Minnesota Power, which is trying to convert to one-third renewables and one-third natural gas, found co-firing with wood was one way to move an old power plant partly into the renewable category, the New York Times reports.
Utilities have experimented — with varying levels of success — with sawdust, waste wood from paper mills and logging operations. For instance, Minnesota Power runs a boiler at its Rapids Energy Center on up to 90 percent wood. Other utilities such as Duke Energy and American Electric Power have tried wood with less success.
Adding wood to power plants specifically engineered to burn one kind of coal can be difficult. Other plants such as American Electric Power have had trouble finding enough waste wood to use, the NYT reports.
In September, the EPA proposed Clean Air Act standards that would limit new large gas-fired power plants to 1,000 pounds of carbon dioxide emissions per megawatt hour and new small gas-fired turbines to 1,100 pounds of CO2 per megawatt hour. New coal-fired units would need to meet a limit of 1,100 pounds of CO2 per megawatt hour, and would have the option to meet a somewhat tighter limit if they choose to average emissions over multiple years.
The EPA will issue proposed standards for existing power plants by June 1, 2014.
Meanwhile, carbon pollution from power plants has decreased 10 percent from 2010, according to EPA data released in October.
The greenhouse gas data, which details carbon pollution emissions and trends broken down by industrial sector, greenhouse gas, geographic region and individual facility, show emissions have decreased as more utilities switch from coal to cleaner burning natural gas for electricity generation. The data also shows a slight decrease in electricity production, according to the EPA.