Giant wave-riding platform design puts solar power out to sea
Sea-based wind farms are becoming a common sight in many parts of the world, but why not floating solar power stations? Engineers foresee a future where platforms 100 m (330 ft) long and covered with solar panels float on even heavy seas thanks to a new floatation system called Heliofloat.
Still under development, Heliofloat uses flexible, open-bottom floats that are capable of standing up to rough seas that would destroy such a platform sitting on conventional tanks.
Solar energy has a great potential for helping solve the world's energy problems, but among the factors hindering its general application is that suitable land is not always available. Relocating panels offshore could make for installations of incredible size and generating potential, but the seas isn't always a placid place. Even relatively calm areas can suddenly become tempests with waves that can pound a floating platform to kindling in a matter of minutes.
Needless to say, such a potential battering makes sea-based solar plants a very risky investment, but the TU Wien team claims that its Heliofloat system can support lightweight platforms the size of football fields that are stable even in heavy seas – so stable that they can be home to installations of photovoltaic panels or parabolic mirror troughs. It does this by swapping out conventional floats with flexible, open-bottomed cylinders that dampen rather than absorb wave energy.
"The key to this, is that Heliofloat is supported by open floatation devices," says Markus Haider of the Institute for Energy Systems and Thermodynamics. "Were a platform to be simply mounted onto air-filled, closed containers, the design of the construction would have to be inefficiently heavy and robust in order to be able to withstand heavy waves."
In practice, the Heliofloat platform rests on a series of barrels made of a soft, flexible material that are open to the sea at the bottom like the ballast tanks on a submarine. Air is trapped inside the floats and compressed by water pressure to act as a shock absorber. Meanwhile, the sides of the barrel flex as the waves strike them, so they absorb less energy than hard floats. Taken together they are designed to allow the platform to ride out rough seas while remaining stable.
Through an eponymous spinoff company, the TU Wien team is exploring other applications for the Heliofloat technology as it seeks partners and investors. These applications include desalination plants, biomass extraction, protection of lakes form evaporation without interfering with marine life, aquafarming, recreation, and possibly even residential housing.