Japanese startup plans to build a 220MWh battery-storage ship to bring back offshore renewable energy

Japan has begun developing a battery-storage vessel that will use offshore wind to charge at sea and then bring the power back to land.

Startup PowerX has come up with the concept of Power ARK, the so-called "Power Ark." The company said last week that it had entered into a partnership with shipbuilder Imabari Shipbuilding to develop a prototype by the end of 2025.

The idea is to replace today's fuel carriers that import fossil fuels to Japan and elsewhere, and to boost the uptake of renewable energy. Nearly 85 percent of the country's electricity comes from carbon-based fuels imported from sea, according to 2019 statistics from Japan's Agency for Natural Resources and Energy.

According to the Japan Maritime News Network, the offshore wind power containerized power carrier is mainly used for the power transportation of offshore wind power generation, and the cost will reach several billion yen. In general, offshore wind power generation is transported by submarine cables, but the construction cost of laying submarine cables is about 100 million to 200 million yen per kilometer, and the use of containerized power carriers is expected to significantly reduce transportation costs.

It is understood that in August this year, Japanese e-commerce company ZOZO announced the official establishment of PowerX, which is committed to building the world's first offshore wind power containerized power carrier. "Power ARK 100" can carry 100 grid batteries, or 200MWh of electricity, which is equivalent to the total power consumption of 22,000 Japanese households in one day. If electricity and sustainable biofuels are used at the same time, this type of ship can achieve electric transportation for 1,000 to 3,000 kilometers. Design and construction of the "Power ARK 100" is expected to begin in January next year, with delivery due in 2025.

According to ZOZO, this type of vessel will become an entirely new method of energy storage and transportation, enabling unprecedented energy transmission between any two ports, thereby accelerating the application of renewable energy. In addition, PowerX is also considering how to use ordinary containers for electric transportation.

PowerX also intends to build its own automated gigafactory to assemble batteries in Japan using outsourced cells. The annual capacity target is 1GWh by 2024, increasing to 5GWh by 2028. The battery systems produced there will serve the marine, electric vehicle fast charging and grid-scale energy storage markets.