Storing energy on the seabed

Deep PurpleKongsberg/Lysaker

With support from Innovation Norway, Deep Purple is developing technology that makes it possible to store surplus energy from wind power.

If Norway is to maintain its role as an energy supplier to Europe and at the same time achieve our climate targets, we must, in a relatively short period of time, transition from oil and gas exports to the sale of clean energy such as electricity and hydrogen.

Deep Purple is a subsidiary of TechnipFMC, which is currently a global provider of infrastructure and services within the fields of gas, oil and energy. They are now working on a large-scale and sustainable pilot project that focuses on storing wind power in the form of green hydrogen. The pilot project has been named Deep Purple and is carried out in collaboration with a number of other companies, including Vattenfall Vindkraft, Repsol Norway, Nel Hydrogen Electrolyser, Umoe Advanced Composites, Slåttland, ABB, DNV and Sintef. In addition, the University of South-Eastern Norway, Energy Valley, Ocean Hyway Cluster and GCE Ocean Technologies are important partners. The pilot is due to be ready as early as next year, in 2022.

“Together, we have a lot of core knowledge about system integration, automation, product development, safety and risk management that is valuable in a new technological arena” says Terje Andre Løver, project manager for Deep Purple.

In order to make maximum use of wind power that is produced, we must both store and extract the energy in a technically and economically optimal manner.
Terje Andre Løver, Deep Purple.

Storage challenges

The purpose of the pilot project is to achieve and document good functionality of a completely new energy system, which makes it possible to store large amounts of surplus energy from wind power.

“One of the main challenges when producing electricity from clean energy sources, such as wind, is that resources are unstable and variable”, Løver explains.

“In order to make maximum use of wind power that is produced, we must both store and extract the energy in a technically and economically optimal manner”, he says.

This is the exact problem that Deep Purple aims to solve.

More powerful than the largest battery banks

In the project, the energy produced by the wind farms is emulated to understand how the variable power affects the energy system that will make renewable hydrogen. Firstly, seawater must be desalinated and then undergo water electrolysis, so that hydrogen and oxygen are separated. The surplus energy from wind power is thus converted into hydrogen, which is then stored in large tanks.

In periods when energy production from the wind farms is not large enough, the stored hydrogen can be converted back into electricity. This will balance out end users’ need for consistent power. Since hydrogen is an environmentally friendly energy carrier, it produces no emissions other than clean water, oxygen and salt.

“Because of the way we can store electricity, the technology in the Deep Purple project could be compared to a huge industrial battery”, says Løver.

However, the storage capacity will be much more powerful than the battery technology we know today. In comparison, the world’s largest battery parks have a capacity of around 700 Mwh. Deep Purple’s storage technology will have a capacity of 2000 Mwh. This provides much greater storage possibilities without occupying large areas of land. This is because the tanks can be stored under water.

Innovation Norway enabled the project

Løver says that the funds they have received from Innovation Norway have been an important contribution in getting the project started. It was also a symbolic recognition of how important it is to develop renewable hydrogen, or green hydrogen as it is also called.

Anders MellebyFremmerlid at Innovation Norway provides Deep Purple with financial advisory services. He believes that their work both inspires and lays the foundation for other actors – both inside and outside Norwegian trade and industry – to push the industry in the same direction.

“The transition from fossil energy to a renewable energy system is both complicated and resource-intensive. It is therefore important that Deep Purple also works to disseminate information and knowledge about the project”, says Fremmerlid.

Will supply island communities and oil platforms

“The possibility of storing hydrogen will not only provide more consistent access to wind power as an energy source, but the storage technology and capacity will make it possible to supply everything from island states to cities with green energy”, says Løver.

Together with offshore wind, the technology can provide local power supply as an alternative to laying power cables from shore.

In addition, clean energy from wind farms could also be used in large factories and oil platforms that are not connected to the electricity grid. Norwegian oil and gas production is known for its low CO2 emissions compared to other countries. However, gas turbines on Norwegian oil platforms still account for a quarter of Norwegian CO2 emissions.

Løver explains that this large-scale renewable energy initiative in the Deep Purple project represents a symbolic shift for the Norwegian oil and gas industry. The development and delivery of new energy systems such as this can provide opportunities for the long-term and significant development of sustainable jobs in Norway.

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