Dominion Energy wants to rebuild 17.7 miles of a 500 kV power line through Augusta County to meet the electricity load of its western Virginia customers, and as long as it’s rebuilding the line, increase the height to accommodate an additional 230 kV line should the need for it ever arise. Building a double-circuit structure would add $6.1 million to the project but save between $44 million and $55 million if the utility had to come back later to add the second transmission line.
Local landowners, distressed by the visual impact on their property, oppose the higher line, and they want Dominion to pay between $1.3 million and $2.5 million extra to add a coating that would give the bright galvanized steel a brown color.
In a ruling issued earlier this month, State Corporation Commission hearing examiner Ann Berkebile ruled that the rebuilding of the existing Dooms-Valley 500 kV line is justified by the public convenience and necessity but that spending the additional money for taller towers is not. Further, she found that the expenditure of additional money to chemically dull the towers is warranted. The case now goes to the SCC’s three judges for a final ruling. Wrote Berkebile:
The ability to address a need that could arise at some time in the future at an incremental increased cost (and at a lower cost than is likely to be incurred should a future need arise) does not outweigh the actual detrimental impacts of significantly taller towers upon the scenic and historic assets of August County. Under the circumstances, I conclude that the Commission should approve the use of less expensive, shorter lattice towers for the rebuild.
Berkebile’s findings come at a time in which Dominion and other electric utilities are investing massive sums to upgrade their electric grids. Over the next 15 years, Virginia likely will see the retirement of more coal-fired plants and the construction of more solar farms and gas combustion-turbine plants. An open question is whether Dominion will be able to re-license its four nuclear power units. The grid, designed for a traditional configuration of electric-power generation also will need to be upgraded to meet a new configuration in which intermittent solar and wind sources play a role.
Dominion consulting engineer Peter Nedwick identified three scenarios that would support the need for the additional 230 kV line through Augusta County, according to Berkebile’s summary of the testimony. In her report, however, Berkebile did not discuss the scenarios or assess how likely any one of them was to occur. SCC staff, she stated, was “unable to verify” a need for taller towers to accommodate a 230 kV line.
In his testimony, Nedwick also cited three instances in which single-circuit structures proved inadequate and Dominion was required to come back and rebuild transmission lines within a double-circuit structure. Given the relatively low cost of preserving the flexibility, summarized Berkebile, “he continued to support the double circuit option as a means of maximizing the use of existing [Right of Way] while maintaining flexibility to meet future demands and changes in [North American Electric Reliability Corporation] Reliability Standards.
The SCC staff supported the chemical dulling option to reduce the visual impact of the pipelines on the Augusta County landscape. A relatively new product, Natina, gives galvanized steel a brown color. According to a Dominion engineer, testing shows that the coating will not maintain a uniform appearance over time. Also, it will increase rust, be difficult to paint over, and hinder the natural development of a patina on the steel girders. Alternatives include COR-TEN weathering steel, hot-dipped galvanized steel, a chemically dulled (pre-dulled) steel.