Subsea hydrogen storage concept for CO2-free energy production

As the world looks to reach a cleaner future and stop relying on fossil fuels, we will need to replace this with other significant energy sources.

Wind, sun and marine renewable energy, such as wave and tidal might help us reach this goal, but we will also have to take into account other building blocks of energy transition puzzle, such as hydrogen.

When compared to batteries, hydrogen as a clean energy carrier is said to be more efficient for large-scale storing.

This could be a key element in helping heavy industries as well as transportation sector to move away from fossil fuels.

However, producing and storing clean hydrogen has not been an easy task for many countries.

To this end, engineering giant TechnipFMC is developing a new technology in Norway that involves using electricity from offshore wind farms to make hydrogen, which is then stored subsea.

The so-called Deep Purple project aims to deliver alternative energy source as well as help coastal nations around the world reduce their carbon footprint.

The Deep Purple concept was founded at the Research Council of Norway’s Idea Lab in June 2016.

Partners were TechnipFMC, Ocean Hyway Cluster, Energy Valley and Sintef.

TechnipFMC took ownership to the project and has led the development process since, including collaboration with the founders.

The company is currently completing Deep Purple phase 2 and defining its next step, which will start next year as a small pilot.

To see what storing hydrogen subsea brings to the table we went straight to the source.

“Main advantage is the free area available,” says Marit Mork – manager Innovation Projects, Deep Purple at TechnipFMC.

“When sizing an energy storage system to tackle seasonal variations in wind, the amount of energy to store is so large that it will be challenging to fit into a floating structure.”

“If batteries were to be used it would be even more spacious,” she said.

It could also be mentioned that us in TechnipFMC coming from the subsea industry, developing a subsea storage system is considered as well within what is feasible.

One of the first uses for the Deep Purple hydrogen storage system could be in the oil and gas industry, where TechnipFMC’s technology could help to provide oil and gas platforms with clean energy.

Gas-powered platforms could instead be hooked up to a system of wind turbines and hydrogen fuel cells, giving them access to clean energy on demand.

Deep Purple could potentially provide oil installations with a stable 35 MW energy supply throughout the year and help cut carbon emissions by roughly 80 per cent.

“The main challenge is probably the cost level competing with gas turbines on oil & gas installations, however, the cost level of wind and hydrogen technologies are rapidly decreasing,” said Mork to Offshore Energy – Subsea.

Also, the system could help supply green energy to remote island communities around the world, many of which currently rely on diesel generators.

Offshore large-scale hydrogen production from wind farms for pipeline export is also part of the concept.

Furthermore, TechnipFMC sees this technology playing an important role in supplying the shipping industry with clean fuel.

The concept also allows international shipping to bunker hydrogen at open sea for export or vessel propulsion.

Another scope is an integrated system for safe subsea hydrogen storage and distribution at ports around the world.

“We also consider using the subsea storage solutions for local hydrogen storage in harbors/close to coast,” said Mork.

“Then this solution will free up space onshore and be located far away from people, which is regarded safer than storing large amount of hydrogen onshore.”

The sector needs to greatly reduce its carbon emissions, and hydrogen fuel cells have been identified as one of the best ways of powering larger ships in future.

One other aspect of the Deep Purple project is the impact it could have on Norway’s growing hydrogen industry.

This month, Norway’s GCE Ocean Technology and Ocean Hyway Cluster signed a collaboration agreement with TechnipFMC to contribute to the development and commercialisation of the different Deep Purple concepts.

“We look upon the different Deep Purple concepts as most interesting. On behalf of our members we look forward to following up and hopefully contribute to reduced emissions and added value in the years to come,” said Owe Hagesæther, CEO in GCE Ocean Technology.

As leading ocean industry clusters; GCE Ocean Technology and Ocean Hyway Cluster represent more than 200 organisations.

“The cluster contributes with valuable networks, communication activities and market understanding as well as an opportunity to connect TechnipFMC with other member companies that have technologies that can be integrated into the total solution,” said Mork.

Recently TechnipFMC transferred the Deep Purple project to its Norwegian subsidiary KANFA.

“There will be a need for increased collaboration with industry and technology players as we approach the commercial stage for the Deep Purple Project,” said Harald Bjørn Hansen, director Deep Purple BU at KANFA.

Norway is the third-largest exporter of natural gas in the world.

Workforce from that industry is now starting to enter green industries such as offshore wind and hydrogen production.

As mentioned above, TechnipFMC, through its Norwegian subsidiary Kanfa, aims to enter the next phase of its Deep Purple project later in 2020, where it will seek to further develop and qualify its subsea hydrogen storage facility so it is ready for commercial use in the next few years.

The company is also working on other partnerships that will cover the production of hydrogen using offshore wind turbines.

According to Mork, we could see the first Deep Purple offshore demo in 2025.