Both conductors for the entire length are three cables bundled together; this is done to reduce the effects of EM interference and enhance the power line's performance.

9  The HVDC line's converter stations will be replaced as part of a project to repurpose the Intermountain Power Plant as a hydrogen-burning facility.

[14] Finally, DC circuitry has been chosen for Path 27 because the cost of transmitting power over its distance is lower than with AC,[13] which is best economically suited for shorter stretches.

[12][17] Asea, a multinational electrical supplier based in Sweden, managed the framework and supplies for Path 27, and was a chief contributor for the power line's installment.

[20][8] The cooperative was founded around this mission:Among its objectives is funneling excess energy to communities in Southern California; Path 27 was built to fulfill that purpose.

[22] The earliest concept of Path 27 likely originated in 1973, coinciding with an energy crisis of that decade plaguing the U.S. During that year, after the U.S. Bureau of Reclamation warned of a forthcoming energy shortage, representatives for the Utah-based Intermountain Consumer Power Association (ICPA) convened with Southern California localities in a quest for newer power sources and for investors.[10]: 1, ch.

[28][j] Various American contractors were commissioned for certain aspects and segments of the line; for instance, one entity from Georgia built 239 miles (385 km) worth from Adelanto, California to Moapa, Nevada, and another from Mississippi took on the remaining 250 miles (400 km) till Delta;[23] but perhaps the most notable obligation for this turnkey project rested upon Asea,[a] who imported the conductive cables and pieces for the galvanized steel-lattice support pylons[10]: 44, ch.

[23] Newspapers reported that rocky, jagged terrain often posed challenges for accessibility and had likely necessitated copious excavation and even dynamiting.

[23] The line achieved revenue service in July 1986[6] after the ignition of the power plant's first coal-burning unit, even though a document by LADWP attests that it might have been energized as early as December 1985.

At the behest of LADWP and Southern California Edison, ABB Group and Hitachi Energy modernized the transmission line in 2008 and 2011, respectively, with improved control and protection technology[k] alongside supplemental filters and cooling systems at each terminal.

A single cable carrying such high voltage would produce particularly strong radiation in the form of a corona discharge[14] that can deprive electrical energy and cause EM interference on radio and communication devices.

[39] Each cable is made of aluminium strands enveloping a steel core for strength and durability,[40] and the composite measures 1.8 inches (46 mm) in breadth.[10]: 44, ch.

[41][l] Both sides of Path 27 feature a converter station, which bridges electrical power between AC and DC circuitry and is ubiquitous to HVDC projects worldwide.

[20][43] The heart of the conversion process transpires in clusters of electronic valves that procedurally modify the flow of electricity in a manner similar to switches.

[48] The valves are affixed on tall insulators that separate them from the interior walls, floor, and ceiling; done to hinder induction and premature grounding, as well as aid cooling.

[58][59] Even with safeguards and a substantive fault tolerance, failures on the line can and do occur, thence grounding becomes a workaround for continued reliability of the system.

At each grounding point is an array of buried conductive rods that form an electrode, marking the actual transition into the earth for the current.

Within the electrodes for Path 27 are sixty rods[s] arranged in a circular rim about 3,000 feet (910 metres) in diameter[55] and spaced evenly for the best result.

[57]: 82  Additionally, the coke regulates heat that the rod naturally emits when a current is induced;[57]: 89  this is to mitigate the electrode's impact on the surrounding environment.

At the center is a small structure perched on the surface called a terminal house,[61]: 42  which is also equipped with a transmitter that helps technicians monitor the electrode's performance.

[57]: 20 The converters are linked to the electrodes by a pair of conductive cables, each measuring 1.407 square inches (908 mm2) in thickness, to enable physical contact with the earth.

[57]: 135  Starting at both termini, the electrode line runs atop Path 27's main pylons in lieu of shield wires before branching off along a standalone set of steel utility poles.

[66][61]: 45  Uniquely, Adelanto's electrode line travels underground for its final two miles (3.2 km) approximately till the grounding site.

The DC line ventures through legions of dry basins and high mountains in the state due southwest; all the while crossing Utah Routes 21, 56, and 18; before reaching Nevada about 5.5 miles (8.9 km) north of Arizona's northwestern corner, simultaneously entering the Mojave Desert.

Upon traversing the McCullough Range, it descends into Ivanpah Valley, missing Primm in its north and crossing Interstate 15 again; shortly thereafter, it enters California.

North of Mesquite, both are joined by a 500-kV line connecting the decommissioned Navajo Generating Station; the three travel somewhat within eyeshot of Interstate 15 until a solar park near Crystal.

An assortment of 500-kV transmission corridors then follow Path 27 through Las Vegas Valley toward another collection of solar farms outside Boulder City.

[7] In a renewal project announced by LADWP, the plant will be replaced with a gas-powered facility specially tailored for harvesting hydrogen by 2025,[71] and paired with at least two solar farms on nearby parcels.

The renewal project also calls for both converter stations to be replaced and activated by June 2026,[31][43][75] as well as improvements to Path 27 to lengthen the power line's service life.