The Future Is Now: Examining Construction's Power Alternatives

(California Builder & Engineer) At the center of any construction alternative power discussion is diesel. Diesel remains the go-to power on jobsites. According to the Diesel Technology Forum, 98 percent of construction's energy use in the United States comes from diesel.

But with global initiatives underway to reduce carbon emissions to net zero by 2050, it is up to construction industry manufacturers to find ways to lessen diesel's carbon impact. A range of solutions is being considered:

Unlike some sectors, construction does not rely on a core piece of equipment, but rather on a vast fleet that ranges from mini excavators to massive off-highway trucks. And a jobsite can be anywhere from midtown Manhattan to rural Wyoming. Which is why so many diesel alternatives are being offered, including electric, hydrogen, biodiesel, and other biofuels. And, over the next decade or so, one (or more) of these alternatives will establish themselves as having the greatest long-term potential.

“What's coming? The answer is probably all of them,” said Jeremy Harsin, Construction Market Director at AEM member company Cummins. “The combination of duty cycle and available infrastructure is going to decide what wins out, but they're probably all going to have their place in the world.”

Current construction equipment prototypes use hydrogen in two ways: either as a fuel cell that charges a battery-electric machine or to fuel an internal combustion engine. In a hydrogen fuel cell, hydrogen and oxygen react to produce electricity, with water as its only by-product. In the second way, hydrogen is used as a direct engine fuel, much like diesel.

While hydrogen must be compressed and transported at low temperatures, “it's a portable fuel so you can get it to where it's needed,” Sleight said.

But infrastructure challenges are also part of the hydrogen story. There are few hydrogen fueling stations and almost all of them — approximately 70 — are in California. Construction equipment powered by hydrogen fuel cells and hydrogen-fueled engines are — at least at this point — in the prototype stage.

Hydrogen-powered engines also illustrate another way to reduce engine emissions: modify a conventional engine to be able to burn cleaner fuels. According to proponents, this approach does not require wholesale changes of jobsite practices, machine componentry, or fueling infrastructure.

This approach offers scale, since many of the components are similar. And it holds promise for off-highway engines since Cummins commonly adopts cross platform technologies, Harsin said.

Current prices and world political stability issues aside, diesel remains the construction stalwart.

Despite its “dirty diesel” perception, Cummins says it is worth a reminder that compared with Tier 1 engines, today's Tier 4 Final engines offer a 96 percent reduction of oxides of nitrogen and a 97 percent reduction in particulate matter. READ MORE