Middle East solar skyscraper MoU

Australian solar power tower company EnviroMission has signed a breakthrough memorandum of understanding (MoU) with a Middle East developer to build “multiple” installations of its skyscraping technology.

The memorandum with the unnamed developer targets commercialisation of the solar updraft towers through the acquisition of exclusive regional development rights in the Middle East, with a $1.5m lead-off heads of agreement (HoA) to be inked by March.

EnviroMission will also receive a one-off fee, an annual technology fee for each solar tower power station, and equity and board representation on a special-purpose development company capitalised under the HoA.

“This partnership has the potential to redefine the common perception of renewable energy and the way it is delivered — it is the intent to provide base-load, predictable, non- intermittent clean power, in a first for the Middle East,” says chief executive Roger Davey.

“The MoU also represents a significant move towards the global market development of EnviroMission’s solar tower technology to further the commercial reach and potential for [our] shareholders.”

Solar updraft towers generate energy using ultra-tall, turbine-outfitted “chimneys” set into vast greenhouse-like roofs, in a concept pioneered by German consultancy Schlaich Bergermann and Partner more than 30 years ago.

They are made up of three basic components: a vast, open-sided, transparent, circular membrane roof, known as an air collector; a chimney-like tower; and a set of pressure-staged turbines.

As the sun beats down on the air collector, the air and earth beneath the membrane are heated. The air becomes lighter as the temperature rises, and flows towards the central tower, while cooler air is drawn in at the collector's edges.

The collector membrane allows solar radiation through, but absorbs the long-wave "re-radiation" coming off the heated ground, so that heat is transferred to the air flowing inward. When the heated air reaches the tower base, the updraft's air stream is converted into mechanical energy using turbines, and then into electricity via conventional generators.

A 200MW tower, such as EnviroMission is using for projects in the US, would be made up of a “spoked wheel” air collector measuring 3.2km across, topped by a 750-metre-high, 100-metre-wide tower — only slightly shorter than the world's tallest man-made structure, Dubai's 828-metre Burj Khalifa skyscraper.