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Padlet - Perovskites : the future of solar ?

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Padlet - Perovskites : the future of solar ?

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Here is an interview of Daniel Hissel dealing with Hydrogen’s existing capabilities, as well as present challenges.

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Will hydrogen be the foundation for the clean energy of the future? Daniel Hissel, who was awarded the 2020 CNRS Gold Medal, provides an overview of existing capabilities, as well as present challenges.

Hydrogen is the most abundant atom in the Universe, and therefore represents a potentially unlimited resource. How can energy be extracted from it?
Daniel Hissel: 1 Hydrogen is not a primary source of energy, but rather an energy vector. It must first be transformed into dihydrogen, its molecular form (H ₂), so that it can be transported, stored, and ultimately used to draw energy. There are two primary methods for doing so. The first consists in burning it in turbines, like a traditional fuel. The advantage is that, on an equal weight basis, it will enable three times more thermal energy to be released than petrol. What's more, this combustion is decarbonised, as it only produces water, and no carbon dioxide (CO ₂). As a result, dihydrogen is being considered for consumer aviation, as it would allow "clean" planes to fly, although nitrogen oxide and other pollutants are emitted during combustion.
The other method, which we are working on in our laboratory, is to use hydrogen fuel cells to produce electricity and heat. In short, such cells involve a reaction between dihydrogen and oxygen: the dihydrogen molecule is dissociated, and hydrogen atoms combine with oxygen from the air to form water. There is also the emission of heat and an exchange of electrons, which generates an electric current.

Lets talk about H₂ itself. It is not naturally present in nature but must be produced. How is that done?
D. H.:The most common method today is the reformation of methane (CH ₄) using overheated steam. The methane and water combine to form both H ₂ and CO ₂. In general, 95% of H ₂ is produced in this way by resorting to fossil fuels such as gas, petroleum, and - worse still, coal. This is a shame, for while the electricity generated by hydrogen fuel cells is green, it is obtained from "grey" H ₂, which only shifts the problem. It is therefore crucial to "green" the sector.

To do so, there is a well-known technique, known as electrolysis, which simply consists in producing the opposite reaction to the one that occurs in the fuel cell. In plain terms, passing an electric current through water makes it possible to obtain dihydrogen and oxygen. Today electrolysis represents a mere 5% of H ₂ production. This proportion can of course be increased by manufacturing more electrolysers, but this raises the question of the electricity source powering them, which must be renewable - either solar or wind. That said, the electricity in the French network is already highly decarbonised, since it is primarily of nuclear origin. Of course it would be ideal to expand the amount of renewable energy in the French mix, but this challenge exceeds the framework of the hydrogen sector. In any event, we are not yet in a phase of energy degrowth, so we must keep in mind that replacing fossil fuels with hydrogen produced through electrolysis will mean a rise in global electricity production.

Fuel cells were invented in 1839. Shouldn't there be one in every home today?
D. H.: If this is not so, it is because for a long time, other types of generators, such as electrochemical cells and batteries, were preferred, and efforts to develop hydrogen fuel cells were sporadic. But it is worth looking back at the changes that have occurred over the last twenty years. When I began working on the subject, fuel cells were extremely expensive, with a short lifespan and weak performance. Our laboratory's efforts, as well as those of all players in the field, including industrial actors, have focused on these three aspects. As a result, for the same amount of power, the price today has been divided by thirty, and the volume required by fifty. Lifespan has been multiplied by 40 or 50, depending on the use.

What actual performance have all these division and multiplication factors made possible?
D. H.: The US Department of Energy (DOE) established a performance benchmark for the automobile transportation industry, by imagining the replacement of combustion engines with fuel cells, on the basis of an annual production of 500,000 units. To make this replacement possible, a lifespan on the order of 5,000 to 8,000 hours, or 400,000 kilometres, would be necessary. Its density would have to be under 1.5 kW/l (the volume of a fuel cell producing 1.5 kilowatts must be less than a litre). With regard to energy conversion efficiency, 60% of the chemical energy of H ₂ molecules must be converted into electrical power.

Finally, the cost must remain below 40 €/kW, as approximately 30-40 kW are needed to equip a car, equivalent to about 1,600 € in the case - used as a reference - of electric hybridisation. So where do we stand today? The density target has been met. Durability now reaches 4,000 hours, and 55% efficiency has been attained. The price comes out to €50-60/kW for an annual projected production of 500,000 units. In short, all of the objectives have either been achieved or are in sight.

How do you explain such progress?
D. H.: Well, first, there was plenty of room for improvement! There were also numerous factors of progress, half of which came from basic research, and half from the optimised management of fuel cells, for example via artificial intelligence. Upstream research enabled progress in the field of materials, in particular nanostructured materials that reduce the volume of fuel cells. The membrane, in which electrons are exchanged, also improved greatly with the development of new polymers. The use of platinum, an expensive but indispensable catalyst, was optimised. That's about it concerning basic research. Then there is the integration of cells within their applications, which is what we focus on here.

This specifically involves improved management of fuel cells, for instance by enhancing energy performance and durability. We are working on all of the auxiliaries necessary to their functioning: electrical energy converters, cooling systems, real-time diagnostics of battery health, and sensors providing estimates of their remaining lifespan. Beyond the progress made on the cell and its use, there has been growing awareness of the need to reduce greenhouse gas emissions. Industrial actors - car manufacturers in particular - have decided to invest in this promising sector. What's more, the maturity of this technology enables other applications, which further encourages industrial actors considering investment.

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Will hydrogen be the foundation for the clean energy of the future? Daniel Hissel, who was awarded the 2020 CNRS Gold Medal, provides an overview of existing capabilities, as well as present challenges. Hydrogen is the most abundant atom in the Universe, and therefore represents a potentially unlimited resource.

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This French article talks about Hydrogen’s advantages to make it a key component of our future energy mix, as well as the obstacles that will need to be overcome.

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Energy, its use and accessibility are one of the main challenges for the future of our civilization. The world's population continues to grow, and our energy needs show no sign of decreasing any time soon, despite efforts to limit them. In addition, a closer look reveals that many new technological developments are associated with energy-as are, unfortunately, many conflicts and geopolitical tensions.

In this context, and taking an objective viewpoint, what would be the best solution for a future energy supply? First of all, it must be abundant and sustainable, based on resources that are renewable on the scale of a lifetime. It must be clean and environmentally friendly, and should not generate greenhouse gases. It must also be accessible to all, everywhere on the planet. Lastly, it must have many uses. Whether hydrogen would be a good candidate depends on various criteria.

First of all, it is worth noting that hydrogen is the most abundant element in the universe: 75% in terms of mass and 92% in number of atoms. This is a strong asset, even though it must be emphasized that it is only rarely present naturally in the form of dihydrogen on Earth. It must therefore be produced (making it an "energy vector" as opposed to a fuel), hence the second criterion, namely sustainability.

On this point, the opponents of hydrogen often put forward the inefficiency of its production chain. Indeed, the yield of electrolysis is around 70%, which can seem low compared with fossil energy sources that are immediately available. Yet this must be considered in light of the excellent electrical yield of hydrogen fuel cell systems, which can exceed 50% -a very high percentage in relation to that of thermal installations. Last but not least, in terms of financial cost, the original source (wind, sunlight, etc.) is free. In short, the yield issue is not a valid argument against the use of hydrogen. But other criteria must also be met, such as accessibility anywhere on the planet.

From generators to aerospace applications

From a technical point of view, hydrogen here again ticks all the boxes. Sunlight and wind are widely available across the globe. It is even possible to produce hydrogen at home, with a few solar panels on the roof or façade of individual houses or buildings. However, the cost of electrolyzers and hydrogen fuel cells must be further reduced to make them affordable to the greatest number of users. This can be achieved by improving the devices' energy efficiency and durability, and by increasing the volumes produced-in other words through industrialization.

Also, are the potential applications of hydrogen energy numerous and varied enough? The answer is yes, definitely! As mentioned above, it is an energy vector, and one that is also compatible with electricity: it is remarkably easy to switch from hydrogen to electricity with a hydrogen fuel cell, and from electricity to hydrogen with a water electrolyzer-all without emitting any pollutants. It is therefore a long-term electricity storage solution that can be used in all current or potential electrical applications: clean and quiet stationary generators, 1 small portable supplies for tourism, electricity, hot water and cooling generation systems for buildings, long-term storage on electrical networks or micro-networks...

One of these applications, and not the least, is worth looking into: the power supply of electric vehicles (cars, trucks, buses, trains). The main "added value" of hydrogen over battery-powered electric engines is a sharp increase in range: a family car can cover about 100 kilometers (more than 60 miles) on just 1 kilogram of hydrogen. In addition, the charging time can be be reduced to only a few minutes to fill up. This is why hydrogen energy was a recurring theme in Belfort on December 11 to 14, 2017, at the IEEE (Institute of Electrical and Electronics Engineers) Vehicle Power and Propulsion Conference (VPPC) which I chaired, and where hundreds of experts got together to discuss electric mobility. It is also necessary to bear in mind that hydrogen can supply all or part of the power for other kinds of vehicles: warehouse forklifts operating 24 hours a day, delivery and surveillance drones, agricultural and cargo handling equipment, not to mention aerospace applications, which gave rise to the initial development and engineering efforts for this technology.

Abundant research

To bring the tremendous potential of hydrogen to fruition, a great deal of research is underway in the laboratories, like, for examples, that done in the framework of the GDR HysPàc. As for me, having trained as an engineer, I have been pursuing a top-down approach for nearly 20 years now, in an effort to accelerate the development of this technology, working with established and would-be industry players in the sector to identify the technical obstacles and translate them into scientific challenges. This method is highly complementary to the more bottom-up, "material-to-object" approach being developed in the CNRS chemistry and electrochemistry labs. By tackling the issue from both ends, we can work more efficiently and make faster progress.

My main research activities focus on enhancing the energy efficiency and sustainability of hydrogen energy systems. By seeking to identify the condition of the hydrogen fuel cell, concentrating on the remaining operation time (in relation to a given or estimated operation cycle), and by optimizing control of the system based on this information, we have been able to significantly improve the technological maturity of hydrogen energy and assist industrial players on an international scale, while launching our own startups. This research is conducted with teams from the CNRS Federation for Fuel Cell Research ( FCLAB). It is a collective interdisciplinary effort, which is perhaps even more essential here than in other fields, given the nature of our subject, which requires expertise in electrical, mechanical, thermal, electrochemical and materials engineering, as well as in economics and the other human and social sciences. This kind of joint endeavor is no doubt what will enable hydrogen to play the role that it deserves in the energy landscape of the future.
The analysis, views and opinions expressed in this section are those of the authors and do not necessarily reflect the position or policies of the CNRS.

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What advantages does hydrogen have that could make it a key component of our future energy mix? What are the obstacles to be overcome? Daniel Hissel, a respected hydrogen specialist and recent winner of the prestigious Blondel Medal, shared an update on the topic at an international conference on electric vehicles, held in Belfort, France in December last year.

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Here you will find lots of informations about Hydrogen as an energy vector. You can also navigate on the website and find many details about other renewable energies. Happy reading !

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By way of comparison, global energy consumption in 2017 was around 13,800 million tonnes of oil equivalent (Mtoe) (all energy is stated in terms of the energy capacity of a tonne of oil); hydrogen therefore represents 0.4% of this quantity in terms of mass, but 1.2% in terms of energy (1 tonne of Hydrogen equates to 2.86 toe in heat equivalent).

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This Italian video is about the process of Carbon Capture & Storage which is used to produce Blue Hydrogen.

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How to capture and valorize CO2 - Energy Transition | Eni Video Channel

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This French video explains how a fuel cell works.

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[Comment ça marche ?] L’électrolyseur et la pile à combustible

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Padlet - Is renewable energy truly renewable ?

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Padlet - Is renewable energy truly renewable ?

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Résumé des avantages et inconvénients du dihydrogène en tant que vecteur énergétique

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Résumé des avantages et inconvénients du dihydrogène en tant que vecteur énergétique

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Maintenant que vous en savez plus sur cette source d'énergie que constitue le dihydrogène, il est temps de discuter des avantages et inconvénients de celle-ci ! Nous vous proposons donc ci-dessous une fiche récapitulative des plus et des moins du dihydrogène.

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Nowadays, we have to think about solutions for reducing our carbon emissions. Our budding engineers Anaïs, Capucine and Laura relate a BBC podcast about hydrogen power in order to inform you about “net zero”.

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If you liked this Padlet about dihydrogen and would like to know more about it, then we recommend :

A few websites on the subject in different languages ;

Padlets dealing with renewable and alternative energies (Some are in English and others are in German.) ;

Didactic videos about dihydrogen in various languages (production process, means of valorisation...).

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Ci-dessous vous trouverez quatre fiches techniques sur le dihydrogène afin de mieux comprendre l’enjeu qu'il représente en tant que vecteur énergétique.

Si vous souhaitez en apprendre plus sur le dihydrogène mais de manière plus attractive, alors nous vous invitons à cliquer sur le lien ci-dessous qui vous emmènera sur un Prezi créé spécialement pour vous!

https://prezi.com/p/edit/dfhegw66vygr/

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Here is a link to a podcast about renewable and alternative energies. We invite you to listen to it and learn more about solutions to reduce our carbon emissions in the future, using for example hydrogen power.

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BBC Inside Science - Halfway to net zero; hydrogen as a fuel; Fagradalsfjall, Iceland's active volcano - BBC Sounds

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Catch up on your favourite BBC radio show from your favourite DJ right here, whenever you like. Listen without limits with BBC Sounds.

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Here you can find all the definitions you need (in alphabetical order) so as to understand the documents.

Do not hesitate and click on the link bellow ! It will lead you to a quizlet with some flashcards about our topic to see if you've remembered everything!
https://quizlet.com/_9rwjxe?x=1jqt&i=2kfojh

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Il existe différents modes de production industrielle du dihydrogène. Cette fiche explique ces différents processus et leur mode de fonctionnement.

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Le stockage de l’hydrogène consiste en toutes les formes de mise en réserve du dihydrogène en vue de sa mise à disposition ultérieure comme produit chimique ou vecteur énergétique. Plusieurs types de stockages existent et cette fiche vous les détaille.

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Une fois produit, le dihydrogène peu servir dans de nombreux domaines et être ainsi valorisé. Cette fiche rassemble les différents usages recensés du dihydrogène en tant que vecteur énergétique.