Import choices shape infrastructure needs:

Smaller size of the hydrogen network when green fuels and materials are imported at scale and ammonia- or steel-making can relocate within Europe.

Only focusing on direct hydrogen imports cuts cost benefit in half.

Imports of derivative products like ammonia and methanol are preferred

Importing green energy and steel products (like HBI) has some advantages:

System costs fall by 1–10 % across a ±20% import cost range

In this range, cost-effective import volumes range between 1000 and 2000 TWh (~30-60 Mt H₂-eq)

No cost savings beyond imports of 3000 TWh (~90 Mt H₂-eq)

What we explored:

A full sweep of scenarios, interpolating between complete self-sufficiency and wide-ranging imports, plus sensitivity tests on low vs. high import prices and on excluding specific vectors to map the cost-effective space.

What we learned:

And greetings from the Tauernpass. I might not respond immediately -
busy gasping for air 🚵‍♂️🫁

In the paper, we also explore some more scenarios, e.g. with none or only one of the networks available. So if you're curios about a detailed infrastructure view on Europe's Carbon Management Strategy, have a look! We look forward to your questions! 🌱

Of course, this was made with #PyPSA 😉

We also find that the combination of both networks remains advantageous when climate targets are tightened toward net CO₂ removal. The CO₂ network allows effective utilization of unavoidable industrial emissions through capture and transport to utilization or sequestration sites

We show that dividing tasks between networks can be cost-effective: hydrogen pipelines deliver hydrogen from the South to industrial centres for fuel synthesis, while CO₂ pipelines transport captured emissions from these clusters to geological sequestration sites, e.g., in the North Sea.

Also: Captured CO₂ from some residual industrial emissions, or biomass for negative emissions, will need to be transported to geological storage sites.

With strict limits for sustainable biofuels and carbon sequestration of 200 Mt a year, large volumes of both molecules must be brought together for green fuel synthesis for aviation, shipping and the chemicals industry, but are rarely co-located.

Our team of @tuberlin.bsky.social researchers showed that combined infrastructure for hydrogen and CO₂ pipeline networks could reduce Europe's energy system costs by up to 5.3%, or approximately €41 billion per year. But development requires careful planning across borders and sectors.

✈️🚢🧪For Europe's green fuels for aviation, shipping, and chemicals: Should we pipeline H₂ to industrial CO₂ capture sites, or CO₂ to regions with better renewable resources for H₂ production?

📖 See our new study in @natureenergy.bsky.social on future carbon management: www.nature.com/articles/s41...

Such backup could be supported through sparingly used strategic reserves from multi-year hydrogen derivative storage, imported green fuels, or residual fossil fuel usage with compensation elsewhere.

This leaves us with the question how single-year system layouts perform when tested against other weather years. Interestingly, systems planned around years with known compound events proved quite robust across the other 61 years, thanks to network interconnections and strategically placed backup.

These year-to-year variations stem from both supply and demand factors:

On the supply side, wind energy variability is as the strongest factor - more than solar or hydro availability - but heat pump performance also plays a considerable role.

In our new study, we analyzed European energy system designs across 62 weather years (1960-2021). The results show that planning for the most challenging year requires 20% higher system costs compared to the lowest-cost year - a striking difference that exceeds most other sensitivity analyses!

A common criticism of energy system models is their reliance on single weather years, despite significant year-to-year variations.

But how can we ensure robust infrastructure planning in this case? What happens during rare events like the once-a-decade Dunkelflaute?

www.nature.com/articles/s41...