AES Hawaii Power Plant


AES Hawaii Power Plant is a medium-size coal-fired electrical power station located in the south-west corner of a Hawaiian island of Oahu. Owned and operated by AES Hawaii, the plant is the only coal-fired power plant in the state of Hawaii, and is the state's leading single source of toxic pollutants. AES Hawaii consists of a single unit on the grounds of Campbell Industrial Park, has a year-around capacity of 180 MWe, and in 2006 represented about 11% of Oahu's commercial electricity supply.
The plant is expected to close by September 2022.

Coal supply

AES Hawaii burns approximately 650,000 tons of subbituminous coal each year. The coal is imported from Indonesia via a marine terminal at the Barbers Point Harbor. From there, coal is taken to the plant by a long conveyor system.

Alternate fuel sources

AES uses alternate fuel sources, such as old tires and used motor oil, to help power the plant. The plant also burns carbon from Board of Water Supply filters. In addition, the ash waste product created by AES is used in concrete mixes. In negotiations between Hawaiian Electric Company and AES in 2014, it was asked that the plant be converted to run partly on biomass.

Environmental impact

AES introduces limestone early into the coal-combustion process, filtering out harmful sulfur dioxide early. Most coal plants use industrial scrubbers to remove harmful pollutants late in the combustion process, which have a higher cost, but are much more efficient, removing as much as 98% of SO2, compared to the 75% removal rate at AES.
According to U.S. Environmental Protection Agency data, the AES plant was the leading source of toxic pollutants in the State of Hawaii, producing in toxic releases in 2013. This represented a pollutant increase for the plant of more than 100% from 2012.

Coal tax break

In July 2015, it was learned that the state approved a special tax exemption for coal that was acknowledged to be for the benefit of AES.