Wind 32% of New Capacity for 2011
Wind constituted 32 percent of all new generating capacity added to the U.S. electrical grid in 2011. This was actually not as great as the 40%+ figure for 2008 and 2009 but up from 2010. Natural gas made up most of the remainder with coal and other renewables adding only a tiny sliver.
Two trends are illustrated on the graph. The bar chart shows the amount of additional capacity added in each year by source. The line graph illustrates the percentage contributed by wind. The bar chart is calibrated at the left in gigawatts (GW), from zero to 100. The percentage represented by wind is calibrated to the right, from zero to 50 percent.
The bar chart also illustrates added capacity by source. Blue represents natural gas, green is wind, maroon is coal, yellow is other renewables and black is other non-renewables. It is not clear what these other non-renewables are. Not represented are uprates of existing nuclear reactors, which amounted to 1.5 GW in 2008 and .6 GW in 2011.
Remarkably, most new natural gas capacity was added before the rapid decline in gas prices from hydrofracking, which occurred after 2005. This is probably because of slumping electrical demand in recent years and because some of the rise is gas’s contribution has come from running existing plants at higher capacity. Also notable is the amount of coal capacity added in 2010, even though coal is coming under huge pressure from the regulation by the Environmental Protection Agency.
Finally, it must be noted that although these figures show what is called “nameplate capacity” – a genrator's theoretical output – wind farms generally operate at only 30 percent capacity as opposed to 60-90 percent for most other forms of generation. This is because the wind doesn’t always blow. Thus while wind is climbing rapidly in capacity, its overall contribution to the nation’s electrical grid is still only around 4 percent.