Wind energy remains a growth industry worldwide. According to a recent forecast by the Global Wind Energy Council, global installed wind capacity will continue to grow at the rates of the last few years and will have nearly tripled by 2013. China, the United States, and Europe are leading the growth trend. In the past three years, the United States has surpassed Europe to become the world leader in installed wind power. According to the American Wind Energy Association, the US added 8.3 GW of new capacity in 2008, increasing its total capacity to 25 GW, and has added a further 6 GW during 2009 to date.

There are no direct subsidies for renewables in the US system but there is a list of indirect federal and state incentives, mainly tax deductons and exemptions of which the most influential, and considered the most significant factor behind the growth of utility-scale wind energy, is the federal Production Tax Credit (PTC) which applies to large utility-scale wind projects. Currently it is set at 2.1 cents per kWh and is credited against corporate income tax for electricity generated in the first 10 years of a wind turbine’s operation. The Obama administration extended the PTC and investment tax credits (ITC) to 2012 under the American Recovery and Reinvestment Act of February 2009, and added a new incentive, treasury grants taken in lieu of tax credits, designed to promote the growth of renewables despite the economic downturn.

Nonetheless it is a source of continuing irritation to the renewables lobby that the federal government provides substantially larger subsidies to fossil fuels than to renewables. In the 2002-2008 period those subsidies totalled approximately $72 billion, representing a direct cost to taxpayers, while over the same period subsidies for renewable fuels totalled $29 billion. Of course the difference in scale between these two industry areas is immense, but then so is the difference in the aid needed. Now there is a possibility that the Obama administration will alter that balance, but if it does it will not be because the wind industry cannot grow – it has been attracting some of the USA’s biggest investors for several years ­– but because it must grow much faster still to meet president Obama’s climate change ambitions.

German utility E.On has played a significant role in expanding wind power in the US. Its flagship project is located near Roscoe, a small town in west-central Texas, where it has built what is currently the world’s largest wind farm.

After a construction period of a little over two years between 2007 and 2009, 627 wind turbines with an installed capacity of over 780 MW are now operating in Roscoe. The wind farm was built in four phases on four adjacent sites and covers an area of around 400 km², several times the size of Manhattan. The first two of Roscoe’s four phases entered service in September 2008.

Construction schedule

Phase 1 was named after the nearest town, Roscoe, and that name has since been given to the whole development. It was started in 2007, consists of 209 x 1 MW Mitsubishi MWT-1000A units and came on line in 2008. It straddles several counties, and is the cornerstone of the Roscoe complex of E.On projects.

It is situated in a landscape of cotton and wheat fields and income from the project has helped more than 85 farmers continue to plant new crops. This has generally been the case here, that since turbines do not use water, and are sited on land that can command a rent or royalties and still bear crops the 400 or so farmers that occupy the four sites have welcomed its arrival. Wind farms are in fact helping to revive the local economy in remote areas of West Texas and the Texas Panhandle.

Phase II, the Champion site, consists of 55×2.3 MW Siemens Mark II turbines totalling 126.5 MW. These are the largest turbines in the complex, standing 415 feet high from the ground to the top of the blades.The original developer of Champion was Airtricity Inc., then a subsidiary of UK company Airtricity Ltd, the site passing to E.On when it bought Airtricity’s North American holdings in 2007. In March 2008, E.On began commercial operation of the site.

Phase III, known as Pyron, contains 166 x 1.5 MW GE ESS1.5 turbines for a total capacity of 249 MW. Generating the same amount of power using a fossil-fuel based power plant would emit approximately 448 000 tons of carbon dioxide and consume roughly 275 million gallons of fresh water every year.

The fourth and final phase, Inadale, was brought on line in October this year, and consists of 197 Mitsubishi 1MW wind turbines – MWT-1000 models – bringing the total to 781.5 MW, overtaking the nearby 735.5 MW Horse Hollow Wind Energy Centre on its way to becoming the world’s largest wind complex.

‘The completion of Roscoe is a major success for our team and another milestone in the development of renewables in our power generation portfolio. In just under two years we have increased our wind park capacities worldwide to 2600 MW, with over half of that total, 1500 MW, in the United States’ said Frank Mastiaux, CEO of E.On Climate & Renewables. ‘With large-scale projects like Roscoe we are helping renewables to achieve a faster breakthrough in economic and technological terms. For this purpose we will invest r8 billion worldwide up to 2011. Our aim is to reach a capacity of 10 000 MW in 2015. North America is one of the most attractive markets for renewables worldwide, especially for onshore wind plants.’

Everything is bigger in Texas

Wind power in Texas as at April 2009 consisted of over 40 wind farms and with a total installed rated capacity of 7907 MW Texas produces the most wind power of any US state, followed by Iowa with 2883 MW. Wind energy accounts for 3.3% of all the electricity used in the state, is growing, and is also a valuable export.

Several forces are working to the advantage of wind power in Texas. The wind resource in many areas of the state is very great, large projects are relatively easy to site, and the market price for electricity is relatively high. The wind power industry is also creating many jobs and farmers can earn extra income by leasing their land to wind developers.

As well as Roscoe other large wind farms in Texas include: Horse Hollow Wind Energy Centre, Sherbino Wind Farm, Capricorn Ridge Wind Farm, Sweetwater Wind Farm, Buffalo Gap Wind Farm, King Mountain Wind Farm, Desert Sky Wind Farm, Wildorado Wind Ranch, and the Brazos Wind Farm.

E.On wind in the USA

Four of E.On’s five operating US wind farms are in Texas, taking advantage of some of the best wind conditions in the world. Another factor is the USA’s attractive investment climate for renewables. 35 states have committed themselves to expanding their renewables capacity, and the Obama administration is expected to initiate long-term contracts as well as new legislation. The Obama ‘New Energy for America’ plan calls for renewables to account for 10 % of the country’s generating capacity by 2012 and 25 % by 2025. The United States will therefore remain E.On’s single biggest renewables market. It currently has a pipeline of wind-power projects in the US with a total capacity of 6 GW.

E.On Climate & Renewables currently operates four other wind farms in the United States, three of them in Texas (Table 2) , with an installed capacity of 391 MW, and is constructing two others, Stony Creek in Pennsylvania and Papalote Creek in southern Texas.

Under construction

The 52.5 MW Stony Creek facility is E.On’s first project in the PJM market in Pennsylvania. The array will consist of General Electric 1.5 MW 1.5 ESS units which are being erected on a reclaimed surface (open cast) coal mine.

Rising from the cotton and grain farmland of San Patricio County, Papalote Creek 180 MW Wind Farm is E.On’s first south Texas project as well as its first US project using Vestas wind turbines, in fact 109×1.65 MW V82 turbines. Over 80 local landowners are said to have supported the project, whih when operational will avoiding the emission of more then 324 000 tons of carbon dioxide and save a quarter of a billion gallons of fresh water every year compared to a conventional steam-driven fossil fuel plant.