In the long-term, disruptive technology such as airborne offshore wind energy systems could play a growing role in the offshore wind industry, a leading consultant told the OWJ conference in London.
Addressing delegates about key trends in the sector, now and in the future, Mike Blanch, an associate director at BVG Associates who has more than three decades of experience in wind energy, said he believed airborne offshore wind energy systems were a potentially disruptive technology that could have a major role as the offshore wind energy industry continues to evolve.
Citing a number of potential technologies that could play a role in the long-term – including multirotor offshore platforms and new types of ‘float and submerge’ foundations among others – Mr Blanch noted that Kite Power Systems (KPS) in the UK had recently secured consent to test a 500 kW airborne system.
KPS has developed an airborne solution to harness wind energy that could be game-changing, said Mr Blanch. Accessing greater wind resources, kites offer the prospect of a much lower cost of energy than the next generation of conventional horizontal axis wind turbines, he said. KPS asked BVG Associates to provide an independent assessment of cost of energy and energy production of its twin-kite airborne system.
BVG Associates assessed capex and opex for a 500 kW scale system, then extrapolated to a first 3 MW system and for volume production. It also produced an independent model to calculate the power curve and annual energy production for the KPS system. It compared the levelised cost of energy (LCOE) for a 500 MW windfarm using KPS kite turbines with that for a windfarm using conventional horizontal axis wind turbines. It also assessed the LCOE for a project using KPS technology to repower a windfarm at the end of its design life and provided a sensitivity analysis considering some of the technical design options available to KPS.
BVG Associates estimated that once commercial, the LCOE from a windfarm with KPS technology would be 26-47% lower than conventional technology, depending on windfarm location, choice of foundation and kite size. KPS subsequently secured additional funding from the UK government to develop a prototype.
More recently, KPS secured permission from Dumfries & Galloway Council to test a 500 kW kite at West Freugh in Stranraer. The proposal seeks the change of use of part of the existing artillery range for the research and development of the kite powered wind energy system.
KPS’ power system features two kites which fly up to an altitude of 457 m. Both kites are attached by tethers to a winch system which drives a generator as they spool out, thus producing electricity for the grid.
The company believes the technology has the potential to transform the global onshore and offshore wind generation markets, believing it is cheaper to manufacture and requires less construction and installation materials than conventional wind turbines. A 40 kW system has already been tested at West Freugh and the 500 kW demonstration model is being manufactured and assembled in Dumfries.