Experimental wind-power developer Makani—owned by Google parent company Alphabet — is to bring its energy kites to offshore environments, following successful trials of the technology at a test site in Hawaii.

After five years of development at Google’s X Moonshot factory in California and more than a decade of development in total, Makani (www.makanipower.com) is now an independent Alphabet company and is partnering with Royal Dutch Shell to expand offshore, according to its CEO, Fort Felker.

Hundreds of millions of people live within 25 miles of a coastline where the wind is strong and steady, but two thirds of coastal waters around the world are too deep for today’s wind-energy technology; this is where Makani fits in.

Its kites are tethered to a turbine and can efficiently harness energy from the wind 1,000ft above the ground.

Unlike most floating offshore wind technologies deployed in water more than 50m deep, Makani’s kites do not need to be supported by large platforms.

The plan is to mount them on small spar buoys moored with a synthetic line and a gravity anchor.

Mr Felker said: “This is possible because Makani’s kites are 90% lighter than turbines of a similar power rating, and the overall system is smaller, replacing tonnes of steel with lightweight electronics and smart software.

“We plan to kick off testing of this new floating offshore system with demonstrations in Norway later this year, and we are developing additional partnerships.”