Whitepaper: 08.06.2012

Renewable Energy Trends

The Role of Biomass and Other Renewable Energy Sources in the Sustainability Era

More than likely, you have heard the outcry for more sustainable sources of energy as the Earth’s natural resources continue to deplete. In his State of the Union address, U.S. President Obama proposed that by 2035 the U.S. will generate 80 percent of our electricity from a diverse set of clean energy sources — including renewable energy sources like wind, solar, biomass and hydropower; nuclear power; efficient natural gas and clean coal. With only 2 percent of the world’s oil reserves under U.S. control, the need for new sources of energy is evident.

In recent months, McCarthy has seen a variety of construction opportunities arise in the renewable energy market, particularly in the biomass, cogeneration, and solar and photovoltaic arenas. Let us take a more in-depth look at these projects.

Biomass: The Energy-Producing Forest Fire Preventer
First, what is biomass? Biomass, as defined by the Biomass Power Association, is carbon neutral electricity generated from renewable organic waste that would otherwise be dumped in landfills, openly burned, or left as fodder for forest fires. Some examples of biomass include forest residues, yard clippings, wood chips and even municipal solid waste.

Although not a new source of energy — prior to the Civil War, the U.S. used biomass, primarily in the form of wood, for 91 percent of the nation’s energy consumption — biomass provides over half of the renewable energy in the U.S., roughly 8,500 megawatt (MW) a year. Currently more than 80 biomass facilities exist in 20 states, reducing carbon emissions by more than 30 million tons each year and providing 14,000 jobs nationwide. More of these facilities are coming online every year, including the University of Missouri’s 100 percent biomass-fired boiler set to be operational in fall 2012.

The $75 million project designed by Sega Inc. of Overland Park, Kan., and being constructed by the joint venture of McCarthy and CB&E Construction Group of St. Louis, replaces a traditional coal-fired boiler with the 100 percent biomass-fired version. Not only does this help meet anticipated growth needs — the new boiler will produce 150,000 pounds of steam per hour, more than a 20 percent increase from the boiler it replaced — it also allows the university to meet its sustainability initiatives.

One such initiative is Chancellor Brady Deaton’s signing of the American College and University Presidents’ Climate Commitment in 2009, along with 650 other higher education leaders. Through this commitment, the university pledged to reduce carbon emissions by 30 percent from 2008 levels by 2016, a goal that depends largely on reducing the amount of coal burned at the power plant.

“With this boiler we expect to displace over 25 percent of our coal consumption with regionally supplied biomass,” stated Gregg Coffin, superintendent of the university’s power plant. “It’s a pretty significant jump in biomass use considering we’re currently at less than five percent.”

The decision to move to the biomass boiler got its roots in 2005 when Coffin and a group of campus researchers explored possible biomass fuels to co-fire in the plant1. In 2006, corn cobs were tested in the plant boilers followed the next summer by woody biomass from mill waste, development clearing and discarded pallets. The challenge with the new biomass boiler was sourcing the 100,000 tons of biomass the boiler will use annually, 16 times more than the 6,000 tons being sourced previously. The university has contracted with Foster Brothers Wood Products of Auxvasse, Mo., as its primary fuel supplier. The initial fuel will be various sources of waste wood streams, and the university is researching other viable sources, such as forestry management and thinning efforts, agriculture residues, and specifically grown energy crops, including short rotation woody (like willow and poplar), miscanthus and switchgrass.

“We are tapping into the resources here at the university,” Coffin explained. “The university forestry department has been actively involved with the project, helping us source sustainable woody biomass. They’re interested in supporting a managed forestry thinning effort to improve the health and value of our forests.”

In total, the U.S. biomass power industry removes over 68.8 million tons of forest debris annually, improving forest health and dramatically reducing the risk of forest fires. Additionally, the process diverts millions of tons of waste material from landfills and open burns.

Cogeneration: Efficient Creation and Use of Heat and Power
Another renewable energy source receiving attention these days is cogeneration, such as the project recently awarded to McCarthy for the Department of Veterans Affairs (VA) in Texas. Located at the VA Dallas Medical Center, the $23 million project is a stand-alone 4.7 MW combined heat and power (CHP), cogeneration (COGEN) facility in the VA’s nationwide renewable energy program.

Cogeneration, or combined heat and power (CHP), is not a new technology. It may sound complex to someone who is unfamiliar with it, but the concept is fairly simple. Most electrical energy is generated by burning a fuel source and, by means of a turbine or a boiler, generating electrical energy. This is the case with cars: the alternator/generator operates to run the car’s electrical system and recharge the battery. As most drivers know, the engine compartment gets hot when the motor runs because when the car generates power and electricity, it also generates heat.

Usually that heat disappears into the atmosphere and is lost. When the same energy production takes place for a building, CHP “captures” that heat and uses it to generate hot water and steam or chilled water by using absorption chillers. That steam/water has obvious domestic uses for kitchens, showers and laundries among other purposes. The CHP process not only converts the waste energy typically lost from the power generation process, but it also avoids the need for a separate energy source that would be required to power a boiler or a chiller to deliver water for the facility’s needs. In simple terms, CHP offers a two-for-one solution.

McCarthy is constructing a system similar to the VA Dallas project at Grossmont Hospital in La Mesa, Calif. The $34 million, 18,000-square-foot central energy plant replaces decades-old equipment and is projected to save millions of dollars in energy costs and provide a reliable source for up to 95 percent of the hospital’s electricity needs. The new equipment will also reduce the hospital’s emissions of harmful greenhouse gas pollutants by 90 percent.

Solar/Photovoltaic: The Sunnier Side of Renewable Energy
Many owners, however, lack the land, capital or general desire to build and operate their own biomass plant or COGEN facility. For them, remaining options for renewable energy include wind, geothermal, and solar and photovoltaics (PV). Although solar and PV only contributes 1 percent of the renewable energy in the U.S., it continues to be the most logical choice for many clients to satisfy sustainability and renewable energy needs.

Arizona Public Service Company (APS) is one such example. The team of McCarthy’s Southwest Division in partnership with MC Industrial, Inc., an independent McCarthy company, recently commissioned a 17MW solar photovoltaic plant in Gila Bend, Ariz., developed by SOLON Corporation and owned/operated by APS.

Located on 145 acres of land with more than 93,000 photovoltaic panels, this system generates enough solar energy to power more than 4,000 homes. The panels are arranged on more than 100 SOLON single-axis trackers. This design enables the solar panels to follow the sun across the sky, making the plant more efficient than static-mounted panels typically seen on rooftops.

Energy from the solar plant will go toward meeting the Arizona Corporation Commission’s Renewable Energy Standard. This project is part of APS’s AZ Sun Program, expected to have 100 MW online by 2014 and to create more than 1,000 Arizona construction jobs.

“Through the AZ Sun program, we have been able to move quickly to begin building new solar power plants to complement our other generating resources,” said Don Robinson, APS president and chief operating officer. “We expect these plants to provide clean, reliable energy to our customers for at least the next 30 years.”

Whether you or your company is as focused on renewable energy as the University of Missouri, Department of Veterans Affairs or APS are, the reality is that this industry will only continue to swell with impending action dates, legislation and the continued shift to more clean energy sources. For more information on any of these energy sources, please visit http://energy.gov/science-innovation/energy-sources/renewable-energy.

Ehm, Greg. University Sees Biomass as Future for Energy Generation, Biomass Magazine,
November 2011 (accessed July 6, 2012).

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