High altitude wind turbines: a step above ground based turbines

I wrote this piece for the Irish Times for April 6th last.  I had been following Makani with interest for some time,  and thought it opportune to write about the opportunities for Ireland.  Then,  by complete co-incidence a week later, the major German power companyy E.on announced a project with the Dutch start-up Ampyx Power for an airborne wind generation system on a test site in Co. Mayo..

The Fianna Fail administration established the Digital Hub in 2003 in Dublin’s Liberties to provide a national focus for innovation, and to nurture digital skills for a new economy. The iconic symbol of the Digital Hub is St Patrick’s Tower, a 40m monolith topped by a St Patrick weather-vane. Built in 1805, St Patrick’s Tower was the largest windmill in Europe for much of the first half of the nineteenth century, when it was used to provide power to Roe’s whiskey distillery, until the distillery converted to coal-fuelled steam power in 1860.

Wind power is now making a comeback. Ireland’s first commercial wind farm became operational in 1992, in Bellacorick in Co. Mayo. Today, there are almost 200 wind farms across Ireland, which together generate nearly 25% of national demand. Nevertheless, our weather volatility currently requires that the base load be met by generation which can be independent of the weather. A combination of peat, coal and especially natural gas are used. In particular, the Corrib gas field is expected to be an underpinning of energy generation for the next 15 to 20 years. There is also a 500 MWatt interconnect with Wales across the Irish Sea through which electricity can be imported from the UK at times of national shortfall, and likewise any surplus generation exported. Ireland also indirectly benefits from an interconnect between Northern Ireland and Scotland.

Brexit presents several threats to our national security, not the least of which is energy security. While interconnection of our national grid and the import of some fossil fuels from UK underwrite our energy generation capacity, the uncertainties of Brexit make it prudent to implement alternatives. The European Investment Bank recently announced interest in financially supporting a 700 MWatt interconnect directly between Ireland and France, which would thus strengthen our ties to the continent and reduce our British dependence.

Imported fuels currently cost Ireland about €15.5M per day, equivalent to about €1,200 per capita per year. Our national security would be strengthened by less dependency on imported fossil fuels, and perhaps ultimately even exporting more electricity than we domestically require, if only we could depend on renewables for the generation of our base load. Can we innovate to overcome the vagaries of the Irish weather and so provide reliable renewable energy? Whilst surface wind is fickle, at higher altitudes wind is considerably stronger and stable compared to surface wind, and especially in Ireland given our oceanic location in the northern hemisphere. There are a number of airborne wind energy prototypes worldwide, although to date no substantial work has yet been undertaken in Ireland. Airborne systems are significantly quieter, and visually unobtrusive, than surface wind turbines because of the altitude at which they fly. There are however as yet no commercial airborne wind energy systems anywhere.

Some prototype airborne systems, such as the Italian Kitegen project, use passive kites. Kitesurfing enthusiasts are aware of the figure of eight path carved into the wind by their kites. Kitegen asserts that a park of about a modest number of computer-controlled large kites, operating at least 500m altitude, could continuously generate the equivalent of a small nuclear power station. The torque produced by the kites on their anchor cables would drive ground based generators. The area above the park would need to be a no-fly zone, but many existing power generation plants are already similarly designated for security reasons.

An alternative approach is to fly the generators rather than keeping them on the ground. Makani – the Hawaiian for ‘wind’ – Power, a subsidiary of X (formally GoogleX), has successfully built a 600 kWatt tethered aircraft-shaped kite. It flies in a horizontal loop at altitude, using brushless generators onboard the kite to generate electricity, passed to the ground through the tether. The kite is computer controlled, and can be automatically landed whenever necessary by winding in the tether. Even larger kites with higher generation capacity are in principle possible, now that the core technology is proven.

The surface wind turbine industry was pioneered by innovative companies, not least Vestas and NEG Micon both in Denmark. Delivering aerodynamically efficient turbines required new and key skills, in design, manufacturing, transportation and installation. Denmark created a new industry for itself from scratch. Commercial airborne wind systems are now another potential inflection point for the renewables industry. They will require the combination of lightweight flight systems and smart electronics, potentially be as large as commercial jet aircraft although very much lighter. They need to be designed not only for safety but also for long operating lifetimes.

Ireland already has a unique geographic position. It also already has a unique economic position, with a combination of multinationals and highly skilled indigenous companies. Could strategic national leadership create a new global industry here, as Denmark successfully did with surface wind turbines? Perhaps St Patricks Tower can be an icon not only of a digital hub, but also of a new wind-based electricity generation industry here in Ireland – and one which also strengthens our energy security.


About chrisjhorn

This entry was posted in Drone, Energy, Ireland, Irish Times, Uncategorized. Bookmark the permalink.

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