a CPCN to rebuild the line, wholly within existing right of way (ROW), with new galvanized steel structures that average 10 feet taller than the existing strucutres, staff said.
The estimated cost of the rebuild is $52.9m, of which about $30m would be allocated to Virginia customers, staff said.
Staff said that it has reviewed the information provided in the company’s application regarding the GDT, and has verified the power flow studies included in the application, as well as those provided in response to interrogatories. Based on those reviews, staff said that it has determined that the company’s analyses are reasonable and that the company has demonstrated a need for the project.
Staff also said that it agrees with the company’s assessment that while reconductoring alone is sufficient to resolve the GDT violation, it does not resolve the company’s long-term need to meet the requirements of its transmission planning criteria related to aging infrastructure. Accordingly, staff said that it does not oppose the replacement of the line’s structures as a component of the rebuild project, since that would provide the added benefit of addressing projected end-of-life criterion violations.
Staff also said that the company provided four alternative solutions to resolve the generator deliverability violation, but that none of them would resolve the long-term need to replace the deteriorating infrastructure on the existing line. for instance, the company proposed to build a new 500-kV line between its Carson and Rogers Road stations, parallel to the line, with a length of about 32 miles. Including real estate acquisition and required work at the Carson and Rogers Road stations, the company estimated that that alternative would cost about $69.6m.
Noting that it requested the company to provide costs for alternative finishes on the proposed towers – in order to ensure completeness of the record – staff said that the company noted that it has not proposed, and does not support, the use of factory-dulled galvanized steel structures, because the company is concerned with the steel manufacturer’s ability to ensure proper application and removal of the chemical dulling treatment on the galvanized steel.
According to the company, if the procedures are not completed properly, the chemical dulling treatment could compromise the galvanized coating on the steel and impact the coating service life. Staff added that it is aware that other utilities use the chemical dulling treatment on galvanized structures, and that it is not aware of any negative impacts associated with such treatment.
Among other things, staff said that while no public comments have been received in the proceeding, in other recent rebuild cases, the SCC has received significant public comment regarding the visual impacts of galvanized steel. If the SCC determines that the company should mitigate the visual impacts of galvanized steel, staff said it believes that use of the factory-dulled galvanized steel structures may be a cost-effective and reasonable means for such mitigation.
Dominion Virginia Power is a subsidiary of Dominion Resources (NYSE:D).