Europe's largest hydrogen plant runs on green power 

In the dune landscape of the Second Maasvlakte, construction of Europe's first green hydrogen plant is nearing completion. Under the name Holland Hydrogen 1 (HH1), Shell will use power from an offshore wind farm to produce an average of 60,000 kilograms of hydrogen daily and use it itself at the Pernis refinery. The refinery currently runs on gray hydrogen made with fossil fuels. Shell is thus taking an important step in making these plants more sustainable and in reducing CO2 emissions. At a later stage, other industries may also be supplied with green hydrogen by pipeline. 

Industry accounts for roughly half of energy consumption in the Netherlands. Moreover, it causes a quarter of CO2 emissions. That has to come down, and one of the alternatives industry has to fossil fuels like oil and natural gas is hydrogen. That is why an infrastructure for hydrogen is being worked on in the Netherlands.

Electrolysis

To make hydrogen, the plant uses alkaline electrolysis, a method of splitting water into hydrogen and oxygen by means of an electric current. "This is done in the ten electrolyzers totaling 200 megawatts positioned in a large hall on the site," says Bas van de Werff, Holland Hydrogen 1 project manager for Shell. "These and other installations on the site run on power generated by an offshore wind farm that Shell has set up in a joint venture with Eneco off the coast of Egmond aan Zee. Through an existing cable connection, this wind farm is connected to the 380 kV Maasvlakte substation. From this green power, and water from Evides, we make green hydrogen."

No prefab

For HH1's core business, electrolysis, Visser en Smit Bouw built a large electrolysis hall of concrete and steel, with 33 large trusses and 4,000 m² of roof and wall cladding. Van de Werf: "The floor is a thick concrete slab and, apart from a few blast walls, everything else is made of steel. Because of the many overpasses you have to pass through to get here and the restrictions on transport, it is difficult to work with large modules. That's why prefab is virtually not used for construction."

Blast walls

After generation in the electrolysis hall, the hydrogen is piped on the south side through three piperacks to two compressors that compress the gas to 50 bar. "This 60-megawatt plant is the only part of HH1 with a dynamic load on the foundation," Van de Werff explains. "To create a stable foundation, a six-meter-thick floor was poured on the compacted subsoil in front of the compressors with two thousand cubic meters of concrete. On top of that, bays were built 80 centimeters thick and with eight to 10 meter high blast walls. A leak in a compressor can produce an explosion in exceptional cases; this must not affect our neighbors. All other buildings and installations are founded on piles. This reclaimed land offers extremely stable ground conditions."

Arm-thick cable

On the north side of the electrolysis hall is an impressive 850-ton steel structure. "That's the setup for the air conditioners," Van de Werff clarifies. "Those ensure that we can get rid of the residual heat released during the electrolysis process. Ideally, we would like to reuse that residual heat in the port, but there is no infrastructure here for that yet. It might be a viable business case if buyers of heat settle on adjacent plots or a connection to the district heating system is established. On the east side of the electrolysis hall are the main electrical installations. The arm-thick 380 kV cable disappears here into the transformer station where the current is reduced to 33 kV. Five transformers against the electrolysis building convert that back to 670 V direct current. All this involves a lot of heavy cabling laid in culverts. You'd like the routing of that to be right the first time; you're not going to reroute that later."

Scandinavian main building

Also on the compact, well-stocked site are an oxygen ventilation pipe, an emergency hydrogen ventilation pipe, a metering station, a small building for water treatment and an auxiliary building with servers. "Not to mention the main building with all the control systems," Van de Werff adds. "That stands at the traffic circle outside the plant site fence. The nice thing is that here, on top of the concrete basement with all the installations for the control systems, we are realizing a superstructure made entirely of recycled materials. For an industrial application, I think that is quite special. The example was an elementary school built by Visser & Smit Bouw in the center of Rotterdam. Together with wood specialist De Groot Vroomshoop, we are making a representative main building here that should give a Scandinavian feel because of the wood used. Of course, it also fits beautifully into the dune landscape of the Maasvlakte. The round fence, which on drawing was still drawn a closed sand barrier, will probably just become an open fence. " 

"Initially, the hydrogen will find its way to our refinery and chemical plant in Pernis," Van de Werff concludes. "We want to expand that to other industrial customers as soon as possible. Once more trucks are running on hydrogen, we could also supply them with green hydrogen. Shell is taking the lead with this investment when it comes to renewable energy production."