Are Diesel Generators Environmentally Friendly?
As the saying goes, necessity is the mother of invention. With their customers facing stricter regulations, generator manufacturers have deployed their ingenuity to craft gensets that are better for the environment, and work better, as well. Here are some of the improvements that have been made:
Cleaner-burning fuel: The latest generators run on a type of diesel called ultra-low sulfur diesel (ULSD), which has been the EPA standard fuel for non-road engines since 2010. As the name implies, the fuel features less sulfur…97% less than standard diesel, in fact. The EPA estimates that NOx emissions will be reduced by 2.6 million tons per year and PM will be reduced by 110,000 tons per year thanks to the use of ULSD in all diesel engines.
Alternative fuel: Recent technological advancements have also led to wider availability of an even greener fuel than ULSD: biodiesel. This progress makes it possible now to take vegetable oil from soybeans or sunflower seeds and use it in conventional diesel engines by modifying the oil itself, instead of the engine, to run in a generator. The result is a renewable energy source that gives off much less pollution than standard diesel, with little to no sulfur.
More efficient combustion: Innovations such as variable injection timing, rail fuel injection, and better configurations of combustion chambers have produced the dual benefits of decreased greenhouse gas emissions, and the ability to put out more power with less fuel. Better fuel economy also means more savings for operators.
Additives: To address the NOx problem, the EPA now requires the use of an additive known as diesel exhaust fluid, or DEF. DEF is used in a selective catalytic reduction (SCR) system, which breaks the NOx down into nitrogen and water in the exhaust system. DEF is incredibly effective, able to reduce NOx emissions by as much as 95%.
Exhaust treatment: Today’s diesel generators also tackle NOx before it hits the atmosphere by utilizing exhaust gas recirculation (EGR). An EGR system feeds oxygen exhaust gas back into the intake, which lowers the combustion temperature and thereby reducing NOx emissions.
Diesel generator technology has grown by leaps and bounds since the days of black smoke billowing out of generator rooms. While there is still progress to be made–EGR systems reduce power and efficiency, for example–generator manufacturers are continually working to deliver products that even the most eco-conscious companies can be proud to own.