Japan’s first offshore floating solar array aims to generate power in Tokyo Bay that can then be stored and shipped back to shore in batteries by drone sailing vessels, said a group planning the ambitious project.

Dutch-Norwegian floating PV pioneer SolarDuck said its consortium with Tokyu Land Corporation and Everblue – a Japanese marine specialist – has been selected to build a demonstration plant as part of a Tokyo government plan to mobilise cutting-edge technologies for the city’s next 100 years.

SolarDuck – which is already planning arrays as large as 5MW in the North Sea off Europe – aims by Q1 2024 to deploy an 88kW floating solar system and mooring cables in the Tokyo Bay Area. The energy generated would be stored in batteries that would be transported back to shore by Everblue’s autonomous vessels for use in the power-hungry Japanese capital.

Few further details of the demonstrator such as PV capacity or timescale were given in a statement announcing the contract from the Tokyo government.

The partners said: “Tokyo, a major energy consumption area, is dependent on power transmission from the suburbs. The achievement of energy generation and marine transportation in the Bay Area will contribute to the realisation of a [unique] urban model.”

While deployment of floating PV on inland surfaces such as lakes and reservoirs is already booming, placing solar at sea presents a new level of challenge due to the harsh conditions facing equipment offshore.

China recently claimed a first when it linked two 0.5MW floating PV arrays with a single offshore wind turbine in the seas off Shandong province.