Japanese startup building ship with 220MWh battery storage to bring offshore renewable power home

December 7, 2021
LinkedIn
Twitter
Reddit
Facebook
Email
Rendering of the PowerX Power ARK, a ‘power transfer vessel’. Image: PowerX.

Development has begun in Japan of a marine battery storage vessel that would be charged at sea from offshore wind and then carry the power back to land.

Startup PowerX has come up with the concept of the Power ARK, a so-called ‘power transfer vessel’. The company said last week that it has formed a partnership with shipbuilding company Imabari Shipbuilding to develop a prototype by the end of 2025. 

The idea is to replace the fuel-carrying ships of today which import fossil fuels to Japan and elsewhere and facilitating the uptake of renewable energy. According to 2019 statistics from Japan’s Agency for Natural Resources and Energy, almost 85% of the country’s power was generated from carbon-based fuels imported by sea.

The futuristic Power ARK electric container ship will host 220MWh of nameplate battery capacity with the vessel itself powered by a combination of electricity and biodiesel. 

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

The collaboration with Imabari Shipbuilding, one of Japan’s two largest shipbuilding companies, became effective on 2 December. Described as a capital and business alliance agreement, Imabari has invested ¥1 billion (US$8.86 million) into PowerX.

The pair will build the prototype together with any necessary third-parties. The startup will manufacture the battery storage system and battery-related systems. 

PowerX was incorporated earlier this year under the leadership of tech entrepreneur Masahiro Ito and counts Northvolt co-founder and COO Paolo Cerruti among its external directors. 

The company also intends to build its own automated gigafactory to assemble batteries in Japan from outsourced battery cells. Annual production capacity of 1GWh is being targeted by 2024, for ramping up to 5GWh by 2028. Battery systems produced there will serve the marine, EV fast charge and grid-scale storage markets. 

“The realisation of a decarbonised society is a major issue that the shipbuilding and shipping industries must tackle,” Imabari Shipbuilding’s president Yukito Higaki said. 

“We see this alliance as an excellent opportunity for Imabari Shipbuilding to invest in as well as partner up with PowerX, who is taking on the challenge with a different approach from the existing shipbuilding and shipping industries.” 

“Through this alliance, we aim to jointly develop and introduce “Power ARK” to the world as a “MADE in JAPAN” product with Imabari Shipbulding,” PowerX CEO and representative director Masahiro Ito said. 

Read Next

Premium
December 24, 2025
“A multi-stream revenue stacking model” made it possible for Pacifico Energy to self-fund a new grid-scale battery storage project in Japan.
December 17, 2025
Thermal energy storage can make steam for chemical industries and manufacturing economically viable, writes Martin Schichtel, CEO and Founder of Kraftblock.
December 12, 2025
Utility Origin Energy has hired Wärtsilä to expand its battery storage installation at the Eraring coal power plant site in New South Wales, Australia.
December 11, 2025
A trio of large-scale BESS announcements by major power firms of 700-800MWh capacity each in Germany show the country’s energy storage market moving into the new era of scale.
December 9, 2025
European energy independence is achievable if long-duration energy storage is factored into the mix, writes Oonagh O’Grady of Hydrostor.