Last year, the US Environmental Protection Agency announced tougher air-quality standards for industrial and commercial coal-fired power plants that will require them to use maximum achievable control technology (MACT) to reduce acid gas and mercury emissions. To be compliant, coal-burning power plants would have to spend millions on new equipment, and this could make coal too expensive for many users.
The EPA’s actions may very well accelerate the energy industry’s move to cleaner fuels. Greenwood Energy is at the forefront of this movement, offering services to power utilities for developing greener power technologies including biomass, fuel cells, natural gas, solar, and hydro. Interestingly, Greenwood also produces a solid, combustible fuel for small-scale, coal-fired plants used to power manufacturing plants and institutional campuses. A Greenwood factory in Green Bay, Wisconsin, converts non-recyclable paper and plastic byproducts of various manufacturing processes into pellets that closely emulate the energy, storage, and handling characteristics of coal. “The pellets have about the same energy value per pound as bituminous coal, but are significantly lower in sulfur and mercury emissions,” says Scott Whitney, the CEO of Greenwood Renewable Fuels, the company’s pellet-making division.
The pellets fuel furnaces designed for coal with, in most cases, only minor modifications to existing fuel-feed systems, operating parameters, and environmental permits. “Our pellets are certified by the US EPA as a non-waste fuel. The feedstock has never been in anyone’s trash can,” Whitney says. “It is not subject to EPA waste incinerator regulations and is classified as a renewable fuel by the states of Ohio and Wisconsin.” The result is a renewable fuel made from non-recyclable material that would otherwise end up in landfills.
The Green Bay plant produces 250 tons of fuel per day that is trucked to large manufacturing plants and university central-power facilities. However, the plant actually has the capacity to produce nearly twice its current output. Greenwood’s customer base is mostly made up of small- and medium-sized coal or solid-fuel boilers to whom Greenwood can supply anywhere from 20 tons to several hundred tons of fuel pellets per day.
Greenwood’s other areas of business also move power generation in a greener direction. The company is developing utility-scale solar-power plants in the United States as well as several Latin American countries. “There is tremendous potential for solar power in Latin America—particularly in Mexico, Panama, and Chile,” says Dennis Loria, Greenwood’s senior vice president of project development. In those areas with high solar insolation and where conventional fuel sources have to be imported, solar can be cost competitive even without government incentives.
Advances in battery technology and manufacturing could provide a boost to solar adoption domestically, Loria says, as the ability to store sun-generated power would address many of the current utility integration concerns. California’s AB 2514 law requiring 2,000 megawatts of storage in the state by 2024 will help kick-start the battery market. “The technology is there now, but the cost is still a challenge for most applications,” Loria says.
Greenwood’s work in developing small-scale cogeneration and fuel-cell plants is also nudging power generation closer to sustainability. Other renewable technologies, such as anaerobic digestion gas produced from organic waste, could be in the company’s future. Indeed, wherever there is an opportunity for greener power generation, you might just find Greenwood.