Eni-owned clean energy outfit Plenitude has taken a 25% stake in pioneering floating wind technology developer EnerOcean as part of longer-view plans at the Italian utility to have some 15GW renewable plant operating by the end of the decade.

The deal between Plenitude, the value of which was not disclosed, is structured as a “long-term partnership” to support commercialisation of EnerOcean’s W2Power design, an innovative two-turbine concept that has already been tested at part-scale off the Canary Islands.

“Investing in innovative technological solutions is crucial for [us] to support Eni’s energy transition process and to reach [our] 2030 targets,” said Stefano Goberti, CEO of Plenitude, which early this month announced investment in a pair of deepwater wind farms with a total capacity of 750MW off Italy.

“This agreement testifies Plenitude’s willingness to put its skills and offshore engineering resources into unlocking the potential of floating wind power worldwide, which is key to delivering the much needed massive build-out of offshore wind for decarbonisation, supply security and sustainability.”

Pedro Mayorga, CEO of EnerOcean, said Plenitude, which undertook a technology validation of the W2Power design during the investment process, “showed a deep awareness of all core aspects of the technology, and its scrutiny of our work over more than 10 years was meticulous but fair”.

The W2Power concept, which has gone through several incarnations since first being introduced to the market in 2009 as a hybrid offshore wind-wave power design, is engineered to support a pair of “off the shelf” 6MW turbines, giving each unit a 12MW nameplate capacity.

A 40-tonne prototype of the ‘weathervaning’ semisubmersible design fitted with two “generic” 100kW-class turbines was trialled in 2019 off Gran Canaria, with plans for 3-5 unit development of up to 60MW, dubbed CanArray, as the next step for the technology as it moves to market.

“W2Power yields one of the highest power-to-weight ratios and the lowest levelized cost of energy of any floating wind power technology,” said Mayorga.

“This innovative solution integrates patented features and key proprietary technology elements and has successfully completed testing at open sea at prototype level in Spanish waters, being the first multi-turbine solution in the world to reach this level of maturity.”

The W2Power concept is conceived of for a “sweet spot” of water-depths ranging from 35-300 metres.

Floating wind power’s global build-out this decade has been forecast by the Global Wind Energy Council to reach over 16GW, though some analysts remain concerned outdated current government policy frameworks have the potential of limiting the sector to deploying as little as 5GW by 2030.