The position of students and environmental activists is that we need energy that is renewable, clean and affordable from solar, wind, hydroelectric, geothermal and biomass sources. One of the simplest and oldest of renewable fuels is the direct combustion of wood. Wood supplied more energy than fossil fuels in the United States until the 1880s, when coal use superseded it.
Unfortunately, the thought of burning wood conjures piles burning in fields with dirty dark smoke and smells that accompany such activities. But the regrowth of forests and improved technology have arrived to change the perceptions of using wood as a fuel.
Advanced Wood Combustion (AWC) may be one of the solutions to supplying heat, cooling and power and reducing greenhouse-gas emissions.
AWC power plants utilize very hot, controlled conditions to ensure that most of the carbon in wood is broken down into energy-rich flammable gasses that are ignited and burn more cleanly than a typical home fireplace or woodstove.
Trees drink in CO2 from the air as they grow and then release about the same amount of CO2 when they're burned in an AWC power plant. Recent test projects show that AWC facilities emit remarkably low quantities of air pollutants, including greenhouse gases, and have thermal efficiencies across the system approaching 90 percent.
Carbon policies need to recognize that wood energy recirculates CO2 already in the biosphere's carbon cycle instead of fossil fuels that add more CO2.
There are many considerations in adopting wood energy policy. North Carolina forests were estimated to be able to sustainably produce 6 to 13 million tons of wood per year. (See C. Hopkins, "Potential of Biomass to Support a Renewable Portfolio Standard in North Carolina.")
(North Carolina State University, Raleigh, USA, 2006, http://bit.ly/R4Roh) Wood energy can increase the value of the forest and support restoration and improvement in the form of timber-stand thinning. Forest bio-energy planning should include detailed inventories and management plans and education for foresters, loggers and the public.
Duke Professor Daniel deB. Richter Jr. recently wrote an article in the Journal of Science in which he used North Carolina as an example for Advanced Wood Combustion.
Richter stated if North Carolina were to install one community scale AWC project (at 75 hp, 0.75 MW thermal) per year in each of the 100 counties over a five-year construction period, that the state could recognize fuel savings of $100 million to $180 million per year and emissions of fossil CO2 could decrease by 0.75 to 1.0 million tons per year.
Ritchter also writes that he thinks that such a program would require approximately 20 percent of an estimate of the state's energy-wood supply. (http://bit.ly/1IZd8l)
Coming back to how UNC-CH can get rid of coal, you can look at a recent story showing how one can refurbish an existing coal plant to use AWC instead. (http://bit.ly/4AO0gj) The Triangle is projected to grow by 1 million people in the next 10 to 15 years. That means that lots of tree-displacing construction must take place. There will be plenty of fuel available to use in a large AWC facility if it were to replace the UNC coal-fired plant.
Now the major barrier to the use of wood as fuel is social, not economic or technical. Our leaders must appreciate AWC for its system reliability, air pollution control, sustainable forest management and how wood energy dollars add jobs and profits to local businesses.
We can start the process of conversion away from coal by making sure that Carolina North is powered and heated by wood and not coal.
Jeremy Todd Browner is an attorney with a solo practice in Chapel Hill.
