The rise of offshore hydrogen production at scale

The potential for Power-to-X (P2X) and offshore hydrogen production is significant - but realising this potential is not without its challenges. How can we scale this new technology and still make it safe and profitable?

One corner stone is building on years of knowledge and expertise. Let’s explore some key technical and economic considerations.

According to the International Energy Agency (IEA), total offshore wind capacity is forecast to more than triple by 2026, reaching close to 120 GW.

Not unlike the early years of offshore wind, we’re now standing on the cusp of a new era of offshore hydrogen production of industrial volumes.

While it took decades for wind and solar to achieve grid parity with fossil fuels, green hydrogen needs to be cost-competitive with ‘grey’ hydrogen within a decade.

As described above, the location and capacity of the electrolysers are two important factors when deciding your project design.

Electrolysis is a well-known and thoroughly tested technology. However, to achieve scale and drive costs down, it will be important to have more powerful and efficient electrolysers - not only for offshore hydrogen but for the entire hydrogen spectrum.

For now, projects using onshore rather than offshore electrolysers tend to be less expensive - but as production scales, this is expected to shift past 2030 (source: BloombergNEF).

Many of today’s largest commercial electrolyser units have power limits of 5 MW. In the coming years, it is expected to grow to 10 MW. This is not insignificant given that less than a decade ago “big” was measured in kilowatt.

But for hydrogen from offshore wind, even 10 MW electrolysers won’t be enough. For this reason, modular approaches have been introduced where you group electrolysers together – such as using 100 pcs. of 5 MW units. For offshore constructions, this calls for more compact solutions with a reduced footprint, lower weight, and solutions optimised for operating efficiently under harsh offshore conditions.

Although often overlooked, it is also critical to consider operations and maintenance. Your offshore hydrogen facility should operate for the next 20-25 years, and an electrolyser unit will typically last 7-10 years. So, in addition to traditional maintenance, during the lifetime of the facility, electrolyser units will need to be replaced once or twice - without impacting operation of the other units in the modular setup.

Another and arguably just as important aspect is access to power supply and maintaining a stable electrical grid. Wind turbines have traditionally been designed to be connected to the grid directly, but as a new development some offshore wind farms for hydrogen production are not intended to be connected to the grid.

In the last 5-8 years, we have developed electrical concepts for both island mode of offshore wind farms as well as off-grid operation of electrolysers far from shore. Test runs on large offshore wind farms in operation have provided valuable knowledge and energy companies are preparing turbines for off-grid operation enabling price-competitive production of offshore hydrogen.

Building offshore platforms has been tried and tested for decades in both offshore wind and oil and gas. With the right expertise, several well-known elements can be adapted and retrofitted to offshore hydrogen production.

To transport and distribute the energy to end-users, there is currently no dedicated hydrogen grid network similar to that of natural gas and electricity. However, it is possible to retrofit and upgrade existing gas pipelines to transport hydrogen, which can contribute to solving a key constraint in its development.

This requires attention to differences between natural gas and hydrogen. Hydrogen molecules are considerably smaller than the main component of natural gas, methane. Therefore, it will be important to perform an integrity assessment and requalification of existing pipelines to identify potential risks of leakage, loss of integrity, and safety challenges.

At Ramboll, we have a long history within offshore wind – dating back to 1989 - and over four decades of experience in offshore platforms, structures, substations designs, and pipelines. Working on hundreds of projects have taught us that having the right team of experts ask the right questions is key – this is especially true when venturing into unchartered waters.

We believe that innovation drives success. Over the years, we have built successful partnerships to pioneer innovations, and we continue to do so in advancing Power-to-X and green hydrogen.

We use our experience and combine key disciplines to best consult you and your organisation in successful and profitable offshore hydrogen projects.