Aerogenerator

This vertical axis wind turbine is primarily designed for offshore sites and is capable of generating up to three times as much power as a conventional turbine of this scale.

Invented by aeronautical engineer David Sharpe, the Aerogenerator is being developed by Windpower with Billings Jackson as design consultant. An invitation from Grimshaw to include the concept in an international design competition entry gave Windpower and Billings Jackson the opportunity to refine the design to its current iteration: an elegant symbol of sustainable energy generation.

The advantages of vertical axis turbines (VAWT) are multiple. Unlike horizontal axis turbines (HAWT) where the generators and gearboxes are sited inaccessibly at the top making them costly to maintain, VAWTs are ‘bottom heavy’. This has the added advantage of increasing stability. The gears are required to ensure that HAWTs always face the wind while VAWTs can harness the wind from any direction.

In the past, HAWTs have been preferred because they could be built at a larger scale. VAWTs followed the Darrieus wind turbine model, where blades mounted at the top of a tower bow outwards and meet at the top like an egg whisk. Above a certain height, the Darrieus model is destabilised. Sharpe’s Aerogenerator meanwhile has a centre of gravity at the bottom.

The two arms jut out from its base to form a V-shape, with rigid "sails" mounted along their length at intervals. As the wind passes over these they act like aerofoils, generating lift that turns the structure as a whole.

The key contribution Billings Jackson has made to the project is realising a form that could be sited at a harbour entrance for example, rather than hidden away. This enables communities to take pride in the progressively sustainable source of energy by celebrating the technology.