Mobile Offshore Wind Units are floating wind turbines that can move from location to location as and when there is a need for renewable power. They are ideally suited to provide power to oil and gas installations that require power for a limited period, typically until the production closes on that particular field. The Norwegian oil and gas industry has high ambitions and targets a cut in carbon emissions by 50% before 2030. There are principally four ways of delivering on the ambition:
- Electric power from shore
A controversial solution as the offshore power demands are enormous, and very few shore locations can deliver the power needed. A subsea cable and the land grid upgrade would require huge investments, and they are surpluses to requirements when the oil and gas production eventually come to an end.
In Norway, the projects triggering the grid upgrade are not solely responsible for the costs, as they are split evenly between everyone connected to it.
Furthermore, with the ongoing electrification in all parts of the society, electricity will become scarce. Therefore, electrification from shore will drive up electricity prices and grid transmittal fees for everyone and reduce the opportunities for developing more future-proof onshore industries.
- Carbon capture and storage (CCS)
Although carbon capture and storage has been around for a while, it comes at a high cost. It requires large and heavy equipment on the oil and gas installations, which have limited space and weight capacity. Retrofit on mature installations is challenging and often impossible. The process itself is inefficient due to high additional power requirements. This alternative is primarily relevant on greenfield developments and will likely not be able to deliver on the industry's needs. - Electric power from permanent windfarms
This is a good solution that may combine with power from shore. The main challenges with this alternative are:
a) There is a full stop on developing onshore wind power due to environmental issues.
b) Offshore wind farm development of any scale in Norway is not expected to happen until after 2030. That’s too late to meet the oil and gas industry’s ambitions. - Mobile Offshore Wind Units
MOWUs offer attractive flexibility. Odfjell Oceanwind will own and operate a fleet of floating wind turbines available for rent for a limited period. The MOWU is moored near the oil and gas installation and connected via a short subsea cable. At the end of the rental period, the MOWU, with all associated equipment, moves to a new site to supply power.
Being a mobile unit and a temporary installation, the MOVU does not require a separate license but may be considered an extension of the oil and gas production license. Odfjell Oceanwind’s WindGrid integrates with the installation’s micro-grid, thus providing uninterrupted power supply enabling shut down of all gas turbines during windy periods (which is most of the time in the North Sea.) Consequently, this will reduce emissions from power generation by 60-70% on most installations.
So why hasn’t this happened before? Well, as always, timing is everything: Until now, we haven’t seen the combination of a) high enough CO2-taxes to give reasonable business cases, b) technological maturity on wind turbine size, harsh environment floating structures and the WindGrid integration solutions, and c) a willingness from the oil and gas operating companies to make such brave moves towards a more sustainable future.
