Hydrogen Dreams or are they ?

Hi Helios,

Happy to to see some discussion about hydrogen on the IET forums, especially with the research you put into quantifying the scale of the task that is faced. Part of my day job is to try and make these numbers work for fuel cells. Happy to answer specific questions (with data!) about fuel cells if curious, particularly their applicability to different applications (stationary, automotive, rail, maritime and others) as things currently stand.

A couple of points to try and build on the discussion below. Forgive me if they are a bit clichéd (or wander off topic a little), they are all well trodden points to make.

More or less regardless of scale and technology, skipping the thermal stage in going from fuel to electricity means better efficiency. Fuel cells are not beholden to the Carnot limit. 83% is our theoretical limit when reacting hydrogen with oxygen to produce water. In practice, we can match and exceed combined cycle turbines even at household scales and there is still room for improvement. Even “omnivorous” high temperature fuel cells operating off of fossil fuels reduce emissions from generation significantly, simply due to getting more electricity out of the same fuel, whilst also generating no particulate, NOx or SOx air pollutants. Speaking of which:

"The estimated annual economic costs of the above health impacts for PM2.5 was £1.4 billion, up to £2.3 billion for NO2, and up to £3.7 billion for both pollutants.”. [Page 328, “Economic evidence base for London 2016” https://www.london.gov.uk/sites/default/files/chapter7-economic-evidence-base-2016.pdf, which is itself citing a study from Kings College London: Walton, H. et al, (2015) “Understanding the Health Impacts of Air Pollution in London”, King’s College London for GLA and TfL.]

Quantifying these kinds of differences between incumbent technologies and “sustainable” replacements is difficult, and harder still to persuade people of their relevance to an economic discussion. Factoring in even just the ones we can quantify greatly strengthens the economic arguments for post-combustion technologies like fuel cells.

There is plenty of ongoing work to try and do this in an accessible and consistent way, which is something that you might also be interested in. To me it seems you have a good eye for getting hold of the obscure data and presenting it clearly!

My view is that the best thing to do with any renewable electricity generation right now is to avoid converting it into other forms and use it directly, with the aim of shutting off as many of the oldest polluting power plants for good as we can. We’ve got a very big task on our hands to get to the stage where we have enough renewable generation to store significant amounts in hydrogen because to electrolyse you need clean (ish) water.

Unfortunately fresh water is in increasingly short supply in many parts of the world (including the aquifers which support London), which looks set to get worse in the coming decades. So we need to add desalination of sea water, presently another energy intensive process, before getting stuck into the numbers you posted about electrolysis, storage and fuel cells. So add the renewable energy for this on top too. Or should we use the water to drink, or for agriculture? It’s all together an urgent global conundrum.

Encouragingly we are winning increasingly more customers from all over the world with the varied benefits of fuel cell technology. We see international collaboration as vital for the transition away from fossil fuels and are very active in promoting cooperation wherever we can.

As a miniscule part of the bigger picture, I must end my piece here by showing my support for everyone generating as much renewable power as they can, whilst reducing our collective energy footprints as much as reasonably possible without unacceptable losses in quality of life (easier said than done!). In my opinion these are the most helpful things we can do in enabling a sustainable future and bringing hydrogen dreams to life, both yours and mine.

Thanks for your time and for reading!

All the best,

Joe

Hi Helios,

Happy to to see some discussion about hydrogen on the IET forums, especially with the research you put into quantifying the scale of the task that is faced. Part of my day job is to try and make these numbers work for fuel cells. Happy to answer specific questions (with data!) about fuel cells if curious, particularly their applicability to different applications (stationary, automotive, rail, maritime and others) as things currently stand.

A couple of points to try and build on the discussion below. Forgive me if they are a bit clichéd (or wander off topic a little), they are all well trodden points to make.

More or less regardless of scale and technology, skipping the thermal stage in going from fuel to electricity means better efficiency. Fuel cells are not beholden to the Carnot limit. 83% is our theoretical limit when reacting hydrogen with oxygen to produce water. In practice, we can match and exceed combined cycle turbines even at household scales and there is still room for improvement. Even “omnivorous” high temperature fuel cells operating off of fossil fuels reduce emissions from generation significantly, simply due to getting more electricity out of the same fuel, whilst also generating no particulate, NOx or SOx air pollutants. Speaking of which:

"The estimated annual economic costs of the above health impacts for PM2.5 was £1.4 billion, up to £2.3 billion for NO2, and up to £3.7 billion for both pollutants.”. [Page 328, “Economic evidence base for London 2016” https://www.london.gov.uk/sites/default/files/chapter7-economic-evidence-base-2016.pdf, which is itself citing a study from Kings College London: Walton, H. et al, (2015) “Understanding the Health Impacts of Air Pollution in London”, King’s College London for GLA and TfL.]

Quantifying these kinds of differences between incumbent technologies and “sustainable” replacements is difficult, and harder still to persuade people of their relevance to an economic discussion. Factoring in even just the ones we can quantify greatly strengthens the economic arguments for post-combustion technologies like fuel cells.

There is plenty of ongoing work to try and do this in an accessible and consistent way, which is something that you might also be interested in. To me it seems you have a good eye for getting hold of the obscure data and presenting it clearly!

My view is that the best thing to do with any renewable electricity generation right now is to avoid converting it into other forms and use it directly, with the aim of shutting off as many of the oldest polluting power plants for good as we can. We’ve got a very big task on our hands to get to the stage where we have enough renewable generation to store significant amounts in hydrogen because to electrolyse you need clean (ish) water.

Unfortunately fresh water is in increasingly short supply in many parts of the world (including the aquifers which support London), which looks set to get worse in the coming decades. So we need to add desalination of sea water, presently another energy intensive process, before getting stuck into the numbers you posted about electrolysis, storage and fuel cells. So add the renewable energy for this on top too. Or should we use the water to drink, or for agriculture? It’s all together an urgent global conundrum.

Encouragingly we are winning increasingly more customers from all over the world with the varied benefits of fuel cell technology. We see international collaboration as vital for the transition away from fossil fuels and are very active in promoting cooperation wherever we can.

As a miniscule part of the bigger picture, I must end my piece here by showing my support for everyone generating as much renewable power as they can, whilst reducing our collective energy footprints as much as reasonably possible without unacceptable losses in quality of life (easier said than done!). In my opinion these are the most helpful things we can do in enabling a sustainable future and bringing hydrogen dreams to life, both yours and mine.

Thanks for your time and for reading!

All the best,

Joe