PORTLAND — Delays in installation, testing and activation of electrical systems will push back delivery of the largest destroyer ever built for the U.S. Navy from this summer to November, officials said Tuesday.

While the future USS Zumwalt is 94 percent complete, the complexity of the project requires more time for tests and activation aboard the 610-foot, electric-drive warship, said Cmdr. Thurraya Kent, a Navy spokeswoman.

The more than $3 billion warship, under construction at General Dynamics’ Bath Iron Works shipyard, will sport advanced automation to reduce crew size and a stealthy shape designed to minimize its visibility on enemy radar.

“General Dynamics Bath Iron Works and the other Navy contractors continue to work hard on test and activation of the lead ship, as well as construction on the two follow-on ships,” said shipyard spokesman Matt Wickenheiser. The shipyard deferred questions on schedule and cost to the Navy.

Delivery of the second warship in the class, the Michael A. Monsoor, will be delayed by a few months to November 2016, while the third and final ship remains on schedule for delivery in December 2018, the Navy said.

Such delays aren’t unusual on a first-in-class military system. And the General Accounting Office previously expressed concerns that the Navy was trying to incorporate too much new technology into the ship, which is the first electric-drive surface combatant built for the Navy since a line of destroyer escorts in the 1940s.

The Zumwalt utilizes a pair of turbines similar to units from the Boeing 777 to provide the muscle for two main generators, which along with two auxiliary units produce enough electricity to light up about 10,000 homes.

The warship features plenty of additional innovations beyond the stealthy shape and electric propulsion: A new gun with rocket-propelled projectiles; new radar and sonar systems; and a new hull shape.

Work on the electrical systems is part of the reason for the delay, Kent said. “The shipyard performance in electrical trade work is behind plan due to complexity of the … all-electric ship and the particular demand it has created for skilled electricians shipyard-wide,” she said Tuesday in a statement.

Jay Wadleigh, president of Machinists Local S-6, disagreed that there’s a shortage of skilled electricians, noting that electricians met their targets despite a projected shortfall of 40 electricians last winter.

Instead, the delays result from the complexity of the ship and design additions and alterations during construction, Wadleigh said. “The Navy would love to have it in the fleet, but they’d love to have it built correctly first. With as much as they’ve invested in it, I’m sure they want it right and not rushed,” he said.