Comparing electric and diesel powered portable plants

Paul Smith, the director of international sales and marketing at Astec Aggregate & Mining Group, hears the buzz. So do Keestrack’s Peter McGeary and IRock’s Fred Gross.

Diesel has long been the dominant power option for portable plants, but electric power has come on strong in recent years. Smith regularly hears from customers around the world about their interest in electric, and interest here at home continues to grow in select markets.

“The trend continues and seems to be accelerating a bit,” Smith says.

Interest and use of electric is growing for a number of reasons, according to Smith. Some markets are more restrictive on emissions for fossil fuel-type plants, he says, while maintenance on today’s cleaner diesel engines can be a bit more complex.

Additionally, some producers and contractors are realizing the true benefits of electric plants.

“Most people would generally agree that uptime is about 10 percent higher with an electric plant versus a diesel plant,” Smith says. “That’s not to say [diesel plants] don’t have a place, but if you’re going to be using diesel plants it’s probably good to plan ahead for that. The engines do have problems if not properly maintained.”

McGeary, who oversees Keestrack’s sales in North America, pinpoints other electric power advantages.

“Electric motors are more efficient at producing torque for crushing and screening,” he says. “This is a great asset. Electric motors last much longer than hydraulic motors and require much less maintenance.”

McGeary also describes the work environment around electric plants as “much cleaner.”

“There’s no need to worry about hydraulic pumps, hydraulic motors or hydraulic pipes breaking and spilling oil all over the ground,” he says.

One of the ongoing portable plant trends Gross identifies is a desire for cleaner operations. But cleanliness isn’t necessarily the deciding factor in whether a customer selects an electric or diesel plant.

“The bottom line is all recycle people, all aggregate producers want the lowest cost to produce per ton,” says Gross, director of sales and business development at IRock.

The in-between solution

Aggregate producers and contractors certainly have a number of things to consider when exploring their next portable plant purchase. One option some users around the world consider as they ponder a transition to electric is the diesel-electric hybrid.

“I am hearing more people ask about hybrid machines, but the U.S. market is slow to move on this,” McGeary says. “I think it will take some government incentive to get them to look seriously at hybrid machines in the future. We are selling a lot of hybrid machines into Europe mainly because the diesel fuel is much more expensive than in North America.”

According to McGeary, European users buy hybrids for reasons beyond the cost of fuel. For example, there’s chatter in Europe that some cities may someday ban diesel vehicles from their roads.

“When customers hear that, they ask themselves will this law follow through into the workplace,” McGeary says. “Some of the end users want to get ahead of the game and are now purchasing our hybrid machines.”

Like McGeary, Smith is seeing more diesel-electric hybrids in the field.

“They’re using the [diesel] engine to position machinery but then bring in the line power,” Smith says.

Undoubtedly, the European market is one worth keeping an eye on.

“We all anticipate the restrictions are going to get tighter, and that’s driving cleaner fueling systems,” Smith says. “There was this trend there where everyone was going to these self-contained diesel plants. But now, people want to utilize the lean benefits that portable plants offer yet also have the benefits of the electric power sources.”

Digging deeper

Still, don’t expect diesel to disappear anytime soon in the United States.

Gross, for one, expects both diesel and electric plants to have a place here in the foreseeable future.

“Diesel portable plants are not going to disappear,” Gross says. “If we eliminate diesel power, our country comes to a screeching halt.”

Of course, some U.S. markets are more progressive than others at steering users away from diesel through rules and regulations.

“If you’re a contractor in California and you want to pursue a job on a highway project with portable equipment, it could take a long time if you’re trying to do this with diesel engines,” Smith says. “That’s an extensive, timely process that limits your ability to be profitable.”

Geographically, Smith expects electric to take off first in U.S. population centers.

“The East Coast and West Coast are going to be facing more headwinds,” he says. “We’re seeing that in New England, in places like Seattle and Portland, [Oregon]. When you get out to the more rural areas, there’s not as much restriction. It’s really driven by local legislation. There is some federal [legislation], but a lot of it is local.”

Contractors who are continuously on the move are under more environmental pressure than aggregate producers with fixed sites, Smith adds.

“It’s more difficult for contractors to work within city limits with diesel machinery,” Smith says. “One loophole seems to be if a contractor comes in with electric power, they seem to be able to circumvent the engine permits – and they’re coming in with mobile assets. Fixed assets seem to require more permitting.”