Construction costs for power plants have fallen recently, according to the U.S. Energy Information Administration. Since 2013, the EIA has been collecting data on the construction costs of utility-scale generators. A utility-scale generator has a capacity of more than one megawatt.
“In 2015, wind, natural gas and solar were the most commonly added capacity types, adding 8.1 gigawatts, 6.5 gigawatts and 3.2 gigawatts, respectively,” according to the EIA. “In the case of wind and solar, almost all of these additions (98% and 91%, respectively) were at new plants, as opposed to new generators at existing plants.”
About 60% of new natural gas-fired capacity was new generators at new plants. Though less, new capacity for other fuel types was added at existing plants.
The cost to install wind turbines fell 12% to $1,661 per kilowatt in 2015, from 2013. Larger wind plants, or those producing more than 100 megawatts, had lower average costs than smaller plants, “likely reflecting economies of scale,” according to the EIA.
The cost to install natural gas generators fell 28% to $696 per kilowatt in 2015, from 2013. “Nearly 75% of the natural gas capacity installed in 2015 were combined-cycle units, which had an average installed cost of $614 per kilowatt,” according to the EIA. “Combined-cycle natural gas plants include at least one combustion turbine and one steam turbine and are generally more efficient than plants with combustion turbines alone.” The average cost for plants that only installed combustion turbines was $779 per kilowatt, and the average cost to install internal combustion engines was $1,798 per kilowatt.
The cost to install utility-scale solar photovoltaic generators fell 21% to $2,921 per kilowatt in 2015, from $3,705 per kilowatt in 2013. More than 50% of the solar systems in the United States track the sun and cost slightly more than those installed at fixed angles. In 2015, 73% of the solar systems used crystalline silicon technology, which costs slightly less than those with thin-film panels made with cadmium telluride.