Prospects for global gas-fired generation were emphasized at the ASME International Gas Turbine Institute’s (IGTI) Turbo Expo in Copenhagen recently, despite the surge in renewables. EIA figures show that the most recent waves of generating capacity additions in the US include natural gas-fired units in the 2000s and renewable units, primarily wind, coming online in the late 2000s.
About 530 gigawatts, or 51 percent of all generating capacity, were at least 30 years old at the end of 2010. Most gas-fired capacity is less than 10 years old, while 73 percent of all coal-fired capacity was 30 years or older at the end of 2010. The ‘other’ category includes solar, biomass, and geothermal generators, as well as landfill gas, municipal solid waste, and a variety of small-magnitude fuels such as byproducts from industrial processes (e.g., black liquor, blast furnace gas).
Capacity utilization of natural gas-fired plants has increased year over year. Capacity utilization during peak hours, which was hovering at a little over 40 percent in 2005, increased to over 50 percent in 2010.
Henrik Stiesdal, Chief Technology Officer for Siemens Wind Power Business Unit, who was present at the IGTI Expo, thought gas would become stronger due to the surge in wind. According to his figures, 26 percent of all power for the year came from wind. On a windy night, that rises to 50 percent. When it is extremely windy, it soars to 200 percent (due to exports to Germany).
“Wind provides an extreme environment for the power system,” said Stiesdal. “These high concentrations are effectively changing the definition of base load.” He showed graphs of Danish base load currently. There is already so much wind that base load shifts markedly from one day to the other. According to Stiesdal, by 2020, renewables will become the base load with high variability. “Classical base load stations will disappear and non-renewables will have to have a very high ramping capability. The future belongs to renewables and gas.”
