To help meet their company’s goal of a zero carbon footprint by the year 2040, Hubbard Construction Company, headquartered in Winter Park, Florida, recently started using the first all-electric, process heating liquid asphalt distributor, manufactured by E.D. Etnyre & Co. in Oregon, Illinois.

“Etnyre’s Green Distributor can considerably reduce idling time by 25 to 30 percent, which will save about 4.3 tons of carbon annually while also reducing our costs,” said Ian Gianetti, Hubbard’s Regional Equipment Manager. “By not using propane, we can save another 25 tons of carbon annually.”

Hubbard bought the truck-mounted Green Distributor in August from their dealer, Ring Power, headquartered in St. Augustine, Florida. They first used it in repaving a turnpike, then moved it to a 2.5-mile milling and resurfacing job on Alafaya Road in Orlando. Part of Hubbard’s yearly maintenance contract with Orange County, Florida, the three-month project started in September. With crews working during a specific window of nighttime hours, the Green Distributor helps the resurfacing to commence quickly and predictably, while a special lighting system increases safety.

Hubbard’s parent company, Eurovia USA, originally asked Etnyre if they could design an asphalt distributor to heat liquid blacktop without diesel or liquid propane gas. Ring Power and a couple of other Caterpillar equipment dealers provided input in the development process.

Traditional distributor heating systems use burners powered by liquid propane gas or diesel fuel that project fire down a flue to heat the product in the tank while releasing emissions exhaust. Etnyre’s Green Distributor replaces traditional burners and heating tubes with electric resistance heaters that produce no emissions. Two element-style heaters fit into small-diameter heat tubes, allowing the system to sit lower in the tank so it requires only a minimal amount of product for heating.

The electric system provides a “softer” heat source than direct-fired heaters, said Mark Halvorsen, Ring Power’s Senior Paving Products Specialist. “If you overheat the material, it breaks down and separates. Electric heat won’t do that. It’s like induction heat on a stove.”

For Hubbard’s milling and resurfacing project, “It’s a pretty busy road in an urban space so our crews work nights and have to pave what they mill each night,” Gianetti said.

Because the Green Distributor plugs into an electrical outlet at Hubbard’s yard when it’s not on the jobsite, “The start time is a little less,” Gianetti said. “With traditional trucks, you need to warm the tack with a burner system for at least 45 minutes while the truck idles. With the electric truck, the guys don’t have to get there an hour early to heat it up, so it saves on time and labor.”

An onboard, 15k hydraulic-driven generator allows the distributor to reheat material on the jobsite. However, “So far we’re seeing the temperature drop just 7 to 10 degrees during a shift, depending on the temperature outside, and that’s still within the operating range we want,” Gianetti said. “It’s pretty well-insulated, so that eliminates a whole bunch of idling, saving on fuel and our carbon footprint.”

At the end of each shift, crews clean the circulation system to remove residual product before it hardens inside the pump or spray bar. The Green Distributor uses Etnyre’s Smart Clean system, which returns all the solution to the cleaning tank for reuse, recycling, or disposal.

“The cleaning process doesn’t take very long – seven minutes to suck the material back into the tank, then about 10 minutes to circulate the cleaning fluid and clean the bars,” Gianetti said. “We’re told you can run the cleaning fluid for about a month. Eventually we’ll drain it and refill with some new cleaning solution.”

After the cleaning process, Hubbard plugs in the distributor at the yard. A thermostat maintains the temperature and an automatic overheat switch shuts off the burners if the material gets too hot.

“After crews fill the tank back up, the machine heats the material to 170 degrees then stops heating, turning back on if the temperature drops,” Gianetti said. “It takes about $4 to $5 per hour to heat the machine, or about $1,800 per month – but if we’re not using propane to heat it and we’re idling 25 to 30 percent less, we definitely save money, even if it costs a little to keep it heated overnight.”

Because Hubbard performs many of their paving projects, like this one, at night to avoid issues on busy streets, they added red perimeter LED lights to almost every machine in their paving train.

“The lights lay a perimeter of about 5 feet around the machine – basically a red ring that’s pretty bright,” Gianetti said. “There are arcs in the front and rear and red straight lines on the sides. They provide a reference for workers on foot to realize that if they’re on the wrong side of the red line, it’s not a good place to be and they need to move because they could get run over.”

Hubbard sent their perimeter lights to Ring Power, then Halvorsen engineered and fabricated mounting brackets for the front, back, and sides of the Green Distributor.

After Ring Power’s new prep team installed the lights, “We had to make sure the angles were right, so we put it in a dark room and aimed them,” Halvorsen said. “We went through the wiring and put them all on toggle switches. Everything bolts on so they can change it.”

In addition to Hubbard’s Green Distributor in Orlando, Eurovia USA’s fleet of 80-plus tack trucks on the east coast currently includes two Green Distributors with Tampa Pavement Constructors (a division of Hubbard) in Florida and one with Blythe Construction in Charlotte, North Carolina.

“The goal is to replace all of the tack trucks within our parent company with electric trucks by 2030,” Gianetti said. “Based on our capital expenditure projections at Hubbard, we’ll probably buy two more from Ring Power in 2023 and then continue buying at least one or two each year.”

To meet Eurovia’s goal of a zero carbon footprint, “In addition to the Green Distributors, we’re looking at other electric and hybrid equipment; we’re converting a lot of our asphalt plants to an alternate fuel source instead of waste oil, which takes a little more to burn; we’re trying to reduce the amount of water in our base materials so we don’t have to use as much heat to burn out the water; and we’re looking at recycling a lot of our material back into the mixes we make,” Gianetti said. “We have a pretty lofty goal so we’re attacking it in many different ways.”

Photos courtesy of Jason Rundle, Ring Power Corporation