Mountain of Mulch Grows at Biomass Plant

   Renegy Holdings may not be in the mulch business, but you’d never know it.

Piled on the company’s property is 25,000 tons of high-quality mulch, and that’s only since the beginning of 2009. By the end of the year, that pile is expected to triple in size to around 75,000 tons, with equal amounts expected to be generated in each of the next couple of years.

   “We’re technically not in the mulch business, but by default we happen to be in the mulch business,” says Bob Buckingham, director of business development for Renegy.

   The core business of Renegy is energy generation. It operates the only wood fuel biomass generation facility in Arizona, generating about 25 megawatts, enough to power some 35,000 homes. The power is sold to both Arizona Public Services and the Salt River Project, the state’s two largest electric utilities.

   To generate that power, the plant, located in Snowflake, Ariz.  — where the temperature on the day of this interview hovered well into the triple digits — burns about 500 tons of woody biomass a day.

   Most of that material comes from the surrounding White Mountains, where Renegy has agreements with the U.S. Forest Service and Bureau of Land Management to thin overgrown forests for fire prevention and to eradicate invasive species. It also collects dead and burned timber from the massive Rodeo-Chediski fire of 2002. That wildfire in east-central Arizona charred more than 467,000 acres.

   Renegy also gets material to burn after local green waste is screened and processed in a project that involves the city of Phoenix and Gro-Well Brands, Inc., one of the largest companies offering natural and organic lawn and garden products. The green waste project is being carried out on 20 acres at the city’s Solid Waste Management Facility.

   “The benefits to the city of this operation include diverting this material from the waste stream, and reducing costs associated with hauling,” Phoenix officials say.

   The program also benefits Renegy’s biomass power plant.

   “Everything that’s left after they (Gro-Well) have screened and ground it and taken away their mulch is stuff that resembles, and is, woody biomass,” Buckingham explains. “It’s bigger pieces that wouldn’t be mulch, up to 3 inches in size that have BTUs in it and it burns very well in our boilers. So we do take truckloads of that diverted green material up to our plant as part of our fuel source.”

   Renegy would take even more of the green waste, he says, if it wasn’t so costly to truck to its plant, located some 150 miles from Phoenix.

   “Trucking this material up to Snowflake is not inexpensive,” Buckingham says. “We only truck up a limited amount — less than 5 percent of our usage — from the Phoenix area due to the trucking cost. We could completely fuel the plant with diverted green waste from Phoenix, but because of the expense we only do a small portion of it. The rest of the material we get is up on the mountain where Snowflake is located, within a 25 mile radius of the plant, so the cost of transporting it is much less.”

   The biomass plant was commissioned in June 2008 and according to Buckingham is one of only two such plants to come online in the last 10 years. About 200 biomass plants are in operation throughout the U.S., he says.

   “Biomass is an important piece of the renewable energy formula that will both help meet growing electricity demand and reduce our nation’s dependence on fossil fuels,” said Bob Worsley, chairman and chief executive officer of Renegy at opening ceremonies for the plant. “We are proud of what we have accomplished with the commissioning of our Snowflake plant, and look forward to owning and operating many more such plants . . . ”

   The company says its goal is to become “the leading independent power producer of biomass electricity in North America.

   “We endeavor to apply proven technologies to transform underutilized perpetual and renewable natural resources into clean, sustainable and economical power,” the company says on its Web site. “Through the creation and operation of multiple renewable energy projects across North America, we aim to become part of the solution to fossil fuel dependence and the destruction of our planet.”

   Buckingham says the company is looking at constructing new plants — including one to serve the Phoenix area — in the future.

   “We have several other plants under development right now both in Arizona and the western part of the U.S.,” he says. “All that green waste that is available [in Phoenix] that’s expensive to get up to Snowflake today would be diverted to a newly developed facility closer to Phoenix.”

   The biomass operation involves sorting, grinding and screening wood product. Everything from about one-half inch to 3 inches in length is fed into the boiler and burned; smaller pieces are shunted off to the mulch pile.

   “That’s where I’m getting all my mulch,” Buckingham says. “I screen my material out so that I get rid of all the fine material because I only want the wood chips.”

   The result, he says, is a “very good quality” mulch.

   “We’ve done a complete analysis on it,” Buckingham says. “One of the positive attributes is it’s very low in salts and low in chloride because it’s coming from the forest rather than from an urban setting that might be watered with city water with chlorine in it. Our mulch is very low in salts and chlorides, it’s medium in nitrogen. It’s basically all pine mulch. There’s no city effect that might come out of a landfill . . . Ours tends to be a little purer.”

   Buckingham says no amendments have been added to the mulch.

   “We haven’t done anything to it,” he says, noting that the mulch comes directly from the screening operation.

   “That’s not our business,” he says of the mulch. “Our purpose in screening is to get boiler fuel.”

   Renegy is looking into putting in a bagging operation to market its growing mountain of mulch although “at this point we haven’t developed a formalized market for the mulch,” Buckingham says.

   He points to the current economic crisis — fewer people doing landscaping reducing the demand for mulch — as well as the distance and costs involved in getting the mulch into the Phoenix area as limiting factors.

   “It’s a combination of being at a pretty far distance to get the mulch into the market, transportation wise, and an economy that is not as robust as it might have been a couple of years ago,” he says. “That’s why my mulch is just sitting there. It’s composting nicely. It’s probably turning into a better quality mulch with every month that goes by.

   “As a byproduct of my fuel collection efforts for my biomass plant, I do create a substantial amount of mulch,” he notes, adding, “I’m in the mulch business per se. I have a lot of mulch but I’m not actively marketing it. That’s not my business. My business is making electrons.”