Dan River Steam Station

The Dan River Steam Station in Rockingham County, North Carolina, began life as a coal-fired plant generating 276 MW of energy. Construction began in 1948, and the plant came online in 1949. Built at a cost of $15 million, a third coal-fired unit was added in 1954. Owner Duke Energy installed three natural gas fired single cycle combustion turbines in 1968 to supply an additional 85 MW for periods of peak energy demand.

In 2007 Duke Energy began the process of obtaining approval for additional capacity, this time in the form of the more modern combined cycle natural gas fired process. This additional capacity was sought in anticipation of a growing population and greater per capita future energy demands. The combined cycle power generation process uses the large amount of heat produced by electrical generation to create steam, which is in turn used to drive an additional generator, similar to, but are a lot much larger scale than the turbochargers used on some car engines.

This process is much more efficient, capturing heat that was formerly wasted and turning it into electricity. It is also much more environmentally sustainable, and using natural gas in place of coal produces very significant reductions in the amount of nitrous oxide and sodium dioxide that are released into the atmosphere. The two new gas fired units will produce a little over two times the electricity currently flowing from the Dan River Steam power plant, approximately half the output of a nuclear plant.

Duke energy received approval for the additional generating capacity in 2008, construction was begun in mid-2010, and the new generators are expected to be producing electricity by the end of 2012. Once the new gas turbines are up and running, Duke Energy intends to shut down two of the coal-fired units. It is estimated that the total cost of Duke Energy’s upgrade will exceed $700 million.

Prior to the 1980s, asbestos was commonly used in large amounts as an insulating material in power plants like Dan River Steam Station. The mineral’s excellent heat resistance made it useful to protect against fire hazards and to prevent extreme heat from power generation from harming employees and facilities. Asbestos was used for insulation and machinery, piping and floors. It was also present in boilers, turbines, generators, and seal gaskets for valves, pumps, and piping. Further, it was mixed in with construction cement and also present in floor and ceiling tiles.  Unfortunately, all this asbestos would prove toxic to those who worked around it.