The bulk of the new 2012 installations happened on Q4. This amounted total of 8380 MW new wind power. This would imply that the capacity factor in 2012 was near 0.3 what is usually rounded up into ⅓.
Official: US Wind Power Accounted For 42% Of New Power Capacity In 2012, Beat Natural Gas http://cleantechnica.com/2013/01/31/us-wind-power/ Wind power is indeed coming in a gust, and and new wind is already cheaper than new coal power. The price of wind electricity in US is something between $50 to $80 per MWh what is quite competitive. There is still however a problem that when there are high winds, market price for electricity tend to be low due to high output of wind farms. Therefore small tariff would be good idea still to maintain. That decreases the risk of installing new windmills and thus accelerates the installation of new wind farms. There is however interesting to see that battery technology is evolving rapidly and the price point of batteries is nearly competitive. GE just introduced new smart windmills that has also a grid level battery installed, they will to be installed in Netherlands later this year. Rapidly evolving battery technology is also good news for electric cars and EVs could operate as great storage for fluctuating wind power output. Tesla will introduce on later this year new 120 kWh version of Model S. On daily driving usually 20 kWh is enough, therefore additional 100 kWh could be charged only during high winds or when full charge is needed. Also advanced blade materials are great. And carbon fibers could cut down the cost of windmills quite significantly, perhaps 30 %. Also ultra strong and ultra light graphene is coming and this could cut down the price even further. We already have tennis rackets that are reinforced with graphene! —Jouni On Feb 2, 2013, at 12:58 AM, Jed Rothwell <jedrothw...@gmail.com> wrote: > This is a little complicated. Honestly, too complicated for a spreadsheet or > for my limited mathematical abilities. > > We have a moving target and two sets of numbers, one ending in December and > the other in November. There are reportedly ~60,000 MW of wind turbines in > the U.S. as of the end of 2012. > > Would someone care to estimate the actual capacity factor of these turbines? > I would like to know approximately how much energy these turbines produced. > Actual performance is usually estimated at 1/3 the nameplate capacity. In > other words, 60,000 MW of turbines should produce 20,000 MW on average, which > over 1 year adds up to 174,720 GWH (or "thousand megawatt hours" -- the EIA's > preferred units). > > The number of wind turbines increases in spurts throughout the year as new > turbines are installed and new wind farms are put on line. These MW quotes > are for total number of installed turbines. Total power increases, though > some old turbines are removed or upgraded. Output energy also increases. As > follows: > > Year (start of year; January), total capacity MW, increase MW over previous > year, energy from previous year in GWH (1000 MWH) > > 2013, 60,000 MW, 13,124 MW, 125,914 GWH > 2012, 47,000 MW, 6,800 MW, 109,521 GWH > 2011, 40,200 MW . . . > > In other words, in 2012, energy increased by 16,393 GWH. That was coming from > more turbines than there were in 2011, but how many more? The numbers > increased continuously, by a total of 19,924, but a turbine installed in > October 2012 contributed practically nothing to the 2012 totals. > > You could say that the 60,000 MW of turbines should have produced 174,720 GWH > in 2012, but they only produced 125,914 so the capacity is lower than > claimed. But that is not true, because most of the 13,124 MW added that year > was not there at the beginning. Would it be reasonable to say the average > capacity in 2012 was halfway between 47,000 MW and 60,000 MW? 53,500 MW > nameplate, or 17,833 MW with the fudge factor of 1/3? > > That would produce 155,789 GWH which is still considerably above the actual > total of 125,914. Using that crude method of assuming the average was 53,500 > nameplate, the capacity would be 27%, not 33%. > > - Jed
