Makani tests energy kite
By:
Tom Russell
15/08/2019
Makani
Makani has conducted an
autonomous test flight of its energy kite in the North Sea off Norway.
The California-based company is developing energy kites that use a wing
tethered to a ground station to generate energy from the wind. As the kite
flies autonomously in loops, rotors on the wing spin as the wind moves
through them, generating electricity that is sent down the tether to the
grid.
Makani was founded
in 2006 and received funding as part of Google.org's Renewable Energy
cheaper than Coal initiative. In 2013, Makani Power was acquired by Google and
was folded into Google X. In February 2019, Makani was separated from
X and made into a subsidiary of Alphabet, the parent company of Google.
At the same time, energy giant Royal Dutch Shell made a minority
investment in Makani and began a partnership with the company to develop
its business.
For its recent demonstration at METCENTRE in Norway, the company transported
its airframe on a flatbed trailer, using a mobile boom crane to lift the
kite onto its perch, and using two coastal tug boats it installed the kite
and spar offshore at a water depth of 220m.
Makani completed two flights from the floating platform. The first quick
flight included launch, hover away from the perch, and an autonomous landing.
The second, longer-duration test, demonstrated crosswind flight. Makani
stated that the kite flew according to commands from the flight controller,
and affirming that its motion and that of the floating platform matched
its pre-test simulations. In preparation for landing, the kite transitioned
out of crosswind into a stable hover. However, it did not successfully
land on the platform, and the flight ended with the loss of the energy
kite. Makani outlined that the offshore flights provided new information
that the team analysing and applying to making system improvements.
Makani’s claims that its transition offshore introduces new technology
that once commercialised can access stranded wind resources at sea. The
low mass of the kite and correspondingly-low materials and installation
costs make it possible for Makani’s airborne wind power system to take
advantage of existing infrastructure and supply chains. The company stated
that this means energy kites can be deployed from small and medium-sized
ports without the need for specialised vessels or massive cranes.
Next steps include additional flights onshore in Hawai’i and offshore
in Norway with a focus on flying in a range of environmental conditions,
improving landings at sea, and refining remote operations. The company
will work with Shell to optimise its floating platform and mooring system,
minimising the need for personnel to access the kite at sea before or after
flight, and connecting to the grid.
