by Michael Gregson
Small scale wind technology is moving ahead – offering scope for more and more renewable electricity to be generated on a distributed basis.
Good news for the planet and investors in renewables: inshore wind power has the potential to supply more than 40 times all the electricity consumed in the world. That’s the conclusion of an international team of scientists led by Professor Michael McElroy at Harvard University.
The Harvard study divides the world into areas of around 3,300 square kilometres, and then identifies regions that are suitable for wind generation. The calculation of the total potential is based on wind speed, air density, the spacing of turbines, and the size of turbine blades.
Very small wind turbines – those with a capacity of under 100kW – comprise the largest part of the small wind market. According to the American Wind Energy Association (AWEA), sales in the US grew by 78% last year, totalling 17.3MW in terms of installed capacity, or 10,500 units, valued at $77 million. Worldwide, the AWEA reports growth of 53%. Global sales of small wind turbines amounted to $156 million, comprised of 19,000 units with installed capacity of 38.7MW.
Much of the US growth was down to private equity investment that allowed manufacturing volumes to increase in the commercial segment of the market (systems of between 21kW and 100kW). However, the residential market (1kW to 10kW) is the largest market segment.
The AWEA’s Small Wind Turbine Global Market Study paints a rosy future despite the recession, with the ever upward trend set to accelerate. It projects a 30-fold growth within as little as five years. Much of this estimated growth will be spurred by the new eight-year 30% federal Investment Tax Credit (ITC), passed by Congress in October 2008 and augmented in February 2009.
This hefty federal tax-sweetener helps put small wind more on a par with solar photovoltaics, which have enjoyed a federal ITC since 2005. It also goes some way to explain why the US commands roughly half the global market and is home to more than a third of manufacturers.
In most markets, including the US, restrictive urban planning regulations and bureaucracy are hampering growth in small wind. In particular, height limitations can reduce a turbine’s productivity and discourage customers and investment.
In the UK the leader of the main opposition Conservative party, David Cameron, installed a rooftop wind generator to display his green credentials. But he faced complaints from neighbours concerned about noise and what they described as an eyesore in a Victorian conservation area. As well as doing little to boost his local popularity, the lack of incentives in the UK also made it a questionable investment decision.
According to newspaper reports, the turbine will take 40 years to recoup its cost in fuel savings. However, despite some recent falls in energy prices, no-one is expecting anything but rises in energy costs in the future, so the manufacturers' 'pay-back' estimate of 15 years might not be so far out after all.
Nottinghamshire-based Eclectic Energy made Mr Cameron’s wind turbine, and director Colin Barden insists they are becoming more cost effective. "There will be huge economies of scale once people start installing these things in large numbers, and the biggest barrier at the moment to that is the planning laws,” he said. "Also, you can sell your unused electricity units back through the grid, and while at the moment it's hardly worth your while doing that with a unit this size, that could change if the Government or the electricity suppliers change the tariff structure.”
VERTICAL TAKE-OFF
Mr Cameron went for a horizontal propeller-shaped wind turbine. But there is a growing debate within small wind about the contrasting merits of horizontal and vertical devices. The German utility RWE, owner of npower, is backing one British vertical turbine maker. RWE Innogy, the venture arm of RWE, led a £7 million investment round in Quiet Revolution last year, contributing £6 million of the total. Other investors in the company include Hazel Capital LLP.
Quiet Revolution, which has a manufacturing facility in Pembroke Dock, South Wales, specialises in small-scale, vertical-axis turbines that are better suited to use in built-up areas than the more conventional horizontal turbines. The company's flagship product, the QR5, a triplehelix- shaped wind turbine capable of producing up to 6kW of power, is five metres high and just over three metres wide.
RWE states that part of its investment rationale is the fact that the Quiet Revolution turbine is – as the company’s name suggests – very quiet and also aesthetic, while at the same time optimising electricity generation from turbulent winds found close to buildings.
Italian company Ropatec, which was established in 2001, is one of the European leaders in vertical axis small wind turbines. Ropatec’s clients include Tesco, B&Q, Audi and the United Nations. The company has introduced the concept of advertising on wind turbines – which it describes as ‘Publienergy’– through the BlueTerra brand.
The Ropatec turbine range includes small turbines designed for off -grid applications (1kW) as well as larger (3kW and 6kW) designs – and the Ropatec ’Big Star Vertical’ which generates 20KvA.
According to the AWEA, improvements in manufacturing techniques needed in the small wind industry may include the use of new composite materials and moulding processes to improve the effi ciency of blades. There is certainly a requirement for the incorporation of more utility-scale turbine technology such as gearboxes. The patented Tricom gearbox is the key to another vertical design, the 5kW Skyrota micro wind turbine, which is being developed in conjunction with Northern Ireland-based Limavady Gear Company. Skyrota’s inventor, Richard Chadwick, was famously rejected by the BBC TV’s Dragons’ Den investors when he pitched for funds in 2006.
Vertical Wind Energy, another Northern Irish company, has also developed a vertical axis solution. The company secured funding of £600,000 from Belfast’s Clarendon Fund Managers and the Viridian Growth Fund last year, for beta testing. Its 3kW turbine has been launched and, according to CEO Tony Gordon, the sales pipeline is already worth £800,000. Vertical Wind expects to have installed around 40 turbines by the end of the year. The company has teamed up with the Mark Group, which specialises in energy efficiency home improvements such as insulation, as its distributor.
According to Mr Gordon, the design of the extruded aluminium blades of the Vertical Wind turbine, which is less complex than the Quiet Revolution helix shape, makes for a scalable manufacturing process. The 3kW turbine uses three blades; Vertical Wind is currently in the process of raising funding to develop a 6kW turbine, which will have five blades and will be longer than the 3kW design.
Elsewhere in the UK, the Evance Iskra R9000 5kW Advanced Wind Turbine, manufactured near Loughborough, is designed to capture more energy at lower wind speeds – another key requirement identifi ed by the AWEA.
On the other side of the Atlantic, Mariah Power is developing a new, enhanced version of its current 1.2kW Windspire vertical axis turbine. By the end of the year CEO Michael Hess aims to produce a 3kW model, capable of powering an entire house.
Mariah Power, which secured a round of Series B funding led by Noventi Ventures in December last year, is working in conjunction with the US Department of Transport on a project to combine its wind turbine with energy-efficient lighting, in order to run street lamps along remote stretches of highway and save the expense of extending transmission lines. Canada’s Vertica Wind Turbines has designed a turbine which is much larger in diameter than others on the market. Its 3 metre and 6 metre diameter models have nominal power of 1.9kW and 7.3kW respectively. The Vertica Wind Turbine can be installed either on the roof of a building or on the ground. According to Jean-Pierre Binda, President of Vertica Wind, the company is working on further developments to the turbines, replacing metal elements with composite materials, reducing the number of components and reducing the weight. The goal is to offer a simple, durable system which can work in urban environments. The low profile and aspect ratio of 2.5/1, coupled with low rpm, minimise noise and vibration.
Meanwhile, over in Australia, Altaus Pty Ltd, which has received funding from Australian investor Cleantech Ventures, has developed a high output vertical axis wind turbine for small to medium scale commercial applications.
Supporters of vertical wind turbines say that, as well as being quieter, they are inherently more suitable for urban environments than their horizontal rivals because they take up less space and – since they are omni-directional – they are more effective at capturing the changeable dirty/turbulent winds typical of built-up areas.
The vertical machines might have their admirers, but they are the new kids on the block when it comes to small wind power and face entrenched competition from the likes of Scotland’s Proven Energy, which boasts a blue chip customer base including BP, Sainsbury's, O2, BT, T-Mobile, Orange and Shell. Proven has projected sales of over £100 million within fi ve years and is recognised as the UK’s leading wind turbine brand.
Figures from the AWEA show that Proven Energy had global sales of 4,800kW last year and made inroads into the key US market, which took 10% of its output. It is a performance that helped to persuade AIM-listed Low Carbon Accelerator to up its stake in the company to 38.9% last December.
Another important UK player is Windsave. The company derives 90% of sales from outside the UK, something founder and CEO David Gordon blames on notoriously strict planning regulations. “Windsave’s order book in the UK amounts to £12 million. But these are tentative orders that are dependent upon receiving planning permission from local authorities,” he said. “We can’t supply the turbines until the customer gets planning. Planning is the bottle neck.”
Although revenues currently stand at £1.1 million, Mr Gordon sees them ramping up to £100 million within three to four years. This ambitious projection is based in part on a new product: a wind turbine mounted on a street lamp, which he believes has a potential market in the UK alone of £1 billion. In contrast to the Mariah Wind project in the US, the Windsave street lamp mounted turbine is designed to feed power back to the grid, taking advantage of the installed infrastructure. 
Windsave’s CEO still owns 55% of the company’s shares. The largest external investor is RAB Capital, which holds 14%. Mr Gordon is fairly relaxed about possible competition from the vertical axis newcomers. He believes there is room for both in the small wind market and that, though vertical sytems might have noise and space advantages, they have their drawbacks too. “In small wind the wind captured with a horizontal blade is greater than some vertical systems. Some vertical systems can’t get the power out of the wind.”
Japanese wind turbine manufacturer, Zephyr Corporation, has come up with an innovative design based on owl feathers that seems to combine some of the the best features of both vertical and horizontal wind turbines. The ‘Airdolphin’, which is Japan’s leading micro wind turbine, uses a ridged ‘silent disruptor blade’ which, like the bird of prey that inspired the design, is very quiet. The Airdolphin also has an innovative rudder design which improves wind ‘captureability’, ensuring that it can generate power in wind conditions as light as 2.5m/second.
The design is already well established in the domestic Japanese market and is widely used on schools and commercial buildings. One interesting use of the Airdolphin is in ‘eco plug-in stations’, where the energy it generates recharges batteries for electric bicycles.
Internationally, Zephyr has made progress in the UK, where McDonalds, Tesco and Travel Lodge are Airdolphin customers. Last year its global ambitions were given a major boost when Investor Growth Capital made a ¥500 million investment, gaining a 21% stake in the company.
Ryosuke Ito, President of Zephyr, said, "This agreement will give a powerful boost to advance our international strategy. The increased investment will enable our company to greatly expand production volumes and will also expand its presence in global markets."
