The only issue is, where are we going to get the huge quantities needed to overcome the climate crisis?
This article begins with comments from Dr. Rudolph Kalveks, a retired executive. His PhD was in theoretical physics. He asks:
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Might it prove possible to harness hydrogen as a “green” fuel using electrolysis and electricity from renewables? Rolls Royce are investing in developing the equipment to do this on an industrial scale.
But as the article concedes, “there is still some work to be done to make this process cost-effective”.
Important topics omitted from the brief article include the many safety, energy efficiency and cost issues associated with the conversion, storage, transport and use of hydrogen.[1,2]
Also, there is no mention of the alternative route for the manufacture of hydrogen by the high temperature cracking of water, as is feasible at nuclear power facilities, and which is claimed to be more cost-effective.[2, 3]
The references above are at the foot of this article.
Rolls Royce say that the answer is to use electrolysis, an electrochemical process that uses electricity to break water into its constituent parts: hydrogen and oxygen. So we are developing mtu electrolyzers with outputs of up to 2 MW that can be scaled up to over 100 MW.
To do this we have acquired a stake in Hoeller Electrolyzer, a specialist company that develops and manufactures the cell stack (the core component of the electrolyzer). The shared aim we have with Hoeller Electrolyzer is to develop a solution to produce hydrogen cheaply, and on a large scale using green electricity. This is an ideal add-on for an mtu microgrid. It creates the opportunity to store and use solar and wind power which will make an important contribution to the energy transition.
What is electrolysis?
Large-scale electrolysis works on the same principle as those electrolysis experiments in physics and chemistry lessons, in which two electrodes are suspended in a water bath.
In an electrolyzer, water is broken down into its components hydrogen and oxygen by an electrochemical reaction. In contrast to the electrolysis experiment at school, however, a membrane is used instead of electrodes. Current is passed through this membrane into the water, producing hydrogen at the negative cathode and oxygen at the positive anode. This process takes place in a so-called cell, hundreds of which are stacked on top of each other in such a way that they produce the required amount of hydrogen as economically and effectively as possible.
Why hydrogen?
Because it contains no carbon and cannot produce harmful carbon dioxide (CO2) when powering fuel cells or hydrogen engines. Sounds fairly straightforward. The trick, though, is to ensure that no CO2 is produced during production of the hydrogen – as is partly the case when hydrogen is obtained from natural gas says Armin Fürderer, Head of net zero solutions, Rolls-Royce Power Systems.
Ensuring no C02 is produced calls for 'green' hydrogen production that doesn’t give off carbon emissions, and that's where solar parks and wind turbines come in – supplying the electrolyzers with electricity generated with zero CO2 emissions. The collected hydrogen from the electrolyzers can be used in a variety of ways: In fuel cells, the hydrogen is used to generate electrical energy again as needed. Or it is used to power hydrogen engines. Either way, electricity can be fed into the grid or used to power vehicles or ships. Alternatively, the green hydrogen can be used in industry and replace so-called gray hydrogen - i.e. hydrogen from natural gas.
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