Michael

Here are my arguments again: We all want to establish an energy future based on clean renewables. Most of these are harvested as electricity. Electricity can be distributed to users by wire with highest efficiency. Why then suggest converting electricity into hydrogen, have all the energy losses of hydrogen packaging and transport, transfer and storage before converting it back to electricity. Depending on the chosen path, only 20 to 30% of the original AC power can be put back to useful AC power behind a fuel cell.
Unfortunately, the “Hydrogen Initiative” of President Bush was announced before scientist were able to go through the energy analysis of the hydrogen chain and identify the scheme as one of the most absurd suggestions for solving the energy problem.

We need energy from renewable sources to meet the energy demand of the future. But lasting solutions demand that renewable energy technologies are considered with a high EROI (energy returned on energy invested). Depending on site wind power produces up to 100 times more energy than invested in the installation, PV has reached a ratio of 10 while biomass farming is at +/- one.

Some governments of the cited countries have already changed their views on hydrogen. It is time for DOE to focus on the support of the energy harvest from renewable sources before spending more money on energy carriers. Unfortunately, scientists of all levels are urged by their institutions to bring in research grants. As long as public money is abundantly available critical views are not welcome.

Fortunately, I cannot be accused to present biased views, because I am totally independent and refuse to accept funding for any one of the players in the field. My income does not depend on my position to the hydrogen economy. No wonder, people receiving salaries for working on hydrogen do not like my views.

Ulf Bossel

Personally, I think there MAY be a subsidiary role for hydrogen when we have, many decades from now, an abundance or superabundance of renewable electricity available. The emphasis NOW on hydrogen has the net effect of a stalling tactic and has been used as a way to quash the development of direct-electric solutions (Calfornia CARB 1997-2005). There are powerful interests with which you appear to be aligning yourself, interests that have not shown the guts or foresight to take a leading role in the efforts to build a climate-friendly civilization.

If we had many decades to figure out the climate crisis, it might make sense to take hydrogen more seriously. Climate scientists and satellite observations of the ice packs at the poles indicate that we probably don’t have that luxury. Therefore, I would suggest that you re-orient your focus on the renewable electricity that you agree is more efficient than the detour of generating hydrogen. Why not do the right thing from an engineering AND a moral standpoint?

Michael

I agree – your engineering analysis is very complete and thorough.

My questions for you are: Did you start this analysis with the result in mind? Which assumptions in your own analysis would you consider assumptions on the margin? Which numbers did you choose deliberately to make your case?

I know from my own laboratory research and field experience that some of your analysis is incorrect. I would like to know which parts you think may be incorrect.

For instance, currently tube trailers used for transportation hydrogen (in the US) operate at 50MPa, not 20MPa as you claim, for a >2x volumetric energy density than your analysis shows.

Your electrolyzer voltages and efficiencies do not include recent developments in catalysts, PEM stack electrolyzers, high pressure electrolyzers, and direct compression (pump stack) electrolyzers.

Your automobile fuel cell efficiencies do not include pressurizing the fuel cell stack to above atmospheric pressure (the parasitic losses from the compressor are smaller than the efficiency gain of the stack).

You pick numbers for pipelines as same-as-methane flow rates for pipelines rather than optimally size systems for hydrogen.

You do not consider the much higher efficiency chains of biomass gassification (with steam shift) to hydrogen. If you consider gassification of woody biomass to hydrogen vs fermenting to ethanol vs burning for heat (for electricity), you will find the hydrogen chain to be highly efficient, even with your transport losses.

You do not consider the use of industrial waste hydrogen (from chlorine manufacturing and coke oven gas among other processes) that can be utilized for transportation purposes.

There are other items as well…

I completely agree with you that hydrogen is more difficult than liquid hydrocarbons to transport. No argument. That is why so many engineers and scientists are working on mitigating the difficulties. You say it’s a fool’s errand, but it is a fool’s errand to maintain the status quo.

What hydrogen does enable is generation of a fuel from feedstocks that are not currently used for industrial or vehicle fuel – petroleum coke, biomass, landfill gas, stranded renewables, off-peak renewables, and many others. It enables generation of electricity without the inefficient chemical-to-thermal-to-mechanical energy step. It enables transportation solutions with long range, low weight, convenient refueling, and zero point of use pollution (which is extremely important, even moreso than pure efficiency in many people’s minds). Pure renewable electricity and biofuels don’t address these issues.

Will pure renewable electricity have a role in the transportatin future? Of course! This is clearly the lowest CO2, highest efficiency route. But it won’t work for all of our needs.

Will there be chemical synthesis of hydrocarbons from biomass and hydrogen? Probably – it only makes sense.

But hydrogen enables these as well, and your strict boundaries of consideration in your papers blurr the overall positive environmental and energy sustainability impacts of developing hydrogen as a transportation fuel.

That is why your analysis are at odds with those of the US DOE, Natural Resources Canada, EU, Germany, Japan, and others, who have taken wider boundaries into account when perfoming analysis on and deciding to fund research and development of a hydrogen economy.

I appreciate that you are deeply passionate, extremely knowledgable, and engaged in the world of energy engineering. But I do find your analyses to be in contrast with my own experience, and the experience of my colleagues today in the field.

Thank you,

James

To illustrate the usefulness of our presentation we have applied the results to four typical hydrogen process chains. Mr. Maxwell has picked his numbers from one or the other of the four illustrative hydrogen process chains. However, the general conclusion of our study is not challenged or changed by such selective interpretation. There is no possibility to generate, package, distribute and convert hydrogen is such manner that more than 25 to 30% of the original energy can be recovered. A hydrogen economy is a wasteful scheme, in particular, as hydrogen has to be made mainly from renewable electricity or other sources of energy in a sustainable future. As electricity can be much better distributed by wires, Hydrogen has to compete with its own energy source, a task difficult to accomplish. Physics is not be changed by quoting embellished efficiencies of fuel cells or refers numbers of yesterday’s batteries.

In summary, a sustainably organized energy future must be based on energy from renewable sources coupled with the highest efficiency from source to service. An “electron economy” can satisfy these criteria much, much better than a “hydrogen economy”. Fortunately, the World finally realizes that hydrogen is not the solution. Hydrogen is only an energy carrier like buckets are used to carry water. Only fools would suggest to distribute buckets as a solution for the water problems in dry Africa. It is time to end the hydrogen dreams.

Ulf Bossel

Be careful what you believe in Mr. Bossel’s writings – he deliberately picks numbers for efficiency etc that skew his results to favour electricity over hydrogen, especially for transportation solutions. As well, he bases a lot of his writings on the state of the hydrogen and fuel cell industry in the 1980′s and early 1990′s, and has not kept up with more recent developments.

He says that electricity is 4x as efficient as hydrogen? Not true. 1.5x I will believe, but only if you are talking about pure electrons generated through renewables, and as attractive as that solution is, it won’t work everywhere, all of the time. For the remainder, we need hydrogen.

For instance, he deliberately shows liquifaction of hydrogen in his energy chain, when transporting gaseous hydrogen by pipeline or tube trailer is much much more efficient, and is being done in practice today. Yes, there is market need for liquified hydrogen, and that is being produced, but the vast majority of it is not used for transportation but industrial uses.

And in his energy chains, he does not show charging (86%) and discharging (86% again) for an EV battery. He also does not include self discharge effects of batteries. If you charge an EV battery to 100% SOC and let the vehicle sit for a week, it will be down to about 95% SOC. So what percentage of the time are people actually driving their EV? Maybe 5% of a day. So there should be a 5% self discharge factor for batteries in his chain. But he chooses not to include that.

As well, he shows fuel cell efficiency at 40%, with vehicle losses adding another 15% to 20%. This is not true today. Entire fuel cell vehicles (tank to wheels) show efficiencies up to 60% (Honda, Daimler, GM, as published by NREL and each automaker).

Furthermore, generation of hydrogen by renewables will increase the overall efficiency of the grid by leveraging the stranded and off-peak renewable generation, and reducing the need to keep fossil plants spinning in case the renewables go offline (wind dies down sometimes). In the US, fossil plants are kept running in case they are needed, and that is hugely inefficient. Mr. Bossel does not consider these points of view.

There are many problems with Mr. Bossel’s papers, and these are only a couple of them. There is a reason why his papers do not get cited in respectable scientific journals, and only on various weblogs, and that reason is that they are not academically honest.

I’m looking forward to both hydrogen and electricity being part of the transportion and industrial energy mix, and I think we’ll all be much better off for it. But we all need to be academically honest when discussing how best to achieve these goals.

Thanks,

James