Shell Eco-Marathon Europe 2016

Linde supports the event by supplying hydrogen and technical support to the teams who use fuel cell power units for their competition vehicles. As a partner, Linde adds considerable value to the event, particularly with regard to innovation, technology, sustainability, mobility and tackling future energy challenges.

As the world’s largest manufacturer of hydrogen plants, Linde covers the entire technology spectrum required to successfully use hydrogen as an energy carrier – from generation to refuelling. So far, Linde has equipped over 90 fuelling stations in 15 countries with innovative hydrogen refuelling technology. Furthermore, Linde is exploring new ways of producing renewable, zero-carbon hydrogen, using wind, for example.

Linde’s engagement in the Shell Eco-marathon does not only underline Linde's commitment to clean energy, it also dovetails with the Corporate Responsibility strategy, which consists of the three elements economic, social and ecological responsibility.

Hydrogen (H₂) is a highly volatile gas that can escape through the smallest of leaks. However, industry wide work in material technology, welding, valve technology and screwed joints means hydrogen can be handled and stored safely – this has been proven over the last decades by the industrial gas industry.

Hydrogen can be stored as a gas, a liquid or in solid materials. It has a high gravimetric storage capacity but a low volumetric one. Therefore to store a reasonable amount it either has to be compressed or liquefied to cryogenic temperatures, i.e. -253 °C. Hydrogen can also be stored at low pressure in the form of metal hydrides, which are used in various niche applications.

Small volumes of compressed hydrogen gas are commonly stored in pressurised cylinders at either 200 or 300 bar with between 10 and 50 litres of volume per cylinder. They are mainly used for laboratory and welding applications and also as small refuelling solutions for the demonstration of hydrogen-powered vehicles.

A pressure vessel is the most suitable solution for storing medium amounts of hydrogen. These are widely used for many different gases and are variable in volume and pressure level. This storage technology is suitable for small and medium hydrogen fuelling stations as well as industrial customers who require medium amounts of hydrogen for their production processes.

Hydrogen delivered in liquid form can be stored in volumes of up to 70,000 litres in super-insulated tanks -  Even though a  central liquefaction of hydrogen consumes more energy than a central compression, the advantage is a higher energy density due to the reduced volume and therefore the need for less storage – for certain locations such as fuelling stations this is a key factor.

Finally, the increase in unsteady wind and solar electricity production has led to excess energy that is not matching the demand of the grid. This calls for a storage solution for this excess energy until it is required.

One way in which the grid can be balanced is through the electrolysis of water. The water is split into hydrogen and oxygen with the energy stored in chemical form as hydrogen. These large volumes cannot simply be stored in tanks; instead, hydrogen is stored in salt caverns that can hold thousands of cubic metres of gas. Comparable facilities already exist in the United Kingdom and in the south of the United States. Depending on the geological conditions these caverns can store more energy than any other known energy storage technology.