By: Jesse Broehl
Oil giant Shell has teamed up with Google to commercialize the potentially disruptive technology of high altitude wind energy systems (HAWEs). For around 5 years, Google has supported an energy kite program named Makani under Google’s X Development, Moonshot Factory division, which is focused on bringing to market radical and potentially market disruptive technologies.
Energy kites and other HAWEs come in a variety of applications that mostly involve ascending a sail, kite, wing, or other structure to high altitudes where wind speeds are strong and consistent. Some are simple systems designed, for example, to help tow cargo ships, such as SkySails. Others, like systems from Makani and Kite Power Systems (also with Shell backing), are for producing electricity.
Makani Goes Independent
With Shell’s backing, Makani now becomes a standalone company under Alphabet Inc., Google’s parent company. Shell aims to commercialize the technology on floating offshore wind platforms. Makani has labored under the radar as it has developed its energy kite system. However, the internet is awash in stories gushing over the Shell investment in Makani.
Today’s commercial wind turbines are achieving remarkable heights with hub heights greater than 300 feet. Tip heights for many new turbines exceed 500 feet for onshore and more than 700 feet for some of the largest offshore turbines such as the Vestas V174. The Makani kite is designed to ascend to around 1,000 feet and is tethered by a 1,400-foot-length power transmission cable (more details and a must-see video of its launch at this link).
Anyone with experience flying a kite or kite-surfing gear learns quickly that the most power from the wind is centered in a downwind power window. The Makani kite transitions across the power window in 800-foot-wide loops lasting 10-25 seconds. Small rotors, which resemble propellers, work for both energy capture and propulsion and can generate a theoretical 600 kW peak capacity.
This capacity is comparable to that of the 660 kW Vestas V47 wind turbine introduced in 1996. Today’s nameplate capacities for wind turbines are between 2,000 kW and soon more than 5,000 kW. Offshore units coming to market in the next few years will offer capacities between 10,000 kW and 12,000 kW.
Traditional Wind Turbines versus HAWEs
Traditional wind turbines are much heavier—especially large offshore turbines that require massive costly foundations. The disruptive proposition for Makani is its much lower weight. If it can be deployed on a less costly floating foundation, it could be cost-effective and open deepwater markets where fixed foundations are too costly. This proposition is not impossible but the nameplate capacity will likely need to be more than quadrupled to compete with other floating offshore wind systems under development for large-scale power, such as Statoil’s floating offshore wind efforts.
Meantime, the current 600 kW units could be cost-effective at existing oil & gas (O&G) platforms where onsite energy needs rarely peak 10 MW and any continuous auxiliary power is welcomed. Shell’s next R&D phase is likely to launch Makani prototypes from offshore O&G rigs to provide extra onsite power in remote and deepwater areas where fixed-bottom offshore wind is too costly. Shell and Makani will also work to develop the floating foundations, scale up the kite size, and address electricity losses over the long tether cable.
My take on the Makani announcement is cautious of its commercial viability. However, deep-pocketed backing by Shell’s engineering and offshore expertise is promising. Most big technological advances occur through risk, dogged determination, and by looking far beyond (and above) where everyone else is looking.