What is green hydrogen?
Green hydrogen refers to the splitting of water into hydrogen and oxygen via electrolysis in an electrolyzer. If renewable electricity is used to power the electrolyzer then the hydrogen produced can be referred to as green hydrogen. Powered by renewable energy sources such as solar PV or offshore wind power, this green hydrogen will have lower carbon emissions associated with it than the hydrogen being produced today, most of which comes from steam methane reformation or coal gasification. A plethora of colours now exist to describe the various sub-routes to hydrogen production. For example, pink/purple hydrogen is used to describe electrolytic hydrogen using nuclear power and yellow hydrogen describes electrolytic hydrogen utilising mixed power grid sources, though it has also been used to refer to solar PV powered water electrolysis. Grey and black hydrogen refer to hydrogen produced via methane reformation or coal gasification while blue hydrogen describes this hydrogen if the resulting CO2 emissions are captured.
Green hydrogen markets
Green hydrogen offers a route to decarbonising hydrogen production, in turn helping to decarbonise various hard-to-abate sectors. Currently, the primary end-uses for hydrogen are in refining activities and ammonia production. These are forecast to remain the key uses for hydrogen in the medium-term. Furthermore, hydrogen can also play a role in helping to decarbonise hard-to-abate sectors such as steel manufacturing, methanol production or certain modes of transport such as heavy-duty vehicles, shipping, or aviation. Beyond decarbonization, hydrogen also offers a route to greater energy security by allowing local production of hydrogen as well as a reduction in the use, via their replacement, of natural gas and coal for industries including steel, methanol, construction and chemicals production. This is particularly topical given the uncertainty and volatility in natural gas prices and supply following Russia’s invasion of Ukraine in 2022 as well as growing demand and pressure to decarbonise the global economy. However, IDTechEx estimate that green hydrogen accounts for <1% of total hydrogen production globally in 2022, highlighting the level that is needed in the electrolyzer and green hydrogen market.
There are three main types of electrolyzer technology that can be used to produce green hydrogen: alkaline (AEL or AWE), proton-exchange-membrane or polymer-electrolyte-membrane (PEM), and solid-oxide electrolyzers (SOEL). Each technology comes with their own set of advantages and disadvantages. Alkaline electrolyzers have long been commercial and used for industrial applications. They are characterised by their low capital costs and long lifetimes. PEM electrolyzers are at an earlier stage of commercialization but are set to gain market share over the coming years. They are characterised by higher power densities, output hydrogen pressures and faster response times than alkaline systems. This generally makes them better suited to utilising renewable power. SOELs are the youngest electrolyzer technology. Operating at elevated temperatures above 700°C, they offer higher system efficiencies but are expensive, can struggle with dynamic operation, and improvements to system lifetime are likely to be necessary. Nevertheless, their higher efficiencies can play a role in decreasing the levelized cost of the hydrogen produced while they also hold promise for producing syngas through the combined electrolysis of H2O and CO2.
Key metrics for assessing the performance of an electrolyzer system include: efficiency, capital cost, response time and dynamic range, hydrogen purity and pressure, lifetime and footprint. Ultimately, one of the most important parameters is likely to be levelized cost of hydrogen. This report provides an analysis and comparison of the different electrolyzer systems available, covering working mechanisms, materials employed, and system performance, amongst other factors. An outlook and discussion on future electrolyzer technology adoption is also provided alongside improvements and innovations being made to electrolyzer technology.
Manufacturing capacity is expected to increase significantly over the next 5 years as players looks to capture a share of this growing market. IDTechEx analysis shows that European companies are particularly active in their plans to expand and grow their electrolyzer manufacturing capacities and capabilities, though significant investment into electrolyzer manufacturing is also expected from Chinese and US companies while Indian and Australian players are also looking to enter the market. The electrolyzer market is currently dominated by alkaline and PEM electrolyzer manufacturers with comparatively few companies manufacturing or commercialising solid-oxide electrolyzers. However, the similarity between solid-oxide electrolyzers and solid-oxide fuel cells could provide an entry point for fuel cell manufacturers into the green hydrogen market. Certainly, growth in the electrolyzer market, across the three electrolyzer types, will be needed to meet ambitious national and regional targets for green and clean hydrogen production.
This report provides analysis and comparison of the electrolyzer technologies and designs being commercialised and developed. In addition, an overview of the market is provided, outlining key electrolyzer manufacturers and players, current manufacturing capacities, planned installations and regional green hydrogen production targets.