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What do a heliophysicist and our power grid have in common?


April 24, 2014 – A NASA scientist is launching a 1- to 2-year pilot project this summer that takes advantage of high-voltage power transmission lines to measure a phenomenon that has caused widespread power outages in the past, and even crashed Hydro-Quebec’s transmission system: geomagnetically induced currents, courtesy of a flatulent sun.

GICs typically occur 1 to 3 days after the sun unleashes a coronal mass ejection (CME), explains NASA, which is a “gigantic bubble of charged particles” that can carry up to 10 billion tons of matter. CMEs can accelerate to several million mph as they race across space. Should a CME slam into Earth’s magnetosphere, the impact causes electromagnetic fluctuations, resulting in geomagnetic storms on the planet.

These storms increase electric currents that, in turn, drive the fluctuations in Earth’s magnetic field near the ground, adds NASA. These surface currents can flow through any large-scale conductive structure, including powerlines, oil & gas pipelines, undersea communications cables, telecom networks and railways.

This is important stuff, because an extreme example of a GIC occurrence was the magnetic storm of March 1989 which, according to NASA, was one of the largest disturbances of the 20th Century. This event precipitated the collapse of Hydro-Quebec’s transmission system, causing the loss of electric power to more than six million people.

Enter heliophysicist Antti Pulkkinen of NASA’s Goddard Space Flight Center: he and his team are installing scientific substations beneath high-voltage power transmission lines operated by Virginia’s Dominion Virginia Power to measure GICs in real time.

“In essence, we’re tapping into a very large antenna,” Pulkkinen said. “The high-voltage lines are the antennae. During solar storms, violent changes in the electric current occur in near-space, which then are sensed by the transmission lines.”

The team is creating three substations, all equipped with commercially available magnetometers capable of measuring the variable magnetic fields associated with GICs. Once inserted inside a protective, watertight housing unit, the team will bury the gear 4 feet into the ground; two directly below Dominion Virginia Power’s high-voltage lines and the third 1 to 2 miles away (to provide reference measurements).

In addition to gathering data important to the power industry (especially if it’s expanded nationwide, as currently planned), the project will allow heliophysicists to reverse engineer the data to learn more about the conditions in Earth’s upper atmosphere that lead to the generation of GICs during severe space weather events, explained Pulkkinen. “Not only will this benefit the utility industry, it also benefits science.”

Photo 1 shows Antti Pulkkinen of NASA’s Goddard Space Flight Center. Photo 2, courtesy NASA Solar Dynamics Observatory, shows a strong solar flare from April 2013, accompanied by a coronal mass ejection (CME) headed toward Earth.