Biomass (open-loop and closed-loop)

Using biomass, together with fossil fuels, in our existing fleet is one of the quickest and most efficient ways to reduce carbon intensity. Using renewable biomass, such as chipped wood, to produce electricity helps reduce the net carbon footprint of power production.

In 2009, NRG launched a pilot project at the Big Cajun II plant in New Roads, La., to evaluate local conditions for growing dedicated energy crops near the site (closed-loop biomass). NRG created a test farm on 20 acres of land at the plant site, which is being managed by a local farmer. Harvested into bales like hay, energy grasses are dried and shredded before being fed into the combustion chamber. Since the carbon emitted from the grasses was previously absorbed from the atmosphere during the growing season, combusting the above-ground biomass is nearly carbon neutral. When the extensive root systems of perennial grasses are considered, power from biomass may even be considered carbon negative.

NRG is developing and has fully permitted a project that will convert our Montville plant in Uncasville, Conn., from heavy fuel oil and natural gas to open-loop biomass as feedstock. When compete, the station will use forestry residues, tree trimmings and clean, recycled wood to produce 40 MW of carbon-neutral electric power. The biomass material will be obtained from multiple suppliers within a 100-mile radius of the Montville Station. NRG also is exploring other opportunities to use biomass either incrementally or as sole-source feedstock throughout its fleet of generating stations