Downdraft tower upgrade patent

US downdraft power-tower developer Solar Wind Energy (SWE)has filed a new patent application to protect recent fine-tuning to its design, a skyscraping hollow cylindrical power plant that generates huge energy output from "downbursts" of air.

The company's new 850MW model has a hyperbolic shape that allows for a reduction in the actual wall thickness of the tower so that its shape is made more energy-efficient through increased seismic and wind force resistance. 

Two 685-metre-high SWE towers – which are equipped with a water-spray systems that create high-speed currents out of temperature changes in the air to turn turbines in their foundations – are planned for a maiden development in Arizona, with another pair on the cards for a site in Mexico.

The redesigned tower now has a wider circumference at its base, allowing for additional space for turbines, and a larger integrated water storage reservoir meant to cut energy consumption at start-up.

"This new patent will be an enhancement to the tower patent that has already been issued," states SWE chief executive Ron Pickett. 

"It demonstrates that the ongoing research, development and investigation by the SWE team to refine our model have paid off. Since receiving our initial core patent, which encompasses our unique and efficient power system, our efforts have continued across the board to define a new paradigm for alternative energy, one that is self-sustaining without the need of subsidies."

SWE recently set the seal on weather data modelling that make it possible for the tower's height and diameter to be adjusted along with the amount of water added as fuel to create "a desired amount of energy". 

Under the most recent design specifications, the Arizona towers will have an expected output 600MW an hour, some 18.5% of which will be used to run the plant.

The downdraft tower concept was first hatched in the 1980s by US inventor Phillip Carlson and was subsequently developed by researchers including the Israel Institute of Technology’s Dan Zaslavsky and Rami Guetta.