First Wind's plans to launch its $US300 million IPO this week – 12 million shares at between $US24 and $US26 – have been stirring up a bit of speculation over whether the Boston-based wind power company has got what it takes. Owned mostly by private equity firm Madison Dearborn and hedge fund operator DE Shaw, First Wind funds, develops and operates utility-scale wind energy projects in north-eastern and western US and Hawaii. It had $US75 million in sales in the last year and, with seven projects amounting to 504 megawatts of capacity now in operation, it expects to have capacity for another 268 megawatts in operation or under construction by year-end – and 1900MW by 2014, says Reuters.

So why the concern? According to Iris Kuo at GreenBeat, there are a few reasons why things don't look entirely promising for First Wind. For starters, she says, "recent cleantech IPOs like smart meter company Elster and biofuel company Amyris all debuted below planned ranges." And then there's the fact that First Wind, "which has lost $US233 million and has $US582.2 million in debt... says it does not have enough cash to cover that loss and is at default risk." Of the money it hopes to raise in the float, $98 million will go towards debt service, and $78 million will go to retire a loan that has a 17 per cent annual interest rate and matures in March 2013. And then theres the fact that a a key wind production tax credit expires at the end of this year, says Kuo, "and the American Wind Energy Association warns that the future of the wind industry depends on the measure’s renewal." According to Reuters, new US wind installations were down 71 per cent in the first six months of 2010.

Furthermore, low electricity prices are making it more difficult to get the contracts needed to secure private financing to build wind farms in the US, says Reuters. "Private financing for wind projects often comes in the form of power purchase agreements, or PPAs, which last between five and 20 years and whose value is calculated based in part on electricity prices." But one factor driving utilities to sign PPAs with wind and solar developers has been the adoption of standards by some US states – including Massachusetts – requiring electricity suppliers generate a certain percentage of their energy from renewable resources. 

Tower of strength

Melbourne-based solar group EnviroMission announced yesterday that the Power Purchase Agreement with the Southern California Public Power Authority (SCPPA) to purchase green power from the first proposed EnviroMission Arizona Solar Tower power station had been approved at the SCPPA board meeting last week. This is welcome news for the company that bills itself as the sole developer and promoter of Solar Tower technology in Australia (actually, it says it owns the global license to Solar Tower technology, "excluding China".) Since listing on the ASX in August 2001, it hasn't exactly lit up the market – although the company's share price experienced a 67 per cent gain in anticipation of the PPA news last Friday.

EnviroMission's Solar Tower technology uses the sun's radiation to heat a large body of air under an expansive collector zone, which then rises as a hot wind through large turbines in a 'solar chimney' structure to generate electricity. According to EnviroMission's website, a Solar Tower power station would create the conditions to cause hot wind to flow continuously through 32 x 6.25MW pressure staged turbines to generate electricity. It says the technology has been tested and proven with a successful small-scale pilot plant in Manzanares Spain – a collaborative effort between the Spanish government and the German designers, Schlaich Bergermann and Partner. According to EnviroMission's website, the test plant operated for seven years between 1982 and 1989, and consistently generated 50kW output.

Solar Tower energy generation doesn't require the use of water, which puts it at a distinct advantage to other renewable and traditional coal & nuclear energy producers. "The Solar Tower project earmarked for Arizona will abate the approximate usage of 528 million gallons of potable water (drinking water) per annum," says the company. The facility is also expected to offset more than one million tonnes of greenhouse gases annually. Roger Davey, EnviroMission CEO, called the finalisation of the PPA "an important milestone that will allow finance to be secured and Front End Engineering and Design (FEED) that is required to break ground at the site earmarked in Arizona."

Pretty clever

And speaking of difficulties facing wind power companies, one of the bigger among them is that the wind doesn't always blow. Wind is an intermittent power source, leaving utilities and wind companies with the task of figuring out how to harness that energy for use.  Which brings us to the team behind the “Windstalk concept,” which was presented at the 2010 Land Art Generator Initiative (LAGI) competition in Dubai – and won a second place mention from the jury. (LAGI is a project that aims to inspire the design and construction of a series of public art installations that combine aesthetics with clean energy generation.)

The “Windstalk concept” – by New York-based Atelier DNA, designed for Masdar city, the clean technology cluster in Abu Dhabi – consists of 1203 stalks made of carbon fiber reinforced resin poles that generate kinetic energy when moved by the wind, says Marta Iglesias on CleanTechies. "Each stalk is anchored to the ground using concrete bases that contain a chamber with a generator. A series of piezoelectric ceramic discs surrounded by electrodes are located in each hollow pole, and cables connect even and odd electrodes separately. When wind blows, the movement generated in the poles forces the compression of the ceramic discs, hence generating a current through the electrodes. The generator placed at the base of each pole converts the kinetic energy into electricity."

“Our project takes clues from the way the wind caresses a field of wheat, or reeds in a marsh; our hair on a gusty afternoon," explains Atelier DNA. And to address the wind-doesn't-always-blow problem, the team has designed two chambers located under the poles that store the energy produced. When wind stops blowing, water flows down from the upper chamber into the lower chamber, turning a series of pumps into generators. The owners of the concept estimate overall output of the Windstalk project would be the same as a wind turbine array. And for the artistic touch, there are LED lights at the top of every 55 metre high pole that glow and dim depending on wind strength.