Questions from concerned citizens about energy, hydrogen and fuel cells
answered by 
Vol. 4: From alternatives for H2 production to a short animation how a fuel cell works

Here you find answers to questions from concerned citizens
about sustainability, hydrogen and fuel cells. You are most welcome to
send in your own set of energy related questions.

13) What is your opinion of alternatives like nuclear and biomass for H2
production in the mean term?

Various projects have been initiated for hydrogen production from nuclear
energy and biomass over centuries. It is obvious that H2 production from
nuclear energy (via electrolyzer or nuclear-thermal energy) has no environmental
advantages whatsoever and thus is not to be considered as an alternative
method of hydrogen production. With biomass it is a bit different, though.
H2 can be produced via pyrolysis (thermochemical conversion) or anaerobic
digestion (fermentation) of biomass resources. Seen from my perspective,
the technology is still in an early stage of development and capable of
supplying only small amounts of hydrogen to feed worldwide energy demands.
As long as we use our “biomass waste” as energy source for hydrogen production
I see no contradiction in terms of our environment. But we should avoid using
biomass specifically grown for energy uses as it destructs our landscape and
increases the price of our food.

14) Have you explore the alternative for H2 production from the space?

Not yet. One day it might be possible to mine Jupiter which is made out of
90 percent hydrogen or even harvest our sun more directly. But first of all we
should start thinking about adequate methods to produce hydrogen here on Earth.
The sooner, the better.

15) What application do you suggest for oil usage in a sustainable manner?

First of all we should stop using oil to fulfill our energy needs or to burn it to run our cars.
It is far too precious to spoil it in this way. New ideas and plans for a more sustainable
energy generation and supply chain are already
existing, so why not using them? All fossil fuel resources - be it oil, gas or
even coal - should be kept for future generations (in 100 years from now
we might know better, more economical ways to use and handle the fossil feedstock)
or for material production and medicine.

16) What renewable energy storage systems do you see in the future?

The conventional way to store electricity is in hydro dams, used successful
since many years. Big new installations are made in China and Brazil. To store
hydrogen environmental benign and ecological, additional scientific work is needed:
Currently used pressurized containers are not particularly energy dense and a
bit bulky to be used, e.g. as tanks in vehicles. Some metal hydrides absorb hydrogen
when exposed to the pressurized gas. Once they are heated or compressed,
the hydrogen is released. But the weight of the metals makes this storage system
quite heavy. In my opinion, the most profitable approach will come from nanoscale
engineering. Due to the large surface areas with relatively
small mass, some nanosize structures have the potential for high capacity
hydrogen storage. Theoretically, every atom within a nanotube could hold
on to one hydrogen atom until needed.

17)  Is there any idea about the recycle rate of the H2 storage systems?

Based on my research, there is currently no company working on this problem.
Still, it has to be coped with.

18) Do you have any didactical simulation of how FC's works?

A short animation and explanation how a fuel cell works can be found here: