Seagoing Energy Storage Ship Meets The Offshore Wind Transmission Challenge

The Japanese startup PowerX launched in March 2021 with the ambitious idea of ​​reading electricity from offshore wind turbines without having to lay new subsea cables. All you need is a boat with some giant batteries to collect the clean kilowatts and send them back to shore. The devil is in the details, but PowerX aims for its new Power Ark vessel to hit the waves within the next three years.

A boat charge of energy storage for offshore wind farms

Not to be confused with the similarly named Brooklyn-based company with smart home devices that raise money on Kickstarter, the PowerX company in Japan describes the Power Ark as a “power transmission ship” designed to transport electricity from offshore wind farms to virtually anywhere ship can go. .

Aside from potentially reducing the overall cost of building a wind farm, the Power Ark solution will help alleviate growing concerns about the vulnerability of subsea cables to sabotage. Submarine cables have also given rise to environmental problems.

There is no such thing as a free lunch, and maritime traffic also raises safety and environmental issues. But all other things being equal, flexibility in the destination and use of existing port infrastructure is two points in Power Arken’s favor.

Power Ark Energy Storage Ship: See Ma, no subsea cables

PowerX outlined its plans in a press release last August. The company noted in particular the Power Ark concept in the context of Japan’s clean energy goals. According to PowerX, Japan will have to push its offshore wind sector far beyond its existing capacity of 20 megawatts to reach 10 gigawatts in 2030 and up to 34 gigawatts in 2040.

This means several subsea cables together with the wind turbines, which give PowerX a hook to hang the hat on.

“A submarine power cable typically requires expensive construction that comes with significant environmental impacts. By comparison, Power Transfer Vessel stands out as it is resistant to natural disasters, requires less time and development costs, leaves minimal impact on the environment and is therefore capable of to significantly expand the potential for offshore wind power, ”explains PowerX.

Power Ark can also potentially import clean kilowatts from elsewhere in the world to Japan. As the company points out, Japan is already dependent on ships to import almost 85% of its fuel for electricity generation.

Energy storage to sail on the 7 seas

One complication that comes to mind is the amount of time it takes to harvest electricity in megawatts from wind turbines on the high seas. In addition to the technological challenges, labor shortages in the global maritime sector can put a dent in plans, although automation can help solve this problem.

Another challenge is the amount of power needed to power a large ship loaded with batteries. It is apparently the plan to use electricity from the batteries, supplemented with biodiesel for longer voyages.

The biodiesel angle sounds less than optimal in terms of producing the lowest possible CO2 footprint, but it is possible that PowerX may change the plan as new low-carbon maritime technologies emerge.

One option that looks increasingly feasible is to install the latest generation of high-tech sails so wind power can perform some of the heavy lifting. Leading players in the shipping industry have also begun to turn to green ammonia as a carbon-free fuel, although the issue of nitric oxide emissions needs to be addressed.

Either way, if all goes according to plan, the first energy storage vessel in the PowerX series will be a trimaran in prototype scale called the Power ARK 100, a name that reflects its length of just over 100 meters and the goal of equipping it with 100 grid. -scale batteries (a trimaran is a three-hull vessel, a configuration considered virtually unsinkable).

One hundred is also the ship’s capacity in the form of TEU (twenty-foot equivalent unit), which is a unit of measurement based on the dimensions of a standard 20-foot ship container. One hundred TEU is quite small considering that today’s container ships can carry thousands of TEU, but it’s still a pretty big boat.

This could actually happen

In addition to building the boat, PowerX also plans to manufacture its own batteries internally, with assembly in Japan. The company aims to supply its Power Ark ships as well as other applications, including fast charging for electric cars, mains and marine batteries, with a production target of 5 gigawatt-hours per year by 2028.

It’s a pretty high order, but PowerX seems to have its ducks in the water.

On December 3, PowerX announced that it has partnered with leading maritime engineering firm Imabari Shipbuilding Group to develop a prototype Power Ark with a 220 megawatt marine energy storage system on board by the end of 2025, with plans to scale it up after that.

Last week, PowerX also announced that it has recruited the leading classification society DNV for its offshore battery project. DNV will collaborate on technical assessments of both Power Ark and the energy storage system. DNV is known for its work in the field of renewable energy, and PowerX anticipates that it can develop a new class notation for safety validation and other regulatory issues that paves the way for global implementation of the Power Ark model.

Offshore Wind Hearts Energy Storage

PowerX may soon find itself busier than expected. Floating wind turbine technology makes it possible to build wind farms further from the coast and on deeper water, two factors that can complicate the construction of new subsea cables.

Engineers are also developing new ways to squeeze more clean power out of offshore wind farms. In addition to an ongoing series of larger, more powerful offshore wind turbines, some of the latest developments include a doubling of two wind turbines on one offshore platform or the addition of solar panels. The addition of wave energy to wind farms provides another opportunity for growth.

The wave energy field is also being expanded as a stand-alone technology. This could lead to further opportunities for PowerX, especially in protected nature reserves, where resistance to new subsea cables would be difficult, if not impossible, to overcome.

Here in the United States, coastal states have barely begun to exploit the potential to add offshore wind farms to the nation’s energy profile, but major new projects are finally slipping into the pipeline, and the U.S. Department of Energy is already trying to assess the impact on the nation’s transmission infrastructure. Do not be surprised if creative solutions such as ocean-going energy storage also show up here.

Follow me on Twitter @TinaMCasey.

Picture (screenshot): Energy storage vessel for offshore wind farms lent by PowerX.

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