A British company working to produce energy from an advanced design of the traditional kite has released details and footage of its testing as it enters its first round of funding.
Kite Power Solutions told NCE the product had been in development for the last three years and that the list of technical barriers which could prevent the scheme from getting off the ground had now been worked through.
Business development director David Ainsworth said issues such as material life; the control of the kites in wide ranges of wind speeds; whether the energy consumed in the recovery phase of the yo-yo stroke would be significantly less than the energy generated; and whether the system could produce meaningful levels of power had been tested and the project was now ready to be taken to the next stage.
“With more than 100 days of flying with test flights in the last 12 months in wind speeds from 4m/s through to 14m/s plus, and with flights in excess of 3 hours’ duration, we have ensured that all of these issues have been addressed,” said Ainsworth. “We have now provided the team with the confidence to push on the technology development.
“We can’t say that the testing has gone smoothly, we have had our fair share of failures along the way leading to a few kite crashes which have resulted in rapid learning that has improved the technology. With our professional attitude towards health and safety, no one was harmed.”
This video shows the full range of testing which has been completed over the last three years.
Aninsworth said that the next phase was to incorporate all of the lessons the firm had learnt from the last three years to produce a 100KW scale demonstration system to demonstrate the performance and durability of the system and provide the design inputs. It will then be able to move on to the 1MW onshore and 3MW offshore products.
Kite power testing video explained
Single yellow and red kite
“We started flying basic surf kites back in 2012,” said Kite Power Solutions business development director David Ainsworth. “These were flown to validate the control software and the ability to steer and generate power from the kite on a single tether. This also helped with the development of the winch loading system, and the ability to track the kite position in the sky.”
Two yellow and red kites
“These are basic surf kites being flown to show that they can be flown simultaneously and operate in an effective yo-yo energy generation cycle autonomously,” said Ainsworth.
The asymmetric kite
“This is one of our first bespoke kite designs. The kite now has an upper and lower skin so is a full aerofoil which is inflated, the surfkites were not.
“The asymmetric kits is an interesting concept, it is basically a flexible equivalent of a conventional wind turbine blade. The asymmetric kite flies in constant circles rather than the figure of eight flown on the previous surf kites. It will generate more power than a symmetrical kite but has some challenges with low speed handling for docking and launching. The concept will be revisited at a later stage. KPS has patented this solution.”
“This was the first development of active trailing edge flaps to improve steering and low speed performance which helps with docking the system for maintenance, and improved turning when flying figures of eight.”
“A further development of the active trailing edge control system, this one had multiple moving sections. This additional control allows the kite to be pitched at an optimum angle to glide back in the recovery stroke, further reducing the losses in recovery.”
“This is built on the kite 8 concept, with some aerodynamic modifications to improve performance and has roll control, where one side of the kite is pulled by the control pod that can be seen hanging from the kite, which instigates the turn but is then helped by the active trailing edge.”
“This shows a kite with pure roll control in flight. The ability to use pure roll control or roll with trailing edge improves the control options in a wide range of wind speeds.”
This kite shows a significant difference in aspect ratio, i.e. the kite is longer tip to tip and shorter between the trailing edge and leading edge. This is a far higher performance kite that has significant benefits in lighter winds.