How engineers design the hydrogen network of the future

On a map, this connection may look like little more than a line between a few locations. In reality, that line represents years of studies, calculations and engineering decisions.

Now that the main route for the Southwest Netherlands Hydrogen Network has been established, engineers are developing the detailed design. What does that involve? Far more than most people might expect. Designing a pipeline is about much more than the pipe itself. We spoke with the engineering team behind the Southwest Netherlands Hydrogen Network.

The pipeline is only one piece of the puzzle

When people think of an underground pipeline, they often picture the pipe itself. In reality, much of the design is shaped by everything that is already there.

The challenge is not just designing a new pipeline, but fitting it into an environment that is already busy, both above and below ground. Underground, existing cables and pipelines carry electricity, gas, water and telecommunications services. Above ground, roads, railways, waterways, buildings, farmland and natural areas all place demands on the available space.

Whenever possible, new hydrogen pipelines are routed alongside existing infrastructure corridors. This helps make efficient use of the limited space available, reduces the need for additional land use and preserves room for future infrastructure projects. Strict safety regulations and separation distances always apply.

That said, this is not always possible. In some locations, the subsurface is already crowded with existing infrastructure. Elsewhere, railways, canals, residential areas or environmentally sensitive locations create constraints. A solution that works perfectly in one area may become unfeasible just a few hundred metres further along the route.

'The most elegant design on paper is not always the best solution in practice. The challenge is to create a design that is technically feasible, safe, reliable and well integrated into its surroundings.'
Theo de Visser, Lead engineer, Southwest Netherlands Hydrogen Network

This is why engineering is as much about balancing information, technical requirements and local circumstances as it is about designing the pipeline itself. In the end, the pipe is just one element of a much larger puzzle.

Understanding what lies beneath the surface

Before engineers can start designing the route, they need a clear understanding of what is already underground.

Maps and utility records provide an initial picture of existing cables and pipelines, but that information must always be verified. One way of doing this is through trial trenches. By excavating at selected locations, engineers can determine the exact position of existing infrastructure, validate available data and reduce the risk of unexpected issues during construction.

The ground itself is also investigated in detail. Specialists carry out borehole surveys and geotechnical testing to understand soil conditions and install monitoring wells to track groundwater levels before and during construction. Only once these conditions are fully understood can informed design decisions be made.

How ground conditions shape the design

Ground conditions play a much larger role than many people realise. Sand, clay and peat all behave differently, requiring different engineering solutions. For that reason, engineers assess every section of the route individually to determine the most suitable design approach

Groundwater conditions are equally important. In some areas, pipelines can be affected by buoyancy forces, causing them to move gradually upwards over time if no mitigating measures are put in place.

Engineers therefore look beyond the conditions of today. They assess how the pipeline is likely to behave over the coming decades and determine which measures are needed to ensure it remains safe, stable and reliable throughout its operational lifetime.

'There is no standard solution underground. Every kilometre of the route requires engineering decisions that reflect the local conditions.'
Jan Wolbink, Engineer, Southwest Netherlands Hydrogen Network

No two pipelines are exactly alike

Not every part of a hydrogen pipeline is designed in the same way.

The volume of hydrogen that needs to be transported determines, for example, the required pipeline diameter. Much like roads need additional lanes where traffic volumes increase, hydrogen pipelines require greater capacity where demand is higher.

The wall thickness of the pipeline may also vary. In locations where additional protection is required, such as areas where multiple pipelines are routed close together, a thicker wall can be specified.

Different construction methods are used as well. In some locations, pipelines are installed in open trenches. In others, trenchless techniques such as horizontal directional drilling are preferred, for example beneath roads, railways, waterways or orchards. The chosen method depends on permitting requirements, environmental considerations and the space available for construction.

More than technical drawings

Engineering involves far more than producing drawings.

A single route may require hundreds of detailed drawings, but these represent only a fraction of the work involved. Engineers also perform calculations, assess risks, define safety measures and develop construction specifications. Every design decision is carefully substantiated to demonstrate why a particular solution is the most suitable for the local situation.

'Behind every drawing lies a combination of analyses, calculations and expert assessments that determine whether a design is safe, feasible and future-proof.'
Ruud van Meenen, Engineer, Southwest Netherlands Hydrogen Network

The design is then reviewed by specialists from multiple disciplines before it can be used to support permitting procedures and, ultimately, construction.

Where the network begins

The hydrogen network of the future does not start with excavators or steel pipelines. It begins years earlier, with the people who investigate what is possible beneath the surface.

By bringing together thousands of data points, technical requirements and stakeholder interests, engineers lay the foundations for a network that will safely and reliably transport hydrogen to the places where it is needed most, helping to support the transition to a more sustainable energy system.