Learn to love power lines through technology, advocates say
Often, the lines are objectionable to those whose property or landscape they traverse, while transmission line operators ignore the cables for years on end before replacing them with bigger lines, according to a coalition of wires technology companies.
It is an important lost opportunity, says the WATT Coalition, short for “Working for Advanced Transmission Technologies,” a group of companies that make grid products aimed at power line performance.
Digital technologies bolted onto the grid allow controllers to steer power flows away from congested lines or safely increase the energy loads that lines carry, the coalition argues in a policy brief authored by Rob Gramlich, president of Grid Strategies LLC.
But transmission operators and their investors get a higher financial payoff by investing in bigger transmission projects than in less costly add-ons, the coalition says, and that’s where the investment dollars go.
The coalition paper asks the Federal Energy Regulatory Commission to investigate and fix what it calls a bias against transmission line technologies. Even raising the issue would help, it says. “When the industry knows the Commission is ‘watching’ and cares about an issue, companies put their best minds on it. That would help a great deal,” the coalition said.
Technologies that upgrade the capacity and reliability of power lines could reduce an estimated $6 billion in transmission congestion costs added annually to U.S. electricity customers’ power bills, according to the coalition. Transmission line congestion pushes up utility bills because grid operators have to call on higher-cost generation closer to customers when longer-distance connections are overloaded, Gramlich said in an interview.
Technology upgrades would also allow more renewable power to reach customers by overcoming congested pathways from wind and solar installations to customers, Gramlich added. He formerly headed transmission policy for the American Wind Energy Association as senior vice president and interim chief executive. He was recently joined at Grid Strategies by Michael Goggin, who had been AWEA’s senior research director.
Curtailment of wind power delivery because of inadequate transmission affected only about 2 percent of U.S. wind energy output in 2016, according to the Energy Department’s 2016 Wind Technologies Market Report. But in the Midwest and New England, the curtailment percentage was twice the national average. Nationally, curtailment bottled up to an average of 1,360 megawatts of wind capacity, the DOE report said.
Why transmission line technologies don’t get more attention is a matter of money, the coalition says.
There is nothing preventing power companies from using the technologies to improve the workings of existing lines, except that they now make more money building new lines, the paper adds.
The three technologies that could help most are advanced power control, dynamic line rating and topology optimization, the coalition said.
In the same boat
“They all face the same challenge,” Gramlich said.
Power flow controls enable grid operators to “push or pull” power away from overloaded lines, rerouting it to more open paths.
Dynamic line rating (DLR) systems take advantage of sensors that measure conditions on power lines, permitting operators to increase power flows without risking line overloading while also alerting them when to reduce flows.
Topology control technologies automatically reroute power around overloaded transmission lines by switching high-voltage circuit breakers off and on.
The technologies add to an expanding digital grid, which some cybersecurity experts fear is expanding potential attack surfaces on power grids. But the technologies have proved to be reliable and beneficial in a number of pilot demonstration projects, Gramlich said.
FERC’s historic cost-of-service regulation works against these technologies, the coalition said.
It allows utilities to add transmission investment into their transmission rate base — the bucket of capital costs spent on transmission line infrastructure. In general, new lines are approved if they are necessary to meet grid reliability requirements. Utilities are paid according to rate formulas, which typically deliver annual returns of around 11 percent.
“Under this regulatory regime, utilities profit more on large capital investments than on smaller ones that may achieve the same purpose,” the coalition paper said. A $50 million transmission project delivers twice the return of a $25 million one, even if they both deliver the same benefits to consumers.
In addition, some of the transmission technologies are considered operating costs and so are not added to the capital assets bucket. Operating costs are passed through to consumers dollar for dollar, while capital costs get the 11 percent return, the coalition says.
“There are some utilities that are interested in pilots” of the new line technologies, Gramlich said. “National Grid has been doing a lot in this area,” for example, Gramlich said. “They know about it from their sister utility in the United Kingdom. There, they have incentives to adopt them [transmission technologies], and they do.”
In Belgium, a DLR project installed by the power industry technology company Ampacimon in November 2014 has operated flawlessly since then, according to a Transmission & Distribution World magazine report.
“There are some really good examples from transmission operators around the country and [regional transmission organizations],” Gramlich said. “And I think they would be willing to talk and share their best practice experiences, and that would enable these ideas to spread.”
FERC staff is looking at these technologies, and the commission is interested in innovation, Gramlich said. “FERC as the regulator has an interest in seeing these efficiencies play out, even if it’s maybe not prepared at this time to overhaul all of its rules.”