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Japanese Company Plans to Use Battery-Powered Ships to Transfer Power

image credit: PowerX
Julian Jackson's picture
Staff Writer, Energy Central BrightGreen PR

Julian Jackson is a writer whose interests encompass business and technology, cryptocurrencies, energy and the environment, as well as photography and film. His portfolio is here:...

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  • Aug 18, 2021

In a innovative scheme proposed to sidestep transmission cables from offshore wind, Japanese company PowerX has come up with a “Power Transfer Vessel” to carry electricity from offshore wind farms to shore and also intends to build a large-scale battery factory in Japan to produce EV fast-charging, grid storage and marine batteries.

The Challenge

The Japanese government has issued targets for renewable energy to generate 36-38 per cent of the country's power production in FY 2030, a major hike from its previous goal of 22-24 per cent. This will need an increase in offshore wind generation capacity from the current 20MW up to 10GW by 2030 and then a further boost to 30-45GW by around 2040. Japan is unfortunately surrounded by deep coastal waters, which limit the potential sites for setting up offshore wind farms. The PowerX company was founded with a conception to change how the world consumes and transfers renewable energy by providing a unique solution that would remove the restriction on where to locate power generation facilities, which will allow a greater flexibility for offshore wind farm siting, especially for an island country like Japan. By pushing forward innovation in the way the world stores and transports energy, PowerX aims to enable an unprecedented energy transmission between any two ports on the planet, and thus accelerate the adoption of renewable energy globally.

The Proposed Solution

PowerX will design and build an automated Power Transfer Vessel called “Project Ark”, with a massive battery payload that is integrated with the ship's controls to transport offshore wind power to shore. An undersea power cable normally requires construction that is both expensive and often has substantial environmental impacts. In contrast, the Power Transfer Vessel's rationale is that it will be resilient to natural disasters, requires less time and cost for development, has a minimal impact on the environment, and therefore will be a positive factor in the expansion of offshore wind power developments.

Most of the world's energy is transported by ships, in the form of oil, gas, and coal. Japan's power is 84.9 per cent generated by burning carbon-based fuels imported by such maritime transportation. As the world transitions away from fossil fuels, the “energy ship” of the future will carry electricity from clean and renewable sources, replacing the fuel-carrying diesel-engined vessels of today.

The Design

Project Ark - Power Transfer Vessels


Image: PowerX

The prototype model of the Power Ark series, "Power Ark 100" is a 100TEU trimaran specially designed for transferring renewable energy in Japan's coastal waters. TEU means Twenty-foot Equivalent Unit, the standard storage container, and is the normal method of measuring ship cargo capacity. Upon its completion in 2025, Power Ark 100 will carry 100 grid batteries, delivering 200MWh of power - equivalent to the daily electricity consumption of 22,000 Japanese households. The vessel's range is designed to be up to 300km when running only on electricity, and it will be able to perform long-distance, intercontinental clean power transmission when it is running on by both electricity and sustainable biodiesel fuels – that is a hybrid power ship.

New Factory Construction to Produce the Necessary Batteries

To realize this vision, PowerX will also be building a giga-scale battery assembly factory in Japan to mass-produce batteries for the Power Transfer Vessels. With the transition toward decarbonization across the globe, the demand for large-scale energy storage is escalating. The factory will manufacture battery cells which will be produced based on the new markets opening up, which will include EV fast-charging, grid storage, and marine batteries. The factory's annual production capacity is planned to be 1GWh by 2024, and will eventually reach 5GWh by 2028. Production lines will be automated to mass-produce at a low cost per unit.

This is an ambitious project, which may well mean that in future offshore wind farms will recharge ships at sea, instead of transmitting their power via cables to the nearest land.

Matt Chester's picture
Matt Chester on Aug 18, 2021

First reaction: that sounds inefficient..

Second reaction: I guess that shows how much being able to generate offshore renewable energy  is valuable to Japan

Pulikkal Ashokan's picture
Pulikkal Ashokan on Aug 19, 2021

PowerX's Power Transfer Vessel - I felt it is a well-positive adventurous activity. Why I comment positively is due to my experience to find out new methods to generate clean energy for 20 years. But initially it looks the volume level shall be less to carry electricity from offshore wind farms to shore. Because i had designed a mini-hydro power unit to produce electricity within the ships itself. Compared to this method, I felt, powerX work shall be costly and with limited power generation.
Of course insertion of new technics to the existing after a period of time, in future, will make this project more profitable. I have now invented 3 major methods to generate clean energy, which, i am optimistic, will help the world not to look for new methods for another 500 years. Being an inventor, I will support all the new and innovative proposals. But it will take time.
ashokan, researcher-inventor:

Dr. Amal Khashab's picture
Dr. Amal Khashab on Aug 22, 2021

Hi Matt

I have another point of view about the inefficiency: actually, the NaS battery storage ( 2MWh Japanese manufacturing) has a very high efficiency near 89%, while transmission line efficiency reaches 95%. Putting in mind the saving investment cost of transmission line erection (huge lump sum). This will result in lower LCOE in the case of Power X Project.

Matt Chester's picture
Matt Chester on Aug 23, 2021

Great points, Dr. Khashab. I agree with you-- I was just noting that before looking at numbers my 'gut' reaction was to be surprised that such a plan could make sense in terms of costs and efficiencies, but you're right that when you actually dig into it that it makes more sense than my uninformed 'gut'!

Ashish  Sharma's picture
Ashish Sharma on Aug 24, 2021

That sounds uneconomical but possibly the only technically feasible solution

Julian Jackson's picture
Thank Julian for the Post!
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