Green Hydrogen – Place Your Bets

H2 Electrolysis

As we have seen from an earlier blog if we are going to meet our 2050 targets, we are going to need to realise a vast increase in green hydrogen (from renewable energy sources). As a result, we are seeing a ramp-up in investment and research going into the development of more efficient techniques for generating green H2. Although the concept of electrolysis is far from new (having first been demonstrated in 1801 by William Nicholson and Anthony Carlisle in England) it remains a very open race as to which approach will ultimately prove to dominate the market.

Alkaline and PEM

The primary techniques in use today are alkaline and PEM electrolysis. The original and more common alkaline technique, in industrial use since the 1920s, uses alkaline water and an electrolyte (such as potassium hydroxide) separated by a membrane. The system is well understood and stable and offers a long lifespan of operation. The newer PEM (Proton Exchange Membrane) method is generally considered to be more efficient and is gaining share in the market with companies such as ITM Power expanding rapidly as demand accelerates. However, for the long-term efficient production of green hydrogen both systems have their drawbacks. For the alkaline method this is the cold start up-time which is longer than the PEM system making it less effective at capturing changes in availability of renewable energy as grid demand and weather changes during the day. PEM, on the other hand uses expensive and rare earth minerals in a highly caustic environment making them a questionable long-term solution.

New Kids on the Block

Clearly much R&D is going into removing these obstacles, and there are regular breakthroughs in labs around the world, and PEM and alkaline are far from the only games in town. Other technologies such as solid oxide electrolysis (SOE) and cryogenic separation are nipping at their heels. One fascinating Irish company, CPH2, now based in Doncaster, has developed an alternative, membrane free technique which does not require expensive or rare minerals and produces very pure hydrogen. They recently partnered with Octopus Energy to build a 1MW membrane-free electrolysis project serving the transport and industrial sectors. As the investment in green hydrogen production goes exponential over the coming decades to 2050 companies like CPH2 are very well positioned to capitalise on the opportunity.