In my opinion the hydrogen technology is surpassed by the redox flow technology which is much simpler, more secure (no explosion risks, not needing a totally sensor-controlled leakage system as asked by international safety and standard organizations). With respect to the electrochemical kinetics heterogeneous charge transfer reactions are more problematic than those of dissolved redox couples. The invention of the research group at the MIT should not be disregarded by lobbying for a technology which has its limit (storage, transportation, distribution all need totally novel developments). In this respect the so-called “Cambridge-Crude” (http://www.gizmag.com/semi-solid-flow-battery-design/18907/) could immediately replace gasoline or Diesel in the tanks after a cleaning. All gas-stations would no longer need a refueling since they recharge the “Cambridge-Crude” high energy redox electrolyte by renewable electrical energy. No gasoline trucks will be needed in the future if a balance is established between used redox-electrolyte taken from the costumers and the re-charged system at the gas station.

The future of our energy needs will certainly be dominated by redox-flow batteries within the next 10 years. The vanadium type ones will be used for larger storage duties (grids with > 1 megawatt) and the new lithium-based developed at the MIT will be used in cars. To use two different oxidation states of a redox-species which can be reversible oxidized resp. reduced delivering electrical energy is much simpler than to use the potentially explosive hydrogen technology. In both cases the energy carrying redox-system is never consumed or wasted. Charging of the redox-electrolyte energy carrier can be based on green energy (photovoltaic, wind, etc.). Such redox electrolytes can be used as recyclable “gasoline” being bought – charged-up - at special stations or re-charged at home over night in the garage.

Gadre, in Europe and especially in Germany, the large-scale storage of intermittent renewable energy (e.g. wind, solar) is of huge interest. Considering automotive and such energy-storage applications, the attached link might be of interest to you.

Article Fuel cell electric vehicles and hydrogen infrastructure: Status 2012

In my opinion the hydrogen technology is surpassed by the redox flow technology which is much simpler, more secure (no explosion risks, not needing a totally sensor-controlled leakage system as asked by international safety and standard organizations). With respect to the electrochemical kinetics heterogeneous charge transfer reactions are more problematic than those of dissolved redox couples. The invention of the research group at the MIT should not be disregarded by lobbying for a technology which has its limit (storage, transportation, distribution all need totally novel developments). In this respect the so-called “Cambridge-Crude” (http://www.gizmag.com/semi-solid-flow-battery-design/18907/) could immediately replace gasoline or Diesel in the tanks after a cleaning. All gas-stations would no longer need a refueling since they recharge the “Cambridge-Crude” high energy redox electrolyte by renewable electrical energy. No gasoline trucks will be needed in the future if a balance is established between used redox-electrolyte taken from the costumers and the re-charged system at the gas station.

This is the great thing about science. There is a challenge and there are of course many different opinions how to solve the problems. It is extremely difficult to pick a winner during the development process, especially when comparing technologies at very different maturity levels (i.e., a fully engineered solution vs. a breakthrough/discovery in the lab). Especially in the energy sciences, the road from invention to application is very long and tough.

But finally, there is a specific set of metrics to determine in the end who was right.

In the case of large-scale energy storage, these are, inter alia, energy density on a systems level, round-trip efficiency, cost (both investment & operating cost) and reliability/durability.

Regarding large-scale storage of energy, hydrogen, synthetic chemical energy carriers (synthesized from H2, CO2 and/or biomass, e.g. synthetic methane) and various types of batteries (Sodium-Sulfur, Lithium-based, Redox-Flow ...) are the competitors.

Let's work hard and see what the future will bring ...

Thank you Dr Cammann, Dr Eberle for the interesting answers ! Research of "Cambridge Crude" as well as advances by companies like General Motors look very promising !

In terms of government policies, I read about UK H2 mobility programme where they aim to bring in FCEVs on roads by 2020 or so. This may shape the landscape of future devices.

Do you think similar steps are being taken in other countries as well? How big do you think is the "government policy factor" in the next technology?

For those who show interest in our energetic future, attached the paper I found most interesting in Adv. Energy Mater. 2011, XX, 1–6; as an electrochemists which strong interest in electrochemical kinetics and as a strong supporter of the German “Energiewende” I will predict a successful future of the redox-flow idea as long as a fair technological competition will arise. The MIT approach has already being patented with very strong claims and the vanadium based approach (developed since over 20 years in Australia) is already commercially available in Germany (http://de.cellcube.com/en/index.htm)!

I forget to pay tribute to Professor Maria Skyllas-Kazacos who can be named “mother of the vanadium-based redox-flow batteries” for her outstanding research on this topic leading to functioning prototypes also concerning their practicability. In the attached youtube video she explains the principle.

http://www.youtube.com/watch?v=hD3rL4NjXVE

Gadre, when interested in large-scale cooperation programs between industry and the public sector on emerging technologies, the example of the National Platform E-Mobility in Germany might be of interest to you.

I attach a link to an interesting recent document - by a German government agency - regarding these activities. The entire value chain is addressed, as well as the entire development process from academia to industry.

http://www.gtai.de/GTAI/Navigation/EN/Invest/Service/publications,did=781756.html