Building the perfect toolbox for a low-carbon world

By Truls Normann, Aker Solutions

Subsea power distribution systems, enablers for long-distance subsea tie-back developments and energy intensive processing activities on the seafloor, can also be used for wind
Subsea power distribution systems, enablers for long-distance subsea tie-back developments and energy intensive processing activities on the seafloor, can also be used for wind (illustration: Aker Solutions)

Subsea technologies can accelerate decarbonisation across oil and gas, electrification and renewables, shares Truls Normann, senior vice president for subsea energy transition at sector specialist Aker Solutions.

Technology will play a central role in meeting the demands of the global energy transition across reduced-emission oil and gas, renewables and other low-carbon initiatives.

And offshore expertise and experience, particularly subsea, will be especially valuable as the energy sector – across all of its elements – looks to lower costs, boost reliability and increase efficiencies.

Because no one element, on its own, will be able to meet the combined challenges of decarbonisation, energy security and energy access; the transition ahead will by definition require action across multiple fronts.

Companies including Aker Solutions believe that enabling and facilitating technologies designed to serve the whole gamut of future energy, in all of its low-carbon forms, will therefore be crucial to achieving global ambitions.

The opportunities and challenges ahead dovetail with a proven heritage and capabilities honed in the harshest of environments over many decades, and provide confidence that the right solutions are in place for tomorrow’s energy – whether offshore wind, low-emission gas, electrification or others.

Doing more with less
Emission reductions from traditional energy projects will be an essential element of the transition in the immediate term, with the global shift from coal to gas a key enabler – particularly in high-demand markets such as Europe and Asia Pacific.

Subsea gas compression technology provides a route to improved recoverability and offers significant carbon efficiencies compared with traditional alternatives, across not only equipment but also production and operations.

The seabed system is composed of compressors, pumps, scrubbers and coolers. Features include magnetic bearings, low voltage and electric drive motors. Aker Solutions’ concept eliminates the need for an offshore platform and, because it is closer to the wellhead, increases output on the back of a reduced pressure drop. Compared to topside compression this allows for reduced CO2 emissions in the range of 20-60%.

Subsea Substation for electrification with transformer, switchgear and subsea termination assemblies (STAs) for distribution to various assets
Subsea Substation for electrification with transformer, switchgear and subsea termination assemblies (STAs) for distribution to various assets (illustration: Aker Solutions)

The company proved its concept alongside alliance partners MAN Energy Solutions and ABB at Equinor’s Åsgard project off Norway, where a gas compression system was originally installed in 2015 in 300 metres of water and where a fifth module is due to be delivered in 2024. This enables prolonged plateau production as the pressure in the reservoir naturally declines.

Availability at the 25-MW Åsgard installation is nearly 100% over the last 6 years, recovery was increased by 20% and CO2 reductions have been in the range of 40% compared to producing from a floating platform. In media the client Equinor states that it has been a huge success, running like clockwork, and performed as a money machine providing additional recoveries with a value in the range of 200 billion NOK/20 billion euros.

Going big in Australia
Even more impressive results are expected at Chevron’s massive Jansz-Io development off Australia.

The EPC contract for the subsea system covers three compressor modules, two subsea pump modules, all-electric control systems and actuators, and structures including mud mats, HV power distribution systems, and spare modules and other equipment. The Alliance partners MAN ES and ABB are providing the 11.5-MW compressors and large subsea transformer units, respectively.

Subsea compression system for the Jansz-lo field, offshore Western Australia (illustration: Aker Solutions)
Subsea compression system for the Jansz-lo field, offshore Western Australia (illustration: Aker Solutions)

Aker Solutions plan to deliver the first installation in 2025, resulting in a significant reduction in energy consumption and emissions across the project lifecycle.

Other benefits include reduced size and steel weight compared with a platform, zero hydraulic discharges and, on the back of remote operations, improved health and safety.

And the experiences gained will impact well beyond the specific project in question, and even the specific sector, addressing key asks from the energy transition. These extend to unmanned facilities, module construction, subsea electrical power and HV connection system technologies, subsea pumps and variable speed drives, deep-water deployment distant from shore, and cable development, among others.

Power the change
Many of those technologies are also well positioned to be tested in the electrification projects now taking shape in markets including Norway and the UK.

Subsea substations to facilitate long step-out power from shore distribution will require transformers, switchgear and subsea high voltage terminations that not only provides power to offshore oil and gas platforms, but also have the capability to be a hub for connection of offshore wind arrays. In such cases, surplus power from renewables can be sent the other direction to shore.

And companies such as Aker Solutions, which has experience both subsea and topside engineering, are well-placed to analyse overall system architectures and to identify optimal customer solutions, whatever the demands.

It is the kind of experience that has led to the development of subsea HV hubs, which require a fraction of the steel of traditional HV platforms, feature simpler logistics and cost-effective fabrication – and capex savings of up to 40%.

On a related front, another Aker Solutions company Benestad is currently developing 66 kV infield cable terminations with funding from the UK government along with wet mate connectors funded by Norwegian government and industry partners, to be qualified by 2024.

Aker Solutions can design and deliver both topside and subsea power collector substation solutions
Aker Solutions can design and deliver both topside and subsea power collector substation solutions (illustration: Aker Solutions)

Deploy and evolve
The horizons for this technology are wide and the solutions are adaptable. A subsea substation installed for electrification can, once the oil and gas assets are decommissioned –because of a depleted reservoir, or due to COtaxes etc – be used to export wind power to shore, or as part of a hydrogen production facility.

Further, this technology can also be offered as a subsea hub for wind power collection, as an alternative to bottom-fixed or floating solutions. The subsea substation concept is based on a “building block” design that will allow 300 MW units to be placed on parallel to accommodate 600 MW or 900 MW – or more – for power collection and export to shore at 220 kV. Utility-scale wind, wave and tidal could all benefit.

Aker Solutions’ subsea ZEUS concept, meanwhile, enables clean natural gas-based power production with instant carbon capture and reinjection in a single station. The technology can be used to improve hydrocarbon production while also removing the CO2, it can be dedicated to pure power production, or it can be co-located with renewables as dispatchable base power to address intermittency issues.

And onshore should not be ignored. The hydropower sector is expected to double as part of the global energy transition with attention focused in particular on the large battery effect of pumped storage and next-generation designs that require smaller reservoirs and a reduced overall footprint, but at the same time high power output to cover peak demands during the day. Crucial to success will be similar pump technology, connectors and control systems that power subsea.

Ambition and endeavour
No one should underestimate the size of the challenge facing the energy sector. The speed of low-carbon development is already being constrained by global supply chain issues, increased costs, post-covid complications and project delays; and the logjam may get worse as 2030 deadlines approach.

This will be further complicated by the parallel requirements of meeting growing demands for both energy security and energy access; natural gas in particular will continue to play an increasing role in the decades ahead.

Aker Solutions is in the perfect position to make a difference across all segments of the energy transition, whether that is dramatically cutting the emissions of oil and gas, enabling electrification, expanding renewables or facilitating the roll-out of hydrogen, CCS, next-generation hydro and ocean energy at scale.

As a company we are living up to our own ambitions – with the target of one-third of our revenues from renewables and low carbon solutions by 2025 and two-thirds by 2030 – by building on a proven heritage in subsea technologies and taking the steps necessary to realise the significant changes required, rather than simply waiting for opportunities to present themselves.

This is about focusing on the sweet spot where new solutions and the expertise we have built working offshore and subsea overlap; combining the best of what has come before with the innovation, expertise and discipline necessary to tackle the challenges ahead.

Aker Solutions – armed with the right technology, the proven know-how and the strength of our team – has faith in what is possible, and what can be achieved across the energy transition together with our partners, customers and suppliers.