Historical analysis of FCH 2 JU electrolyser projects : evaluation of contributions towards advancing the state of the art.
Date: 2021-04-14
Institutions: Joint Research Centre
Subjects: EU research policy, European Joint Undertaking, electrical process, performance measurement, research programme, research project, research report

Historical Analysis of FCH 2 JU 
Electrolyser Projects 

Evaluation of contributions 
towards advancing the State 
of the Art. 

Davies, J. 

Dolci, F. 

Weidner, E. 

2021  

EUR 30648 EN 

 
 
This publication is a Technical report by the Joint Research Centre (JRC), the European Commission’s science and knowledge service. It 
aims to provide evidence-based scientific support to the European policymaking process. The scientific output expressed does not imply a 
policy position of the European Commission. Neither the European Commission nor any person acting on behalf of the Commission is 
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of the European Union concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation 
of its frontiers or boundaries. 

Contact information  
Name: Jonathan Davies 
Email: jonathan.davies@ec.europa.eu 

EU Science Hub 
https://ec.europa.eu/jrc 

JRC121704 

EUR 30648 EN 

PDF 

ISBN 978-92-76-32441-6 

ISSN 1831-9424 

doi:10.2760/951902 

Luxembourg: Publications Office of the European Union, 2021  

© European Union, 2021  

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How to cite this report: Davies, J., Dolci, F. and Weidner, E., Historical Analysis of FCH 2 JU Electrolyser Projects: Evaluation of contributions 
towards advancing the State of the Art, EUR 30648 EN, Publications Office of the European Commission, Luxembourg, 2021, ISBN 978-
92-76-32441-6, doi:10.2760/951902, JRC121704 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Contents 

Acknowledgements .......................................................................................................................................................................................................................................... 1 

Abstract ....................................................................................................................................................................................................................................................................... 2 

1 

Introduction..................................................................................................................................................................................................................................................... 3 

2  Methodology of Historical Project Review ......................................................................................................................................................................... 4 

3  FCH 2 JU Electrolyser Projects ..................................................................................................................................................................................................... 5 

4  Electrolyser Technologies .................................................................................................................................................................................................................. 7 

4.1  Alkaline Electrolyser .................................................................................................................................................................................................................. 7 

4.1.1  Operating Principles ................................................................................................................................................................................................ 7 

4.1.2 

State of the Art ........................................................................................................................................................................................................... 7 

4.1.3 

Applications ..................................................................................................................................................................................................................... 8 

4.1.4 

Progress of the Programme against Targets for Key Performance Indicators (KPIs) ............................ 9 

4.2  PEM Electrolyser ........................................................................................................................................................................................................................ 15 

4.2.1  Operating Principles ............................................................................................................................................................................................. 15 

4.2.2 

State of the Art ........................................................................................................................................................................................................ 15 

4.2.3 

Applications .................................................................................................................................................................................................................. 16 

4.2.4 

Progress of the Programme against Targets for Key Performance Indicators (KPIs) ......................... 17 

4.3  Solid Oxide Electrolyser ...................................................................................................................................................................................................... 25 

4.3.1  Operating Principles ............................................................................................................................................................................................. 25 

4.3.2 

State of the Art ........................................................................................................................................................................................................ 25 

4.3.3 

Applications .................................................................................................................................................................................................................. 26 

4.3.4 

Progress of the Programme against Targets for Key Performance Indicators (KPIs) ......................... 26 

4.4  Protonic Ceramic Electrolyser ....................................................................................................................................................................................... 33 

4.4.1  Operating Principles ............................................................................................................................................................................................. 33 

4.4.2 

State of the Art ........................................................................................................................................................................................................ 33 

4.4.3 

Applications .................................................................................................................................................................................................................. 34 

4.4.4 

Key Performance Indicators (KPIs) and Targets ....................................................................................................................... 34 

4.4.5 

Progress against State of the Art - PCEL ........................................................................................................................................ 34 

5  Literature and Patenting Trends in Electrolyser Technologies ................................................................................................................... 35 

5.1  Literature and Patent Searching Methodologies ........................................................................................................................................ 35 

5.2  Patent data trends based on the CPC Classification .............................................................................................................................. 37 

5.3  Literature and Patenting Visualisations using TIM ................................................................................................................................... 40 

6  Conclusions and Recommendations .................................................................................................................................................................................... 44 

i 

 
 
 
References ............................................................................................................................................................................................................................................................. 46 

List of abbreviations and definitions ........................................................................................................................................................................................... 48 

List of figures ..................................................................................................................................................................................................................................................... 50 

List of tables ........................................................................................................................................................................................................................................................ 51 

Annexes: Summary of Projects reviewed for this Report ......................................................................................................................................... 52 

ii 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Acknowledgements 

The  authors  would  like  to  thank  Mirela  Atanasiu,  Eleni  Zafeiratou,  Nikolaos  Lymperopoulos,  Dimitra  Dirmiki, 
Kostis Sakellaris and Pierre Michel of the Programme Office of the Fuel Cell and Hydrogen Joint Undertaking 
for useful discussions and reviewing of this report. Furthermore, we would like to thank Marc Steen for a critical 
reading of the manuscript. 

We would also like to thank Aliki Georgakaki and Francesco Pasimeni of the JRC Petten Knowledge Management 
unit (C.7) for their assistance with the Patent section of this work (specifically providing the data from which 
the plots are created). Thank you to Sotiris Fragkiskos (JRC I.3) for his help regarding the plots prepared using 
Tools for Innovation Monitoring (TIM). 

Authors 

Jonathan Davies, Francesco Dolci and Eveline Weidner. 

1 

 
 
 
 
 
Abstract 

As a part of the knowledge management activities of the Fuel Cell and Hydrogen Joint Undertaking, the JRC has 
been commissioned to perform a series of historical analyses by topic area in order to assess the impact of 
funded projects and the progression of the FCH JU Multi-Annual Work Plan (MAWP) towards its objectives. 

This report considers the performance of projects against the overall Programme Targets for electrolysers, using 
Key Performance Indicators (KPI) for assessment. The purpose of this exercise is to see whether and how the 
programme has enhanced the state of the art for electrolysers and to identify potential Research and Innovation 
gaps for the future. 

The programme generally addresses three main electrolyser types – Alkaline, PEM and Solid Oxide. Therefore, 
projects addressing these electrolyser types were identified, and values for the achieved KPIs extracted from 
relevant  sources  of  information  such  as  final  reports  and  the  TRUST  database.  As  much  of  this  data  is 
confidential, a broad analysis of performance of the programme against its KPIs has been performed, without 
disclosing confidential information. The results of this analysis are summarised within this report. 

The information obtained from this study has then been used to suggest future modifications to the research 
programme and associated targets.  

2 

 
 
 
 
1 

Introduction 

The  Fuel  Cell  and  Hydrogen  Joint  Undertaking  (FCH  JU)  was  established  according  to  a  European  Council 
Regulation  of  30th  May  2008  as  a  public/private  partnership  between  the  European  Commission,  European 
Industry and Research Organisations [1].  The FCH JU has provided EU funding for projects related to fuel cells 
and hydrogen, first under Framework Program 7 (FP7) from 2008-2013 and, as the Fuel Cell and Hydrogen 
Joint Undertaking 2 (FCH 2 JU), under the Horizon 2020 Program (H2020) from 2014 onwards. At the time of 
the analysis, 246 projects had been funded, with the goal of accelerating fuel cell and hydrogen technologies 
to the marketplace, hereby assisting in the transition to a carbon-clean energy system.  

As part of the FCH 2 JU’s knowledge management activities, a series of historical analyses by topic area has 
been commissioned, to review the impact of the funded projects and the progression of the programme towards 
its targets.  A detailed confidential report has been prepared for the FCH 2 JU including analysis of confidential 
data. This public document is a summary of the outcomes reported in the confidential document. 

Funding from the FCH 2 JU is distributed according to two main pillars, Energy and Transport, as identified in 
the Multi-Annual Work Plan (MAWP)  [2].  In addition, there are cross-cutting activities which perform  general 
activities relevant to both main pillars (for example educational or safety-related work). Furthermore, there are 
projects that are deemed "over-arching" because they are relevant to both Energy and Transport and therefore 
receive part of their funding from each pillar. Ongoing projects funded by the FCH 2 JU are assessed each year 
as part of the Programme Review. This is carried out by a team of experts at the JRC who assess the project 
portfolio against key objectives of the programme. For the purpose of the Programme Review, the projects are 
split across six panels, which look at specific areas of Fuel Cell and Hydrogen (FCH) development. The Pillars 
and Panels are defined in Table 1.  

This  report  considers  the  quantitative  performance  of  projects  against  the  overall  Programme  Targets  for 
electrolyser Key Performance Indicators (KPI). The purpose of this exercise is to see how the programme has 
enhanced the state of the art for electrolysers and to identify potential R&I gaps to be covered in the future. 

Table 1: Programme Review Day Panels – Names and Topics 

Pillar/Activity  Panel Name 

Topics 

Transport 

1 - Trials and Deployment of 
Fuel Cell Applications 

Projects targeting the demonstration and proof of concept 
(PoC) of FCH applications in the transportation pillar 

2  -  Next  Generation  of 
Products 

Basic  and  applied  research  projects  tackling  subjects 
related to the transportation pillar 

Energy 

3 - Trials and Deployment of 
Fuel Cell Applications 

Projects  targeting  the  demonstration  and  PoC  of  FCH 
stationary heat and power applications in the energy pillar 

4  -  Next  Generation  of 
Products 

Basic  and  applied  research  projects  tackling  subjects 
related to FCH stationary heat and power applications 

5  -  Hydrogen  for  Sectorial 
Integration 

All projects addressing hydrogen production, distribution 
and storage issues 

Cross-cutting 

6 - Support for Market Uptake  Projects addressing cross-cutting issues 

Source: JRC based on information from the FCH JU, 2020. 

3 

 
 
 
 
 
 
 
 
 
2  Methodology of Historical Project Review 

The purpose of this historical project review is to determine whether and how FCH (2) JU projects have played 
a role in advancing the state of the art in the field of electrolysers. In particular, the main aim was to use key 
performance  indicators  (KPIs)  for  the  different  electrolyser  technologies  to  show  how  funded  projects  have 
performed against the State of the Art (SoA) and overall Programme Targets.  In order to perform this task, the 
following steps were undertaken.   

Firstly, the projects involving electrolysers were identified through a database which has been developed for 
the purpose of classifying all FCH JU and FCH 2 JU projects according to keywords [3]. The majority of these 
projects are those that have been specifically targeting the improvement in the performance of electrolysers 
for the production of hydrogen within Panel 5 of the FCH 2 JU Programme "Hydrogen for Sectorial Integration". 
A full list of the projects reviewed is given in Annex 1, Table 6. 

The programme generally addresses three main electrolyser types – Alkaline, Proton Exchange Membrane and 
Solid Oxide, as these are the three types of electrolyser at a sufficiently advanced stage that the FCH 2 JU has 
provided quantitative targets for the technologies. The FCH 2 JU has funded two further projects in the area of 
Proton Ceramic Electrolysers (PCEL), which is a technology that is still at a lower TRL level (compared to the 
other three technologies mentioned above) and therefore no KPI targets have been set for this technology. The 
two projects regarding this technology will be briefly discussed in this report. 

The  assessment  was  performed  during  2019  (summer  period).  Projects  were  divided  into  "completed"  and 
"ongoing" projects. Completed projects were considered to be those with a completion date before the end of 
2018, as the primary source for the Project KPIs was the final report (which is generally submitted within 3 
months of the end of the project). The full methodology outlined below was performed for completed projects, 
whilst a simplified methodology was performed for ongoing projects. 

Templates were created for each of the three main electrolyser technologies containing a series of KPIs, based 
on the list of programme targets given in the Addendum to the Multi-annual Work Program (MAWP) from 2018 
[4].  The KPI template was filled in for each completed project, using data obtained from the following sources, 
in order of priority: 

 

 

 

Project Final Report 

The latest update of the TRUST database 

Intermediate Project Reports   

  Other source documents. 

For ongoing projects, a simplified procedure was followed where the latest figures recorded for the specific KPIs 
were  obtained  from  the  TRUST  database.  These  were  supplemented  with  any  known  values  that  had  been 
achieved by the projects since the latest TRUST update. 

The KPI values obtained for the relevant projects were then compared against the SoA and target values and 
used to derive the summary tables presented in the relevant sections below. 

4 

 
 
 
 
 
 
 
3  FCH 2 JU Electrolyser Projects 

The FCH 2 JU has been funding projects towards the development of electrolyser technologies for hydrogen 
production since it was founded in 2008. In Figure 1, the cumulative level of EU funding from the FCH 2 JU 
towards  projects  related  to  the  different  electrolyser  technologies  is  shown,  for  those  Panel  5  projects 
specifically developing electrolyser technologies (for a full list of the relevant projects, see Annex 1). The value 
given in the plot includes the cumulative EU funding value against the project start year. It can be seen that the 
most funding has been applied to PEM electrolysers whilst lower levels of funding have been directed at alkaline 
and solid oxide electrolysers. A smaller amount of funding has also been provided for the two projects regarding 
Proton Ceramic Electrolysers (PCEL). 

Figure 1: Cumulative level of FCH JU funding versus project start year for electrolyser 
technologies 

Source: JRC based on data from FCH 2 JU, 2020. 

The online software TIM (Technology Innovation Monitoring) developed by the JRC has been used to provide an 
overview of organisations that have taken part in electrolyser development projects. TIM will be described in 
more detail in Chapter  5. Figure 2(a) shows those organisations involved in projects covered by Panel 5, i.e. 
those specifically looking at electrolyser development. In the plots, the size of the nodes (circles) is proportional 
to the number of projects a partner has been involved in whilst the thickness of the lines is proportional to the 
number of links (i.e. the number of  projects partners have been involved in together). TIM uses a  particular 
algorithm to cluster related items into a “Community”. Each community has a different colour.  

A number of key partners that are common to a number of projects can be identified (for example electrolyser 
manufacturers such as ITM or Hydrogenics, or research institutions such as CEA, DTU, Sintef and DLR). In the 
plot shown in Figure 2(b) the size of the circles represents the number of projects that contain at least one 
consortium  member  from  that  EU  member  state.  The  thickness  of  the  links  between  the  circles  shows  the 
number of projects in common. This plot shows that the countries that are active in the greatest number of 
projects tend to be the larger European economies of Germany, France, the U.K., Italy and Spain. Denmark is a 
notable exception. 

5 

€0€10€20€30€40€50€60201020112012201420152016201720182019Cumulative EU Funding / EURMillionsProject Start YearPEM ElectrolyserSO ElectrolyserAlkaline ElectrolyserPC Electrolyser 
 
 
 
 
 
 
 
 
Figure  2:  TIM  plots  showing  (a)  the  participants  for  Panel  5  projects  considered  in  this 
report.1; (b) EU member state participation for Panel 5 projects considered in this report.2  

Source: JRC (TIM) based on data from FCH 2 JU, 2020. 

1 The size of the node represents the number of projects a partner is involved in, whilst the thickness of the links 
represents  the  number  of  projects  in  common  between  the  linked  partners.  The  coloured  groupings  are 
potential clusters identified by TIM’s algorithm. The table shows the top 5 participants from the plot 

2 The size of the node represents the number of projects that has at least one participating organisation from that 
member state. The thickness of the links between the nodes is proportional to the number of projects those 
member states have in common. The table shows the top 5 countries represented. 

6 

(a)(b)ParticipantNumber ofprojectsCEA11ITM8SINTEF7Aragon Hydrogen Foundation6DTU;DLR5Member StateNumber ofprojectsGermany21France19Spain15Italy12UK;Denmark10HYDROGENICSFRAUNHOFERSUNFIRE 
 
 
 
 
 
 
                                           
4  Electrolyser Technologies 

4.1  Alkaline Electrolyser 

4.1.1  Operating Principles 

In  the  alkaline  electrolyser,  the  anode  and  cathode  operate  in  an  electrolyte  that  is  typically  25-30%  KOH 
solution.  A  separator  ensures  no  mixing  of  gases,  for  safety,  efficiency  and  gas  purity  reasons,  but  allows 
transport of water, and hydroxide ions, which provide ionic conductivity. At the cathode, water is converted to 
hydrogen gas and hydroxide ions, whilst at the anode hydroxide ions are converted to oxygen and water. The 
reactions can be summarised as follows: 

Cathode:  

4H2O(l) + 4e-  4OH-

(aq) + 2H2(g) 

Anode:    

Overall:   

4OH-

(aq)  O2(g) + 4e- + H2O(l) 

4H2O(l)  2O2(g) + 4H2(g) 

Typically, alkaline electrolysers are operated in the temperature range from 80-200C [5] and at pressures in 
the range from atmospheric to up to 50 bar  [6]. Water needs to be pre-treated before use and the product 
gases must be dried before release. Hydrogen with a purity of 99.7% can be produced [5]. 

4.1.2  State of the Art 

The alkaline electrolyser is a well-established technology for hydrogen production with relatively cost-effective 
stacks available in the megawatt range. Additional advantages of the alkaline electrolyser are that it does not 
use noble metal catalysts and that it is stable over a very long lifetime (often in excess of 100,000 hours) [7]. 
One drawback is that alkaline electrolysers experience high ohmic losses across the electrolyte and separator 
and hence operate at relatively low current densities compared to PEM electrolysers.   

A further issue is that historically the systems have shown poor dynamic behaviour, with limited load flexibility. 
This occurs because the separators are not very effective at preventing cross-diffusion of gases. Specifically, 
oxygen crossing to the cathode leads to a lowering in efficiency (as it can be converted back to water) and 
possibly, to safety issues, which are particularly evident in low load scenarios. These are challenges that need 
to be overcome for the use of alkaline electrolysers with Renewable Energy Sources (RES) such as wind or solar. 

Figure 3 shows the efficiency of commercial alkaline electrolyser systems (using publicly available data from 
online brochures and webpages) expressed as the energy consumption (in kWh) required to produce a kilogram 
of hydrogen, versus the size of the electrolyser system (in terms of system power). Electrolysers are included 
from the following companies: Pure Energy, McPhy, Hydrogenics, IHT, Thyssenkrupp. Data was also found for 
NEL electrolysers but only at stack rather than system level. For reference, the NEL electrolysers had a stack 
energy consumption of 42.3-49.0 kWh/kg. 

To compare directly to the FCH 2 JU target it is necessary that the same boundary conditions have been applied. 
For example, the FCH 2 JU target states that the hydrogen output pressure should be 30 bar. This is not always 
the case, however in  general the larger electrolysers on the market do  produce hydrogen at approx. 30 bar 
pressure. Smaller electrolysers tend to produce hydrogen at lower pressure. 

Performance gains for system efficiencies appear to be limited beyond a system size of approximately 100-300 
kW.  This  is  most  likely  due  to  the  modularity  of  systems  above  a  certain  size.  Based  on  the  data  currently 
publicly  available  from  the  manufacturers,  the  state-of-the-art  performance  by  alkaline  electrolysers  is 
~50 kWh/kg. These values correspond almost exactly to the FCH 2 JU target for 2020. 

7 

 
 
 
 
  
Figure 3:  Energy Consumption versus System Power for a range of commercially 
available alkaline electrolysers 

Source: JRC, based on publically available information from websites and online brochures. 

Information regarding CAPEX (Capital Expenditure) is much more difficult to ascertain. In general, companies 
do not provide this information publicly or alongside product specifications. However, one producer, NEL, states 
that the cost for alkaline electrolysers can currently vary from 1150 – 650 EUR/kW depending on system size 
[8, 9]. This is fairly consistent with the SoA value provided for 2017 by the FCH 2 JU of 750 EUR/kW assuming 
a 100 MW production capacity. A thorough literature study by Proost, Stolten et al [12] of future estimations of 
the costs of electrolyser technologies gives an expectation for the cost per kW of 700-1000 €2017/kWHHV-Output for 
alkaline  electrolysers.  The  fact  that  little  improvement  to  the  cost  of  alkaline  electrolysers  is  expected  is 
attributed to the maturity of this technology. 

4.1.3  Applications 

Historically, due to the challenges mentioned in the previous section, alkaline  electrolysers have mostly been 
deployed  in  a  continuous  mode,  e.g.  for  stationary  hydrogen  production  in  an  industrial  environment.  The 
FCH 2 JU  attempts  to  address  the  challenges  for  applications  where  the  electrolyser  needs  to  be  used 
dynamically (when coupled with renewable energy sources (RES) such as solar or wind or for the provision of 
grid services), through funding projects such as ELY4OFF, HPEM2GAS, QUALYGRIDS, H2FUTURE, DEMO4GRID 
and REFHYNE. 

8 

0.020.040.060.080.0100.0110100100010000100000Energy Consumption (kWh/kg H2)System Power (kW)FCH 2 JU Targets2020 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.1.4  Progress of the Programme against Targets for Key Performance Indicators (KPIs)  

The  focus  of  the  FCH  2  JU  has  been  to  develop  alkaline  electrolysers  for the  production  of  hydrogen  from 
renewable electricity, for energy storage and for grid balancing activities. These efforts aim at addressing the 
limitations  of  the  earlier  commercial  technologies  previously  mentioned.  Over  time,  a  clear  transition  from 
research to demonstration projects has been observed [11].  

The  FP7  projects  RESELYSER  and ELYGRID  focussed  on  developing  more  efficient, lower-cost,  high-pressure 
alkaline electrolysers. RESELYSER involved the development of novel separators and catalyst materials, whilst 
ELYGRID focussed on cell improvements (a new cell topology, leading to higher efficiency and higher current 
densities), power electronics and balance of plant. 

Following  directly  on  from  ELYGRID,  the  Horizon  2020  ELYNTEGRATION  project  targeted  the  design  and 
engineering  of  a  robust,  flexible,  efficient  and  cost-competitive,  multi-MW  system,  capable  of  dealing  with 
dynamic electric supplies from high renewable share sources. This was due to conclude with the demonstration 
of a high-pressure electrolyser for grid integration at the scale of 250 kW, although only a 108 kW system was 
ultimately installed. ELYNTEGRATION is currently being followed up by the DEMO4GRID project, which aims to 
realise  the  commercial  setup  and  demonstration  of  a  4  MW  electrolyser  system  in  Austria  with  a  targeted 
system efficiency of 52 kWh/kg H2, for grid balancing from renewable energy sources.  

QUALYGRIDS,  is  developing  standardised  testing  protocols  for  both  alkaline  and  PEM  electrolysers  for  the 
provision of grid services. The project DON QUICHOTE operated both alkaline and PEM electrolysers in a project 
designed to demonstrate hydrogen production from wind energy. 

From Panel 1 (Transport - Trials and Deployment of Fuel Cell Applications) projects aiming to demonstrate the 
deployment of electric vehicles and utilise electrolysers to provide hydrogen within Hydrogen Refueling Stations 
(HRS)  have  contributed  to  the  review.  CHIC  and  JIVE  are  two  projects  deploying  buses, whilst  MOBYPOST  is 
focussed on the deployment of a fleet of postal delivery vehicles. HYFIVE is a project deploying 110 fuel cell 
electric vehicles (FCEVs) across Europe. H2ME is deploying a range  of diverse FCEV vehicles and utilising 29 
hydrogen refuelling stations.  

Finally,  the  Panel  3  project  REMOTE  is  deploying  both  PEM  and  alkaline  electrolysers  in  a  number  of 
demonstration sites in isolated micro-grid or off-grid remote areas. 

The targets originating from the Addendum to the MAWP of the FCH 2 JU [4] for hydrogen production from 
renewable electricity for energy storage and grid balancing using alkaline electrolysers are summarised in Table 
2.  This table  also  includes SoA  values for  2012  and 2017.  The  values  provided  in  this table  originate  from 
agreement between the FCH 2 JU and a panel of industry experts. 

Table 2 also shows whether a target has been achieved to date. It should be noted that this assessment was 
performed in mid-2019 and the Programme is still ongoing. Therefore, where a target has not been reached 
and the SoA has not been improved upon to date, it is indicated by a “”Work in Progress” sign. Where it has been 
reached, it is indicated by a green tick. In certain cases, the SoA has been improved upon but not to the extent 
of achieving the target. Here, a grey tick is shown. This needs to be considered in the context regarding the scale 
of the project and the conditions under which the particular performance was achieved. In general, the vast 
majority  of  data  considered  for  alkaline  electrolysers  has  originated  from  projects  that  can  be  classed  as 
Demonstration  projects.  It  should  also  be  noted  that  projects  should  provide  data,  wherever  feasible,  under 
standard boundary conditions applying to all system KPIs (as defined in  Table 2). In general, it has not been 
possible to establish whether all data provided has been given under these standard conditions. 

Furthermore, it should also be mentioned that the KPIs considered do not really address the issue of integrating 
the technology with RES and the dynamic modes necessary for this purpose. 

9 

 
 
 
 
 
 
Electrical Consumption at Nominal Capacity (kWh/kg) 

This value is a representation of the overall efficiency of the system. It can be seen from Table 2 that between 
the 2017 SoA and 2030 there is an objective for a modest improvement in the efficiency of the systems in 
order to reduce the amount of electricity consumed per kg of hydrogen produced. These modest improvements 
most  likely  reflect  the  relatively  advanced  commercial  nature  of  the  technology.  The  fact  that  the  KPI  is 
measured at nominal capacity does not consider the influence on the efficiency of the system of operating at 
partial load or at over-capacity. 

It can be seen from Table 2 that projects have to date not improved upon the SoA value from 2017, although 
values for the KPI have been provided by a number of projects considered in this review. Whilst the data provided 
is confidential, the authors of this report have used the rated and actual efficiencies provided by the projects 
to calculate the values in the anonymised Figure 4, which shows all public data submitted for all years. 

These  values    are  generally  rated  values  of  deployed  commercial  electrolysers in  real-world  demonstration 
scenarios.  They  are  also  often  older  electrolysers  deployed  under  other  projects,  and  therefore  are  not 
necessarily representative of the current best commercial offerings. For comparison, the current state of the 
art for commercial alkaline electrolysers, as shown in Figure 3 is of the order of 50 kWh/kg for electrolysers of 
the size of 300 kW or more. It may be of use for the projects to declare two values in the case of advanced 
commercial electrolysers being deployed – the nominal system energy consumption of the commercial product 
(as a descriptive parameter) and the actual system energy consumption (as an operational parameter).  

In  general,  the  focus  of  the  Programme  has  been  on  enabling  the  utilisation  of  alkaline  electrolysers  with 
renewable energy technologies or demonstration of the technology at a larger scale. Therefore, it is unlikely 
that a major improvement in this particular parameter will be observed with the current suite of projects. A 
specific call dealing with game-changing materials or components to achieve the programme goals could be 
considered. 

Figure 4: Electrical Energy Consumption calculated from the Rated and Experimental 
System Electrical Efficiencies for Alkaline Electrolysers. SoA and Targets shown are the 
FCH JU values from 2017. Public submissions only. 

Source: JRC based on data from FCH 2 JU, 2020. 

10 

 
 
 
 
 
 
Capital Cost (€/(kg/d) or €/kW) 

Despite improvements in the capital cost of alkaline electrolysers in the period from 2012 to 2017, the FCH 2 JU 
has specified a further halving of the cost from 2017 to 2030 to less than 500 EUR/kW (note, this somewhat 
contradicts the expectations provided in [10] discussed in section 4.2.2). The FCH 2 JU states that it will call for 
demonstration projects that  enable cost reduction through further scale-up. Furthermore, it aims for “better 
integration with renewable electricity sources”. This presumably will require improvement/modification in the 
technology whilst simultaneously reducing CAPEX, but would potentially lead to lower hydrogen costs.  

According to the latest version of the MAWP, projects should provide a capital cost estimation based on 100 MW 
production  volume  for  a  single  company,  for  a  10-year  system  lifetime  running  in  steady  state  operation, 
whereby end of life is defined as a 10% increase in energy required for hydrogen production. This cost should 
not include stack replacements, but should include transformers and rectifiers. 

Only two projects provided any sort of cost estimate. In general, projects working with alkaline electrolysers are 
often using commercial or near-commercial technologies. It is likely that not all relevant data is being submitted 
due to commercial sensitivity reasons. Whilst one of the submitted values did improve on the SoA, the 2020 
target has not been achieved to date.  

Operational and Maintenance (O&M) Cost (€/(kg/d)/yr) 

This is foreseen to remain at 2% of the Capital Cost. Therefore, a halving in Capital Costs leads to a similar 
target of halving the O&M Costs in the period from 2017-2030. This KPI refers to the estimated cost averaged 
over the first 10 years of the system, including any potential stack replacements but not including the cost of 
electricity. 

As for Capital Cost, only two projects have submitted (confidential) values regarding O&M Costs. These values 
did not improve on the SoA. The cost KPIs as a whole for alkaline technologies are of limited benefit. It is likely 
that they are being addressed but in general, low TRL projects are more willing to provide estimates which (by 
their nature) will be more inaccurate, whilst high TRL projects are unwilling to provide the information due to 
commercial sensitivity.  

Degradation (%/1000hrs) 

This  is  defined  as  the  percentage  efficiency  loss  when  run  at  nominal  capacity.  Slight  improvements  in 
degradation rates are targeted for the period 2017-2030. The modest improvements specified are again likely 
due to the advanced state of the art in this area (with units capable of operating in excess of 100000 hours), 
or simply a need to retain this performance when making improvements elsewhere. The target values stated 
for this KPI are presumably aimed at static operation. Therefore, the target does not address the issue of poor 
load  flexibility  or  use  under  dynamic  operation  (for  example  when  coupled  with  RES),  which  are  the  key 
challenges that need to be addressed with this technology.    

In general, projects are not declaring this value. Whilst a lifetime of the electrolyser is sometimes provided, the 
degradation rate is not supplied. This may be because the degradation rate of these electrolysers is not known 
to be problematic when the alkaline electrolyser is operated under steady state conditions. While there are no 
programme  KPIs  specifically  associated  with  load  flexibility  or  response  times  of  the  technology,  the 
degradation rate under flexible operating conditions would be a relevant parameter. Only one project provided 
such a (confidential) figure and as expected degradation rates were higher when under flexible load. 

11 

 
 
 
 
 
 
 
 
 
Current Density (A/cm2)  

Some  significant  improvements in  the  current  densities have  been  targeted  for  alkaline  electrolysers in  the 
period 2017-2030. Low current densities are a drawback of AEL when compared to PEMEL and occur due to 
the high ohmic losses experienced across the liquid electrolyte and separator.  

A number of projects (five) provided values for the current densities used. None of the projects have exceeded 
the 2017 SoA value to date. It would appear that to achieve the current density targets outlined in the MAWP, 
specific research activities targeting this KPI and dealing with game-changing materials or components may be 
required, as have recently been undertaken for PEM electrolysers.  

Use of critical raw materials as catalysts (mg/W)  

For alkaline electrolysers this corresponds specifically to cobalt used at the anode of the electrolyser. In general, 
it  has  not  been  possible  to  find  a  great  deal  of  information  on  the  use  (or  lack  thereof)  of  cobalt  in  the 
electrolyser  projects  concerned.  Very  few  projects  provide  specific  information  regarding  the  nature  of  the 
catalyst used. This is generally either because of the commercial sensitivity of this information, because the 
company producing the electrolyser is not part of the consortium (in certain demonstration projects) or both. 

It should be noted that whilst the amount of cobalt used is a quantifiable target stated by the MAWP, a field 
for its submission is not included in TRUST. 

Summary 

In general, the above performance against the MAWP KPI targets would suggest that the Programme was not 
performing successfully in the area of alkaline electrolysers. However, this is really only a part of the story as 
the MAWP KPIs do not really capture the essence of what the FCH 2 JU funded projects have been attempting 
to achieve regarding alkaline electrolysers. 

Two major goals of the Programme which are not reflected in the MAWP KPIs are: 

(i) 

(ii) 

to  improve  how  alkaline  electrolysers  are  connected  to  renewable  sources;  improving  their 
flexibility under variable and partial load and increasing their slow response times.  

the scale-up of alkaline electrolyser systems 

The projects DEMO4GRID and ELYNTEGRATION have been demonstrating AEL technology in dynamic operation, 
for example for use in the provision of grid services. The KPIs mentioned above do not encompass the major 
challenge of integrating electrolysers with Renewable Energy Sources. Furthermore, upscaling for this specific 
application is a challenge. DEMO4GRID, for example is installing a 3.2 MW pressurised alkaline electrolyser for 
this application. QUALYGRIDS, has been developing standardised testing protocols for both alkaline electrolysers 
for the provision of grid services, whilst DON QUICHOTE operated alkaline electrolysers in a project designed to 
demonstrate hydrogen production from wind energy. In general, the higher TRL demonstration projects needed 
to use well-established alkaline technology that would not be likely to challenge beyond the state of the art. 

In terms of scale, the electrolyser deployed in demonstration projects  have  been steadily increasing in  size, 
culminating  in  the  new  project  DJEWELS  which  started  in  2020  and  will  demonstrate  a  20  MW  alkaline 
electrolyser for the production of green methanol in industrial and commercial conditions.   

12 

 
 
 
 
 
 
 
 
 
 
Table  2:  MAWP  objectives  and  achievements  for  hydrogen  production  from  renewable  electricity  for  energy  storage  and  grid  balancing 
using alkaline electrolysers [4] 

No. 

Parameter and Unit 

SoA 2012  SoA 2017  Target 

Achieved?  Target 

Achieved?  Target 

Achieved? 

2020 

2024 

2030 

Generic System 

1 

2 

Electricity Consumption @ Nominal Capacity 
(kWh/kg) 

57 

51 

50 

Capital Costs (€/(kg/d) 

                      (€/kW) 

8,000 

1,600 

(~3,000) 

(750) 

1,250 

(600) 

3 

O&M Cost (€/(kg/d)/yr) 

160 

32 

26 

Stack 

4 

5 

6 

Degradation (%/1000hrs) 

Current Density (A/cm2) 

Use  of  Critical  Raw  Materials  as  Catalyst 
(mg/W) 

- 

0.3 

8.9 

0.13 

0.12 

0.5 

7.3 

0.7 

3.4 

49 

1,000 

(480) 

20 

0.11 

0.7 

2.1 

48 

800 

(400) 

16 

0.10 

0.8 

0.7 

Source: JRC, based on data provided by the FCH 2 JU, 2020 and SoA and targets provided in the Addendum to the Multi-annual Work Plan of the FCH 2 JU [4]. 

Notes: *Standard boundary conditions that apply to all system KPIs: input of 6kV AC power and tap water; output of hydrogen meeting ISO 14687-2 at a pressure of 30 
bar. Correction factors may be applied if actual boundary conditions are different.  

2) Capital cost are based on 100MW production volume for a single company and on a 10-year system lifetime running in steady state operation, whereby end of life is 
defined as 10% increase in energy required for production of hydrogen. Stack replacements are not included in capital cost. Cost are for installation on a pre-prepared site 
(fundament/building and necessary connections are available). Transformers and rectifiers are to be included in the capital cost.  

13 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3) Operation and maintenance cost averaged over the first 10 years of the system. Potential stack replacements are included in O&M cost. Electricity cost is not included 
in O&M cost.  

4) Stack degradation defined as percentage efficiency loss when run at nominal capacity. For example, 0.125%/1000h results in 10% increase in energy consumption over 
a 10 year lifespan with 8000 operating hours per year  

6) The critical raw material considered here is cobalt. Other materials can be used as the anode or cathode catalysts for alkaline electrolysers. 7.3 mg/W derives from a cell 
potential of 1,7 V and a current density of 0,5 A/cm2, equivalent to 6.2 mg/cm2. 

14 

 
 
 
 
4.2  PEM Electrolyser 

4.2.1  Operating Principles 

The proton exchange membrane electrolyser (also known as polymer electrolyte membrane electrolyser) or PEM 
electrolyser (PEMEL) is the reverse analogue of the proton exchange membrane fuel cell. 

At the anode of the electrolyser, water is converted to oxygen gas and protons with the release of electrons. 
The solvated protons then pass through the proton conducting membrane to the cathode where they recombine 
with electrons to form hydrogen. The half- and full-cell reactions are therefore: 

Anode:    

2H2O(g)  O2 +4H+ + 4e- 

Cathode:  

4H+ + 4e-  2H2(g)  

Overall:   

2H2O(g)  O2(g) + 2H2(g) 

4.2.2  State of the Art 

The  catalysts  used  in  a  PEMEL  are  typically  platinum  for  the  cathode  (hydrogen  production)  and  an 
iridium/ruthenium  oxide  at  the  anode  (oxygen  production),  both  supported  on  carbon.  The  typical  proton 
conducting  membrane  used  is  Nafion  (with  sulfonic  acid-based  functional  groups).  The  nature  of  these 
membranes,  which  need  to  be  hydrated  to  maintain  conductivity,  limits  the  operating  temperature  of  the 
electrolysers to a temperature of range of typically 25-80C. The water must be carefully pre-treated to avoid 
certain impurities; in particular cations such as Ca+ and copper ions can cross-over and clog the membrane [5]. 
PEMEL have a typical hydrogen discharge pressure of 10-50 bar, although there are conceptual designs for up 
to 350 bar [12]. 

The main advantages of PEMEL include the high current density that can be produced, high voltage efficiencies 
and the fact that these electrolysers operate well under dynamic operation and partial load, and are  highly 
responsive.  This  makes  PEMEL  the  best  suited  technology  for  coupling  with  RES.  The  main  drawbacks  are 
durability3 (related to catalyst loss and membrane lifetime) and cost, partly due to the catalysts consisting of 
expensive platinum group metals.  

In order to assess the commercial state of the art, data has been collected for a range of commercially available 
PEM electrolyser systems in the same way that was done for the alkaline electrolysers (using publicly available 
data from online brochures and webpages), and displayed in Figure 5. The efficiency of the system expressed 
as the energy consumption (in kWh) required to produce a kilogram of hydrogen is shown versus the size of the 
electrolyser system (in terms of system power).  Electrolysers are included from Proton (Nel), ITM, Hydrogenics 
and Areva. 

As mentioned previously, in order to compare directly to the FCH 2 JU targets it is necessary that the same 
boundary conditions have been applied. This is not always the case, however in general the larger electrolysers 
on the market do produce hydrogen at approx. 30 bar pressure which is one of the main stipulations. Smaller 
electrolysers tend to operate at lower pressure. 

As for alkaline electrolysers, performance gains appear to be limited beyond a system size of approximately 
100-300 kW. This is again most likely due to the modularity of systems above a certain size. The current state-

3 The term “durability” is used generically within this document to mean the ability to withstand damage or decay. 

In terms of KPIs, it can be seen to relate specifically to the degradation rate and/or system lifetime. 

15 

 
 
 
 
 
 
                                           
of-the-art for PEM electrolysers is ~55 kWh/kg at larger system sizes, which corresponds almost exactly to the 
FCH 2 JU target for 2020.  

Figure 5: Energy Consumption versus System Power for a range of commercially 
available PEM electrolysers 

Source: JRC, based on publically available information from websites and online brochures 

As for alkaline electrolysers, it is difficult to obtain information regarding the CAPEX of PEM electrolysers. Proost, 
Stolten et al [10] have provided a thorough review of future estimations of the costs of PEM electrolysers and 
give an expected range of  400-1000 €2017/kWHHV-Output. The wider range of possible future cost estimates for 
PEM electrolysers when compared to alkaline, represents the earlier stage of the technology and therefore the 
greater potential for future cost reductions, in particular through the reduction in use of platinum group metals. 

4.2.3  Applications 

PEM electrolysers have high current densities compared to other electrolyser technologies. Furthermore, they 
are  highly  responsive  and  have  no  issues  with  operating  at  partial  load  making  them  an  ideal  solution  for 
coupling with intermittent Renewable Energy Sources such as wind or solar photovoltaics.  

16 

0.020.040.060.080.0100.0120.0140.00.1110100100010000100000Energy Consumption (kWh/kg H2)System Power (kW)FCH 2 JU Targets2020 
 
 
 
 
 
 
 
 
 
 
 
4.2.4  Progress of the Programme against Targets for Key Performance Indicators (KPIs) 

Early  Panel  5  FCH  JU  projects  under  FP7  regarding  PEM  electrolyser  development,  mainly  focussed  on 
improvements at the level of the stack. PRIMOLYZER targeted the efficiency, current density, durability and cost 
of  the  electrolyser  stack  through  the  development  of  novel  catalyst  and  membrane  materials  and  through 
operation at higher pressures (100 bar). NEXPEL also looked at catalysts and membranes in order to replace 
the most expensive materials, whilst targeting a stack efficiency in excess of 75%. NEXPEL was built on via a 
follow-up project, NOVEL where a 1 kW laboratory-scale system was developed using the materials developed 
under NEXPEL and targeting 70% system efficiency (LHV). Again, the major focus was on the reduction in cost 
of  key  components  (catalysts,  bipolar  plates)  and  an  increase  in  durability.  A  further  early  project, 
ELECTROHYPEM, had a similar focus, performing research into novel catalyst/support combinations, alternative 
membranes and ultimately incorporating them into a prototype stack capable of operation over a wide pressure 
and temperature range.   In  recent projects, the focus seems to  have developed from  low TRL research and 
innovation  to  applications  of  PEM  electrolyser  technologies  at  a  larger  scale.  The  first  of  these  projects, 
MEGASTACK, which was funded under FP7, focussed on the design of a large capacity electrolyser (3-4 MW), in 
order to provide sufficient capacity for HRS, Power-to-Gas and grid-balancing applications.  

The  project  DON  QUICHOTE  installed  and  tested  both  an  alkaline  and  a  PEM  electrolyser  to  demonstrate 
hydrogen  production  from  wind  energy.  Furthermore,  the  ongoing  project  QUALYGRIDS  will  establish 
standardised testing protocols for electrolysers performing electrical grid services.  

Later calls include many projects demonstrating applications of PEM electrolyser technologies at a larger scale. 
HPEM2GAS has been developing a low cost PEM electrolyser for grid management on the scale of 180-300 kW, 
including  balance  of  plant  and  an  improved  stack  design.  The  project  targeted  a  3-fold  increase  in  current 
density whilst maintaining competitive efficiency and seeking to minimise costs.  HYBALANCE has been set up 
to demonstrate the feasibility of central large-scale electrolysers to provide grid services, coupled with hydrogen 
supply for mobility and industry. The total capacity of the PEM is electrolyser is 1 MW from two stacks. Similarly, 
BIG HIT should utilise a 1 MW PEM electrolyser as part of a hydrogen territory, using energy from wind and tidal 
turbines to produce hydrogen to power a local harbour and supply an HRS for fuel cell vehicles. The HAEOLUS 
project will install a 2 MW electrolyser at a remote wind farm which will be operated under energy storage mini-
grid and fuel production configurations and designed for flexibility and for remote operation. H2FUTURE will 
perform a demonstration of a 6MW electrolysis power plant. The atmospheric pressure electrolyser will be pre-
qualified to provide grid-balancing services, whilst the replicability of the experimental results at larger scale 
for the steel industry will be studied. The REFHYNE project will install a 10 MW PEM pressurised electrolyser (20 
bar) to supply hydrogen to the hydrogen pipeline system at a refinery. The electrolyser will need to be highly 
responsive to the demands of the plant. It will be the largest PEM electrolyser in the world and will be designed 
as a building block for 100 MW electrolysers. The ELY4OFF project will develop and demonstrate an autonomous 
off-grid electrolysis system linked to renewable energy sources. 

Whilst these recent projects will go a long way to demonstrating PEM electrolysers in a range of real-world 
scenarios at higher TRL levels, a recent FCH 2 JU call has asked for more fundamental research and innovation 
on "game-changer" electrolysers. This would suggest that the large facilities being developed are still having 
issues achieving the KPIs of cost, efficiency and lifetime. With this in mind, the project PRETZEL will develop a 
25 kW electrolyser, based on a patented technology which will allow it to operate at a pressure difference of 
100 bar, and which should lead to current densities of 4-6 A cm-2 (considerably in excess of the KPI target for 
the FCH JU in 2030) and an overall system efficiency of 70%. Costs are also targeted by the use of non-precious 
metal cell coatings and novel catalyst supports. A second new project, NEPTUNE, will also seek to reduce costs 
at the cell, stack and system level and will also target the current density KPI with a value of 4 A cm -2, while 
maintaining the nominal energy consumption. 

Two further completed projects  working with PEM electrolysers have  measured and stated KPIs  which have 
been used in this report. The project HYFIVE was a Panel 1 project deploying 110 fuel cell vehicles across Europe. 

17 

 
 
 
 
 
As  part  of  that  roll  out,  six  new  hydrogen  refuelling  stations  were  added  to  the  European  network  and 
performance data from the electrolysers used in those refuelling stations will be included here. PHAEDRUS was 
a Panel 2 project aiming at developing and validating a new concept for hydrogen retail refuelling stations. A 
demonstration prototype PEMEL producing 5 kg of hydrogen a day was built whilst a design for a 200 kg a day 
system was prepared.  

There are also a number of ongoing projects from Panels other than Panel 5, which have provided some relevant 
data to the following section. In particular a number of projects from Panel 1, which involve the deployment of 
electrolysers  in  HRS  for  demonstration  purposes  have  been  included.  H2ME  and  its  successor  H2ME2  both 
provide data on the deployment of electrolysers in projects aiming to expand hydrogen refuelling infrastructure 
to supply hydrogen to large fleets of commercial and passenger fuel cell electric vehicles. ZEFER has a similar 
goal for captive fleets such as taxis and private hire vehicles. Finally, the Panel 3 project REMOTE is deploying 
both PEM and alkaline electrolysers in a number of demonstration projects in isolated micro-grid or off-grid 
remote areas. 

The targets originating from the Addendum to the MAWP of the FCH 2 JU [4] for hydrogen production from 
renewable electricity for energy storage and grid balancing using PEM electrolysers are summarised in Table 3 
(at the end of this chapter)Table 2. This table also includes SoA values for 2012 and 2017. The values provided 
in this table originate from agreement between the FCH 2 JU and a panel of industry experts. 

Table 3 also shows whether a target has been achieved to date. This needs to be considered in the context 
regarding the scale of the project and the conditions under which the particular performance was achieved. In 
contrast to the previous section on AEL, the obtained data comes from a mix of Research and Demonstration 
projects. It should also be noted that projects should provide data, wherever feasible, under standard boundary 
conditions applying to all system KPIs (as defined in Table 3). In general, it has not been possible to establish 
whether all data provided has been given under these standard conditions. 

In general, there are more projects considering PEM electrolysers than the other electrolyser types and, perhaps 
due to the earlier stage of the technology commercialisation, more information is being shared with the FCH 2 
JU. 

Electrical Consumption at Nominal Capacity (kWh/kg) 

This value is a representation of the overall efficiency of the system. It can be seen that between the 2017 SoA 
and  2030  a  more  significant  improvement  in  terms  of  this  KPI  are  expected  in  comparison  to  alkaline 
electrolysers. This is consistent with the fact that PEMEL are at an earlier stage of development and therefore 
greater scope for improvement is still envisaged.  

In general, this parameter is one of the most reported figures for projects, which are performing research at 
the system level. A lower value will be found at stack level when the energy consumption of the balance of 
plant is not included.  

In some cases, values for this parameter are given directly, whereas in other cases they can be calculated from 
the rated and experimental system efficiencies. Figure 6 shows these calculated values for all public submitted 
data. From this plot, it can be seen that in principle some of the electrolysers have rated efficiencies superior 
to even the target for 2030. Experimentally, there are also projects demonstrating performance well ahead of 
the target curve, which is encouraging.   

It should be noted that the typical commercial state of the art value for PEM electrolysers is 55 kWh/kg (based 
on the literature review conducted as part of this report), for systems in excess of 100 kW. A number of projects 
have stated targets that will improve significantly on the SoA. The electrolysers in HyBalance and ELY4OFF are 
expected to reach an energy consumption of 54 and 50 kWh/kg, respectively. HPEM2GAS aims to achieve 48 
kWh/kg at system level [13].  

18 

 
 
 
 
 
Figure 6: Electrical Energy Consumption calculated from the Rated and Experimental 
System Electrical Efficiencies for PEM Electrolysers. SoA and Targets shown are the FCH 
JU values from 2017. Public data only. 

Source: JRC based on data from FCH 2 JU, 2020. 

Capital System Costs projections (€/(kg/d) or €/kW) 

A KPI that is of considerable importance if PEM electrolysers are to become a commercial success is the system 
cost. The FCH 2 JU has stated that the state of the art for this KPI has reduced considerably in the period from 
2012 to 2017, but still requires a further reduction from 2900 €/(kg/d) to 1000 €/(kg/d) (or alternatively, 1200 
€/kW  to  500  €/kW)  by  2030  (as  shown  in  Table  3).  Compared  to  alkaline  electrolysers,  there  is  greater 
opportunity for cost reduction as the technology is at a much earlier stage of development. A recent study by 
Proost,  Stolten  et  al  [10]  has  reviewed  a  wide  range  of  industry  and  academic  predictions  for  electrolyser 
technologies and has concluded that the CAPEX of PEM electrolysers will ultimately settle between 1000 €/kW 
and 400 €/kW. This broad range represents a wide degree of uncertainty and may depend on the level to which 
PGM loadings can be reduced or replaced at the electrodes of the PEM electrolyser.  

According to the MAWP Addendum, the capital cost estimates should be based on a "100 MW production volume 
for a single company and on a 10-year system lifetime running in steady state operation, whereby end of life 
is defined as 10% increase in energy required for production of hydrogen. Stack replacements are not included 
in capital cost. Cost are for installation on a pre-prepared site (fundament/building and necessary connections 
are available). Transformers and rectifiers are to be included in the capital cost." [4]  

Six projects have made predictions regarding the ultimate cost of their technology, although as some of the 
projects presented predate the MAWP addendum, the assumptions on which values were calculated are not 
always the same, or necessarily clear. The majority of these predictions are confidential, although  ELY4OFF 
recently predicted a CAPEX of 800 €/(kg/d) for a 100 MW annual production scale [13].  

However, the timescales involved in achieving large-scale production and the remaining uncertainty in take up 
of the technology mean that there are still a great deal of unknowns and these values should be taken with 
caution.   

19 

 
 
 
 
 
 
 
Operational and Maintenance (O&M) Cost (€/(kg/d)/yr) 

As for AEL, over the timeline involved this is foreseen to remain at approx. 2% of the Capital Cost per year over 
the  period  2017-2030.  According  to  the  MAWP  Addendum  the  O&M  costs  have  the  following  definition: 
Operation and maintenance cost averaged over the first 10 years of the system. Potential stack replacements 
are included in O&M cost. Electricity cost is not included in O&M cost. 

Five  projects  have  made  an  estimate  of  this  value,  however  these  values  were  generally  confidential.  The 
majority of demonstration projects, which would be best-placed to improve on this cost parameter, have not 
provided  information,  most  likely  because  of  commercial  sensitivity  of  this  data.  The  projects  which  are 
reporting the O&M Cost do not seem to be approaching the FCH 2 JU SoA value. As the predicted CAPEX costs 
are considerably more positive, this suggests that a 2% O&M fixed cost ratio of CAPEX for PEM electrolysers 
may not be realistic.   

Hot Idle Ramp Time (s) 

This parameter is seen as being particularly important for PEM electrolysers as this technology is expected to 
be  the  most  suited  for  grid  balancing  services.  Therefore,  there  is  an  ambitious  target  to  reduce  the 
responsiveness of the system at hot idle conditions from 10s to 1s by 2030. 

The hot idle ramp time for a PEM electrolyser is defined in the MAWP addendum as "The time from hot idle to 
nominal power production, whereby  hot idle means readiness of the system for immediate ramp-up. Power 
consumption  at  hot  idle  as  percentage  of  nominal  power,  measured  at  15°C  outside  temperature."  Multiple 
projects have provided a value for the hot idle time (although this value is usually confidential), several of which 
improve on the SoA and one project which has achieved the 2030 target. 

Cold Start Ramp Time (s) 

As for the hot idle ramp time, this is seen as an important parameter of PEM electrolysers for integration with 
fluctuating RES. An ambitious target of a 10s ramp up from -20°C to nominal power has been stated for 2030. 

The cold start ramp time is defined in the MAWP Addendum as "The time from cold start from -20°C to nominal 
power".  The  same  projects that  provided  hot  idle  ramp  times  provided  values  for  the  cold  start  ramp  time, 
although it seems that the future targets will be more difficult to achieve with only one project submitting a 
(confidential) value that improves on the SoA. 

Footprint (m2/MW) 

The overall footprint of a PEM electrolyser system is likely to be reduced by increasing  current densities and 
producing cells with larger cross-sectional areas. It could also be related to improvements in Balance of Plant 
(BoP) design. A reduction from 120 m2/MW in 2017 to 45 m2/MW is targeted by 2030.   

Values for the footprint of the electrolysers have been provided by a number of demonstration projects. The 
values obtained are clearly superior to the state of the art, with the value reported by a number of projects 
even improving upon the target value for 2030, including a value of 10 m2/MW achieved by H2FUTURE [13] 
which is an order of magnitude better than the target for 2020.  

Whilst this would suggest that this KPI is no longer appropriate for the deployment of large-scale electrolysers, 
it should be noted that the values achieved by the two off-grid projects (ELY4OFF and REMOTE) are still higher 
than the SoA, hence for off-grid units this may remain a reasonable target. 

20 

 
 
 
 
 
 
 
 
 
Degradation Rate (%/1000 hours) 

The  stack  degradation  rate  is  defined  as  the  percentage  efficiency  loss  when  running  the  stack  at  nominal 
capacity e.g. a degradation rate of 0.125%/1000h corresponds to a 10% increase in energy consumption over 
a 10 year lifespan for a system operating 8000 hours per year. A somewhat more challenging target has been 
set for PEM electrolysers than for alkaline, due to the improvement necessary in enhancing the lifetime of the 
MEAs of PEM electrolysers. Issues are usually due to degradation of the membranes or loss of active catalyst 
material. 

In reality, whilst this is a crucial parameter regarding the uptake of the technology, a lack of long-term testing 
of  stacks  often  leads  to  extrapolation  from  short-term  testing.  This  is  not  always  reliable  as  multiple 
degradation processes with different timescales may exist. Furthermore, some projects only report the change 
in  voltage  needed  to  maintain  a  particular  output  (µV/h).  Again,  multiple  gradients  may  be  observed  with 
different timescales, making extrapolation difficult. Furthermore, the range of conditions used (including the 
length of test from which the final value is extrapolated) has made it difficult to compare between projects. 

That  being  said,  several  projects  have  declared  degradation  rates  that  are  ahead  of  the  curve  in  terms  of 
achieving the targets laid down in the MAWP. Several of these projects appear to have achieved the 2030 target 
of 0.12%/1000 hrs, although all submitted values were confidential. 

However, at this point significant care needs to be taken when interpreting the data for degradation rate, in 
particular in combination with the conditions being used when the degradation rate is measured, such as the 
current density (A cm-2) and the PGM catalyst loadings (mg/W).  

A further consideration is whether the degradation has been measured under steady state or flexible operating 
conditions. Projects which are looking at flexible operation in combination with RES to perform grid-balancing 
services  have  submitted  higher  degradation  rate  values,  which  suggest  that  there  is  still  a  considerable 
challenge for the durability of PEM electrolysers when operating in these modes.  

Current Density (A/cm2) 

Although PEM electrolysers supply higher current densities than alkaline electrolysers, an improvement from 
2.0 A/cm2 to 2.5 A/cm2 is targeted from 2017 to 2030. The major challenge comes from the need to combine 
increasing current densities with a reduction in the quantity of precious metal catalysts used. 

No project has given a public value that exceeds the SoA however, projects have submitted values to the TRUST 
database which even exceed the target for 2030. However, it should be noted that achieving higher current 
densities as an isolated KPI is not on its own significant. Combining this with low PGM values, high durability 
and demonstration at a higher TRL level will be necessary. Interestingly, the FCH 2 JU has recently funded two 
low TRL projects looking for fundamental research and "game-changer" electrolyser technologies. Two projects 
were  funded  (PRETZEL  and  NEPTUNE)  which  are  targeting  current  densities  of  4 A/cm2  or  higher,  while 
maintaining the nominal energy consumption.  

Use of critical raw materials as catalysts (mg/W)  

PEM electrolysers usually use platinum, iridium and  sometimes ruthenium in their state of the art catalysts. 
This is a major hurdle to reduction in the capital cost of the electrolyser. However, these PGM catalysts are 
necessary in order to achieve the high current densities that PEM electrolysers provide. Often the type of catalyst 
used, and the catalyst loading is considered commercially sensitive information and is therefore sometimes not 
provided for demonstration projects which involve commercial (or near commercial) electrolysers. 

For low TRL projects, a range of different catalysts and catalyst loadings may be attempted under different 
conditions. Lower loadings may lead to lower performance, so it is difficult to assess a reported value for this 
KPI without combining with other relevant KPIs. Often projects provide a loading in mg/cm2.  In order to convert 

21 

 
 
 
 
 
 
this  to  mg/W,  a  nominal  current  density  and  voltage  is  required  at  optimal  performance.  This  is  often  only 
established for a mature system. Furthermore, it should be noted that the value provided in TRUST is the catalyst 
loading. In the case where oxide materials are used it is not clear whether the mass corresponds to (for example) 
iridium or iridium oxide. For the present assessment, the numbers provided in TRUST have been used directly.  

A number of different projects have provided details of the catalyst loadings in the form of mg/W, or provided 
sufficient data to calculate this value under a nominal condition. However, as mentioned for degradation, it is 
important to consider the context under which these experiments are being performed. Certain projects may 
have  only  provided  data  at  single  cell  level,  or  may  not  have  yet  provided  corresponding  values  for  the 
degradation rate or the system efficiency. However, projects are attempting to utilise systems with relatively 
low PGM loadings and if these projects can achieve the range of performance (efficiency, degradation, cost etc.) 
whilst maintaining these levels, then the impact of the programme will be as intended. As can be seen in Table 
3, projects have managed to achieve the 2020 target and in certain cases even lower values, but the data has 
to be considered in the context mentioned above. 

Use of critical raw materials as catalysts Pt (mg/W) 

Similar trends are observed when Pt is considered in isolation. The values obtained achieve the 2020 target and 
beyond.  However,  this  again  needs  to  be  considered  in  combination  with  other  achieved  KPIs  (such  as 
degradation rate) to be put in context. i.e. simply achieving a high mg/W value is not useful if this catalyst has 
a high degradation rate. Therefore, it is important to consider catalyst loading, current density, efficiency and 
degradation as related KPIs and not in isolation. 

It would be beneficial if these links between KPIs become formalised e.g. in the case that you report a particular 
degradation rate, that the other parameters contributing to that value must be reported simultaneously. It could 
be advantageous to report the degradation rate based on a given operational regime whilst reporting current 
density. This is to avoid the reporting of an encouraging degradation rate at a lower current density and separate 
reporting of a higher current density leading in turn to reduced lifetime. 

Summary 

In the case of PEMEL projects, it can be seen that a considerable number of the individual MAWP KPI targets 
have been achieved. However, it should be noted that they have not all been achieved by the same individual 
project, and that it is important to think of these targets collectively in order to advance the state of the art of 
a  commercial  PEM  electrolyser.  For  example,  it  may  be  possible  to  reduce  PGM  loading  whilst  maintaining 
current density, but this may lead to reduced durability. Therefore, the achievement of individual targets, whilst 
extremely encouraging, does not necessarily mean that these targets are no longer appropriate for 2030, simply 
that they must all be achieved simultaneously by a commercial electrolyser on this timeframe.  

In this respect, whilst the main conclusion from the alkaline section was that the performance against the MAWP 
KPIs gives a falsely negative impression of the success of the programme (as the programme of work did not 
really address the issues highlighted by the KPIs), the opposite is true to a certain extent for PEMFC. i.e. that the 
abundance  of  green  ticks  in  Table  3  should  not  give  the  impression  that  the  work  is  now  done  or  that  the 
technology is considerably ahead of schedule, and in the future programme following the FCH 2 JU, it should 
be more clearly expressed that these targets are interlinked.   

22 

 
 
 
 
 
 
Table  3:  MAWP  objectives  and  achievements  for  hydrogen  production  from  renewable  electricity  for  energy  storage  and  grid  balancing 
using PEM electrolysers [4] 

No. 

Parameter and Unit 

SoA 2012 

SoA 2017 

Target 
2020 

Achieved? 

Target 
2024 

Achieved? 

Target 
2030 

Achieved? 

Generic System 

1 

2 

Electricity  Consumption  @  Nominal 
Capacity (kWh/kg) 

60 

58 

55 

Capital Costs (€/(kg/d) 

                      (€/kW) 

8,000 

2,900 

(~3,000) 

(1,200) 

2,000 

(900) 

3 

O&M Cost (€/(kg/d)/yr) 

160 

58 

41 

Specific System 

4 

5 

6 

Hot idle ramp time (s) 

Cold start ramp time (s) 

Footprint (m2/MW) 

60 

300 

- 

10 

120 

120 

2 

30 

100 

Notes:  Availability is fixed at 98%.  

1) to 3) similar conditions as for alkaline technology (Table 2)  

52 

1,500 

(700) 

30 

1 

10 

80 

50 

1,000 

(500) 

21 

1 

10 

45 

4)  The  time  from  hot  idle  to  nominal  power  production,  whereby  hot  idle  means  readiness  of  the  system  for  immediate  ramp-up.  Power  consumption  at  hot  idle  as 
percentage of nominal power, measured at 15°C outside temperature.  

5) The time from cold start from -20°C to nominal power  

23 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
No. 

Parameter and Unit 

SoA 2012  SoA 2017 

Target 
2020 

Achieved? 

Target 
2024 

Achieved? 

Target 
2030 

Achieved? 

Stack 

7 

8 

9 

Degradation (%/1000hrs) 

0.375 

0.250 

0.190 

0.125 

0.12 

Current Density (A/cm2) 

Use of Critical Raw Materials as Catalyst 
(mg/W) 

10 

Use of Critical Raw Materials as Catalyst 
– Pt (mg/W) 

1.7 

- 

- 

2.0 

5.0 

1.0 

2.2 

2.7 

0.7 

2.4 

1.25 

0.4 

2.5 

0.4 

0.1 

7) similar conditions as for alkaline technology (Table 2)  

9) This is mainly including ruthenium and iridium as the anode catalyst and platinum as the cathode catalyst (2,0 mg/cm 2 at the anode and 0,5 mg/cm2 at the cathode). 
The reduction of critical raw materials content is reported feasible reducing the catalysts at a nano-scale. 

Sources: JRC, based on data provided by the FCH 2 JU, 2020 and the Addendum to the Multi-annual Work Plan of the FCH 2 JU [4].. 

24 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
4.3  Solid Oxide Electrolyser 

4.3.1  Operating Principles  

Solid oxide electrolysers (SOEL) are high temperature electrolysers (usually >800C) which are equivalent to 
Solid Oxide Fuel Cells (SOFC) operating in reverse mode [14]. In the solid oxide electrolyser cell (SOEC) steam is 
fed into the porous cathode.  

Under an applied voltage, the steam is reduced to hydrogen and oxide ions at the cathode/electrolyte interface. 
Oxide ions then pass through the dense conducting solid electrolyte to the anode where they are oxidised to 
oxygen gas. The reactions occurring can be summarised as: 

Cathode:  

2H2O(g) + 4e-  2O2- + 2H2(g) 

Anode:    

Overall:   

2O2-  O2(g) + 4e- 

2H2O  O2(g) + 2H2(g) 

It should be noted that SOECs have the potential to be used to produce syngas as, at these high temperatures, 
a  SOEL  fed  with  steam  and  CO2  can  produce  both  H2  and  CO  in  the  cathode  reaction.  In  general,  the  high 
temperature operation allows for increased fuel flexibility and they are less susceptible to fuel impurities than 
low temperature electrolysers. Hydrogen is typically produced at a discharge pressure of 10-40 bar [12]. 

4.3.2  State of the Art 

SOEL materials have to be tolerant of the high temperatures required for operation.  The cathode ("hydrogen 
electrode") must have a porous structure, high catalytic activity, high electrical and ionic conductivities, and be 
compatible with the electrolyte (including similar thermal expansion). Typically, a composite of Ni and yttria-
stabilised zirconia (YSZ) is used. The nickel acts both as an electrocatalyst and provides electrical conductivity 
whilst YSZ provides ionic conductivity. Zirconia is chosen for its mechanical strength and corrosion resistance 
resulting  in  the  ability  to  withstand  high  temperatures,  however  it  can  undergo  phase  transformation 
(monoclinic to tetragonal at 1373K) hence alkaline earth or rare earth metal oxides such as yttria (Y2O3) [15] or 
scandia (Sc2O3) are added to provide stability. The cathode is often used as the support for a thin electrolyte 
layer,  hence  mechanical  strength  is  important.  The  main  alternatives  to  Ni-YSZ  are  lanthanum  strontium 
manganese oxides (LSM) which have a perovskite structure, along with doped versions of this material. The 
electrolyte must have high ionic conductivity, a dense structure to prevent gas diffusion, be electrically insulating 
and  have  high  mechanical  strength.  YSZ  is  also  typically  used  as  the  electrolyte  in  SOEL  [e.g.  [15,  16]. 
Alternatives are scandia-stabilised zirconia (ScSZ) (e.g. [17, 18]), doped lanthanum gallates (LaGaO3) (e.g. [19]) 
or ceria-based materials (e.g. [20, 21]). The anode (typically LSM) must show similar properties to the cathode, 
along  with  high  catalytic  activity  for  oxygen  evolution.  There  are  issues  with  anode  delamination  from  the 
electrolyte during high temperature operation, which have been attributed to differences in ionic conductivity 
at the interface leading to a build-up in oxygen pressure. Other materials issue include a mismatch in thermal 
expansion coefficients between layers and diffusion of materials across the electrolyte/electrode interfaces due 
to chemical instabilities. Sealing of the cells is also a major challenge at these high temperatures. Unlike PEMEL 
and  AEL, which  have planar geometries, SOEL can  be  have either planar or tubular geometries. The  tubular 
design  has  been  developed  as  it  makes it  easier to  seal  the  air from the  fuel.  However,  in  general, tubular 
designs currently tend to have higher resistance (and lower performance) than planar designs.  

25 

 
 
 
 
 
   
 
Solid  Oxide  Electrolysers  are  generally  at  the  Research  and  Innovation  stage  as  there  are  still  significant 
materials challenges to be overcome, although there are a number of demonstration projects underway. Only 
a handful of companies advertise solid oxide electrolyser products for sale e.g. Sunfire (Germany) [22]; mPower 
(Germany) [23]; OxEon Energy (US) [24]. With the possible exception of Sunfire, it would appear these are at a 
relatively early commercial stage in comparison to PEM and alkaline electrolysers. Whereas the other companies 
sell SOFC units, and only advertise bespoke SOEL systems to order, Sunfire have specialised in the electrolysers 
and  provide  fixed-sized  units  ("hydrogen  generators")  as  products,  in  an  analogous  way  to  the  companies 
producing alkaline and PEM electrolysers. The Sunfire Hylink unit [25] is a modular unit with a rated AC power 
of 150 kW. It has an efficiency of 82% (LHV) at the nominal rated power and produces 40 Nm3/hr of hydrogen 
at a system energy consumption of 41.2 kWh/kg. 

4.3.3  Applications 

SOEC have the advantage that they operate at extremely high efficiency, due to the high temperature operation. 
They would therefore be particularly useful in industrial applications where waste heat can be recycled to the 
electrolyser stacks. 

Furthermore, as previously mentioned, solid oxide electrolysers have the potential to be used for the production 
of syngas from steam and CO2. This is a possible route to reduction of CO2 emissions via creation of a useful 
industry precursor. Therefore, SOEC could be utilised in both hydrogen and syngas production. 

The  potential  for  use  in  a  reversible  manner  would  also  suggest  an  application  in  energy  storage  and  grid 
balancing in connection with Renewable Energy Sources (RES), however, the major drawback of SOEC is that 
the high temperature operation leads to long start-up times and slow response. Furthermore, whilst they are 
reversible in principle, systems are often optimised for either SOFC or SOEL mode.   

4.3.4  Progress of the Programme against Targets for Key Performance Indicators (KPIs) 

For Solid Oxide Electrolysers, where the technology is at an earlier stage of development, the projects funded 
by the FCH 2 JU have generally been at a lower TRL level than some of those funded for alkaline and PEM 
electrolysers. Only three projects in the area of Solid Oxide Electrolysers were completed by the end of 2018 
(ADEL, SOPHIA and HELMETH). 

The project ADEL aimed to optimise the electrolyser lifetime by operating at lower temperatures. It also targeted 
high  energy  efficiency  at  the  level  of  the  complete  system  including  the  heat  and  power  source  and  the 
electrolyser unit. The project SOPHIA was set up to design and construct a 3 kWe pressurised system coupled 
to a solar energy source. The concept of co-electrolysis (of steam and CO2) was also addressed along with LCA 
and a techno-economic assessment to investigate different power-to-gas scenarios. HELMETH aimed to directly 
integrate high temperature electrolysis with methanation to demonstrate a power-to-gas route with synthetic 
methane as the energy storage medium.  

Of the ongoing projects, SELYSOS and ECO focus on degradation issues which limit the SOEL and aim to reduce 
the operating temperature,  specifically via  developing and testing novel electrode and electrolyte  materials. 
SELYSOS is mainly focussed on water electrolysis whilst ECO is mainly directed at co-electrolysis.  

More recent projects are also attempting to develop the scale of the technology for demonstration purposes. 
GRINHY has been working on developing a 120 kWel stack with a lifetime of 10000 hours and a production loss 
of <1%/1000 hrs which would achieve the FCH 2 JU target for 2024. It also aims to achieve efficiency in excess 
of 80% (LHV) and to provide hydrogen at the purity required for the steel industry for more than 7000 hours 
of operation. A follow-up project, GRINHY 2.0, has recently been approved which will integrate a 720 kW SOEL 

26 

 
 
 
 
 
 
 
into  an  iron  and  steel  works,  whilst  achieving  an  improved  efficiency  of  up  to  84%  (LHV).  The  project  has 
targeted 13000 hours of operation, at an availability of 95% (achieving the FCH 2 JU 2020 target).  

The final project regarding SOEL, which recently began, is REFLEX. This project is developing a smart energy 
hub based on reversible solid oxide technology, including a field demonstration that will link with solar and mini-
hydro renewable energy sources.  

The targets originating from the Addendum to the MAWP of the FCH 2 JU [4] for hydrogen production from 
renewable electricity for energy storage and grid balancing using SOEL electrolysers are summarised in Table 
4 (at the end of this chapter). This table also includes SoA values for 2012 and 2017. The values provided in 
this table originate from agreement between the FCH 2 JU and a panel of industry experts. 

Table 4 also shows whether a target has been achieved to date. This needs to be considered in the  context 
regarding the scale of the project and the conditions under which the particular performance was achieved. 

In contrast to AEL and PEMEL, all the projects that have supplied data to the graphs can be considered Research 
projects. As this technology is at a much earlier stage of development, this is reflected in the ambitious targets 
that  have been set.  It  should also be mentioned that a  higher  proportion of the  data  was  considered to  be 
“Public” as opposed to “Confidential” due to the lower TRL nature of the projects. 

It should be noted that the values obtained should be provided under standard boundary conditions applying to 
all system KPIs. In general, it has not always been possible to establish whether all data provided has been 
given under these standard conditions. 

In addition to the listed KPIs, the high temperature operation means that start up times are particularly long 
and therefore the technology is not overly responsive. This is not addressed specifically by any of the FCH 2 JU 
targets, but would need to be addressed for applications involving integration with RES. 

Due to the limited number of projects considering Solid Oxide electrolysers, there is insufficient data to consider 
trends  for  this  technology.  On  its  own,  the  project  GRINHY  is  providing  a  considerable  amount  of  the  data 
considered at System level, with a few values supplemented from other projects. 

For SO electrolysers it is perhaps better to consider the MAWP KPIs as broad indicators of what performance 
will  be  necessary  to  achieve  some  form  of  technical  breakthrough,  rather  than  for  technical  monitoring  of 
projects  over the  lifetime  of  the  FCH  JU, as the  targets  do  not  necessarily  match  with  the  TRL level  of  the 
projects being undertaken. This will depend on what the approach of the FCH JU towards SOEL will be in the 
future (i.e. will projects be aimed more at scaling up of the technology or towards more fundamental research). 

Electrical Consumption at Rated Capacity (kWh/kg H2) 

Solid Oxide electrolysers are already a very highly efficient technology compared to other types of electrolyser 
due to their high temperature operation, which means that part of the energy required for water splitting is 
supplied through heat energy. Only a modest improvement in the electrical consumption at rated capacity is 
expected, from 41 kWh/kg in 2017, to 37 kWh/kg in 2030. 

As  for  the  other  forms  of  electrolyser,  a  plot  has  been  prepared  using  all  values  submitted  to  the  TRUST 
database for the Rated and Experimental System Efficiency to calculate the Electrical Energy Consumption of 
the Systems. This is shown in Figure 7. This figure only contains public data for the two projects which have 
produced any data at system level, HELMETH and GRINHY. In this respect, it does not provide as much additional 
information other than to confirm that the projects are performing close to the SoA levels. 

27 

 
 
 
 
 
 
 
Figure 7: System Electrical Energy Consumption calculated from the Rated and 
Experimental System Efficiencies provided in TRUST (all projects, all years of TRUST) for 
SO Electrolysers. Public data only. 

Source: JRC based on data from FCH 2 JU, 2020. 

Capital Cost (€/(kg/d) or (€/kW)  

As Solid Oxide electrolysers are in the early stage of development, a considerable cost reduction will be required 
in order for them to become commercially viable. The target for 2030 is almost an order of magnitude reduction 
in cost compared to the current state of the art. 

Only  two  projects  have  provided  an  estimation  of  the  Capital  Cost.  HELMETH  submitted  an  estimate  of 
2200 €/(kg/d) in TRUST which agrees favourably with both the state of the art and the stated target values of 
the FCH 2 JU. This value corresponds to 1210 €/kW, assuming 5.5 kg/day for a 10 kW system. At PRD 2018, 
the GrInHy project also made a cost projection of 1500 EUR/(kg/d) for production at the 100 MW scale [13]. This 
is a very encouraging figure but it should be remembered that this is a prediction and it is not known within 
what timeframe such costs will be achievable. 

O&M Costs (€/(kg/d)/yr) 

As  for  the  other  electrolyser  technologies,  the  target  value  for  the  O&M  cost  has  been  given  as  a  fixed 
percentage compared to the  Capital Cost.  However, for SOEL it is fixed at 5% rather  than the  2% used for 
alkaline/PEM electrolysers. Presumably this is because the technology is at an earlier stage of development, so 
maintenance costs are deemed to be higher. 

No solid oxide electrolyser project has provided an estimate of the O&M cost KPI as described in the MAWP. 
This is not surprising as the technology is at a particularly early stage and therefore this KPI is not currently 
that appropriate, beyond giving a general guidance. It should be noted that the other electrolyser technologies 
have struggled to achieve the O&M Cost targets as laid out by the FCH 2 JU. 

28 

 
 
 
 
 
 
 
 
 
Production Loss (%/1000hrs)  

Material issues at high operating temperatures lead to degradation. For SOEL the degradation rate is defined 
differently to low temperature electrolysers. Production loss is defined as the degradation at thermo-neutral 
conditions in percent loss of production-rate (hydrogen power output) at constant efficiency. A target of 1.9% / 
1000 hours is given for 2020 in the MAWP [4] as can be seen in Table 4. 

A number of projects have reported figures for the voltage degradation rate under varying conditions. Whilst 
the ADEL project did not provide a publicly available value for this KPI during its duration,  a press release by 
SOLIDPower as a follow-up to the project [26], stated that the SOEL had been operated for over 6000 hours at 
700C and a current density of 0.5 A/cm2 with no significant degradation. 

The GrInHy project aims at a 1%/1000h degradation rate (and in a recent update has  stated that they have 
achieved 0.8%/1000 hours at constant temperature in electrolysis mode at 0.5 A/cm² compared to thermo-
neutral  voltage  [13]).  In  general,  however,  long  term  testing  at  system  level  and  under  realistic  operating 
conditions, is still required to confirm the lifetime targets. Degradation rates should be observed in combination 
with  the  operating  current  density,  as  milder  operating  current  densities  are  generally  selected  as  nominal 
operating current density or as current density in long-term tests. It was, however, also recently reported that 
the ECo project had demonstrated an electrolyser stack with an electrical efficiency degradation rate of only 
0.05%/1000 hrs [13]. The detailed conditions under which this was achieved were not provided. 

In general, it would be preferable to be able to present the degradation rate versus the current density. However, 
from the TRUST database, as the parameters are entered separately, it cannot be assumed that the degradation 
rate and the current densities presented were obtained simultaneously.  

Reversible Efficiency (%) 

In principle, a SOEL can also be used reversibly utilising the process observed in an SOFC, hence the KPIs include 
the reversible efficiency, although not all systems are designed or optimised for use in reversible mode. Only 
the projects GRINHY, GRINHY 2.0 and REFLEX are working on reversible systems.  The only project to submit a 
value for the reversible efficiency is GRINHY. This value of 48%, provided through TRUST is close to the SoA 
value of 50%. 

Reversible Capacity (%) 

This is the percentage of the electric capacity in fuel cell mode in relation to the electrolyser mode. Multiple 
projects have provided a value for this KPI, and one has provided a confidential value that achieves the 2020 
target of 25%. 

Availability (%) 

No state of the art figure for availability of the technology is given in Table 4, however this will be a key indicator 
of the reliability of the new technology going forward. In general, low TRL R&D projects are not expected to be 
able to supply a figure for this KPI. Whilst some availability values have been submitted to TRUST, they have 
usually  been  over  short  experimental  periods.  The  values  have  ranged  from  50-100%  availability, but  until 
longer term testing has been performed, the authors do not feel the data provided is sufficiently relevant. 

Summary 

In general, SOEL technology is at a lower TRL level than AEL or PEMEL. Furthermore, a smaller number projects 
have been undertaken regarding this technology and certain important projects are still ongoing and will provide 

29 

 
 
 
 
 
 
 
 
relevant data within the timeframe of the FCH 2 JU programme. With this in mind it can be seen than some 
progress is being made towards the targets stated in the MAWP which are concomitant with the stage of these 
projects. As for the other electrolyser technologies it is important to consider the KPIs as a complete package, 
hence achievement of individual MAWP KPI targets (for example production loss) should be tempered with the 
knowledge that this needs should be achieved at the efficiency target level stated in the MAWP.  

It should be noted, that a new project, MULTIPLHY, which aims to install and operate the world’s first megawatt-
scale (2.4 MW) SOEL at a biofuels refinery in the Netherlands, in order to provide more than 60 kg/h hydrogen 
will mark a significant scale-up milestone in the technology which is not captured by the MAWP targets.  

30 

 
 
 
 
 
Table  4:  MAWP  objectives  and  achievements  for  hydrogen  production  from  renewable  electricity  for  energy  storage  and  grid  balancing 
using high-temperature SOEL [4] 

No. 

Parameter and Unit 

SoA 2012 

SoA 2017 

Target 
2020 

Achieved? 

Target 
2024 

Achieved? 

Target 
2030 

Achieved? 

Generic System* 

Electricity  Consumption  @ 
capacity (kWh/kg) 

rated 

na 

1 

2 

3 

4 

Availability (%) 

Capital cost (€/(kg/d)) 

O&M Cost (€/(kg/d)/yr) 

Specific System 

Reversible efficiency (%) 

Reversible capacity (%) 

5 

6 

Stack 

41 

na 

40 

95% 

12,000 

4,500 

600 

225 

50% 

54% 

20% 

25% 

39 

98% 

2,400 

120 

57% 

30% 

37 

99% 

1,500 

75 

60% 

10 

na 

na 

na 

na 

na 

7 

Production Loss (%/1000hrs) 

na 

2.8 

1.9 

1.2 

0.5 

Source: Addendum to the Multi-annual Work Plan of the FCH 2 JU [4]. Source: JRC, based on data provided by the FCH 2 JU, 2020. 

Notes:  
*Standard boundary conditions that apply to all system KPIs: input of AC power and tap water; output of hydrogen meeting ISO 14687-2 at atmospheric pressure. Correction factors may be applied if actual boundary 

conditions are different.  

31 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
For 3) and 4) please refer to Table 3 (similar conditions as for alkaline technology)  
5) Reversible efficiency is defined as the electricity generated in reversible mode of the electrolyser, divided by the lower heating value of hydrogen consumed.  
6) Reversible capacity is defined as a percentage of the electric capacity in fuel cell mode in relation to the electrolyser mode  
7) Degradation at thermo-neutral conditions in percent loss of production-rate (hydrogen power output) at constant efficiency. Note this is a different definition as for low temperature electrolysis, reflecting the 

difference in technology. 

32 

 
 
 
 
4.4  Protonic Ceramic Electrolyser 

4.4.1  Operating Principles 

Protonic Ceramic Electrolysers (PCEL) are high temperature electrolysers with a solid oxide electrolyte. In the 
case of the PCEL, the conducting ion is the proton. 

When electricity is applied, water is oxidised at the anode to form oxygen gas and release protons, which then 
pass through the proton-conducting solid oxide electrolyte. These protons then combine at the cathode to form 
hydrogen gas. These reactions are identical to those in PEMEL.  

Cathode:  

4H+ + 4e-  2H2(g) 

Anode:    

Overall:   

2H2O(g)  O2(g) + 4H+ + 4e- 

2H2O  O2(g) + 2H2(g) 

As for SOEL, cells can be planar or tubular. 

4.4.2  State of the Art 

PCEL is being considered because of a number of potential advantages over other forms of SO electrolyser. 
Firstly, PCELs produce dry hydrogen (as the water stream is separate) at the high pressure of the electrolyser. 
The production of pure oxygen at the maximum pressure of the electrolyser (which can have safety risks) is 
also avoided. Furthermore, proton conductivity requires lower activation  energies than oxide ion conductivity, 
meaning that the technology could ultimately operate at intermediate temperatures of 400-600C, significantly 
lower than for SOEL. 

The materials used in PCEL must be stable at high steam pressures and compatible to ensure no delamination 
of electrodes/electrolyte under operation at high temperature. The cathodes in PCELs are nickel-based and need 
to be efficient and stable at high hydrogen pressure (the GAMER project, for example, aims to produce hydrogen 
at  30 bar).  The  Ni  is  manufactured  in  a  cermet  as  a  mechanical  electrode  support.  The  proton  ceramic 
electrolytes are generally based on acceptor-doped BaZrO3 perovskite oxides that hydrate to become proton 
conducting in the presence of steam. They can be combined with  barium cerate, which is less stable but has 
lower grain boundary resistance. A range of air electrodes have been demonstrated in the literature including 
LSM  [27],  LSCF  (La0.6Sr0.4Co0.2Fe0.8O3-)  [27],  PBSCF  (PrBa0.5Sr0.5Co0.1Fe0.5O5+)  [27]  and  more  complicated 
combinations such as BSCF-BCZY62 (Ba0.5Sr0.5Co0.8Fe0.2O3- - Ba0.98Ce0.6Zr0.2Y0.2O3)  [28]. This is the area of PCEL 
which is least developed and where there is most room for improvement.  

PCEL  are  at  a  much  earlier  stage  of  development  than  other  electrolyser  technologies,  hence  most  of  the 
development  occurring  is  at  low  TRL  level,  and  on  the  laboratory  scale.  Although  the  conductivity  of  the 
electrolytes for PCEL is high, the achievable current densities are typically an order of magnitude lower than 
those achievable with oxygen ion conducting SO electrolysers. The key drawbacks with the technology seem to 
be poor activity for the water oxidation reaction and high ohmic resistance [27]. There are only a few exceptions 
where current densities higher than 100-200 mA cm-2 have been achieved. Choi et al achieved a current density 
of  1.8  A  cm-2  at  600C  and  an  operating  voltage  of  1.3  V  with  an  estimated  efficiency  of  76%.  Kim  et  al. 

33 

 
 
 
 
 
 
 
 
 
achieved 0.75 A cm-2 at 1.3 V and 600°C however they believed that the electrolyte in their experiments was 
conducting both protons and oxygen ions, leading to higher rates [28]. 

4.4.3  Applications 

PCEL could potentially be relevant to refineries and the chemical industry where waste heat could be used to 
improve the efficiency of the electrolysis process. Furthermore, in an analogous manner to oxide ion conducting 
SOEL, PCELs also have the potential for co-electrolysis of steam and CO2 into syngas. Therefore, tolerance to 
CO2 is also important. 

4.4.4  Key Performance Indicators (KPIs) and Targets 

The Multi-Annual Work Program does not have specific targets for PCEL technology as it is at a lower TRL than 
the other electrolyser technologies under consideration. However, the major challenges facing the technology 
are currently: 

 

 

Insufficient durability  

Insufficient efficiency 

  High capital cost 

The progress against the state of the art will therefore be discussed in terms of the targets set by the individual 
projects to overcome the challenges mentioned above. 

4.4.5  Progress against State of the Art - PCEL 

Two projects have been funded in the course of the FCH 2 JU regarding proton ceramic electrolysers (PCEL).  

ELECTRA was a FP7 project, which developed tubular PCEL cells and a kW-size multi-tubular module operating 
at 700°C for production of hydrogen from steam at up to 20 bar pressure. Tubular designs can handle pressure, 
sealing and lifetime issues better than planar cells. ELECTRA incorporated Y and Ce substituted BaZrO 3 (BZCY) 
electrolytes, Ni-BZCY cathodes and perovskite oxide anodes [29]. New materials and architectures for steam 
electrodes with promising electrochemical performance and stability under oxidising steam-rich conditions were 
developed and incorporated into a multi-tube electrolysis module. Delays in component production meant that 
this was not tested within the framework of the project, but a 1 kW electrolysis prototype was demonstrated 
beyond the ELECTRA timeframe. 

In  the  follow-up  project,  GAMER,  high  volume  production  of  the  novel  tubular PCECs  will  be  established  for 
operation at temperatures of 500-700C [30]. A 10 kW electrolyser system will be designed, built and operated 
for 2000 hours, delivering pure dry hydrogen at 30 bar pressure, progressing the technology from TRL 3 to 
TRL 5.  

34 

 
 
 
 
 
 
 
 
 
 
 
5  Literature and Patenting Trends in Electrolyser Technologies 

5.1  Literature and Patent Searching Methodologies 

In this section, a general overview will be given regarding the trends in literature and patenting for electrolyser 
technologies.  To  determine  the  level  of  literature  and  patent  activity  regarding  electrolyser  technologies  by 
geographical  region,  statistics  have  been  obtained  and  analysed  using  two  different  methodologies,  which 
provide different information and have different advantages.  

The first methodology is outlined in detail in [31] and uses the most up-to-date available information from the 
PATSTAT database (updated at JRC in August 2018). PATSTAT is the European Patent Office’s (EPO) Worldwide 
Patent Statistical Database, which has been specifically developed for use by government/intergovernmental 
organisations and academic institutions.  

Due  to  the  time  lag  involved  in  the  patenting  process,  data  is  shown  up  to  2014,  which  was  the  last  fully 
completed year available at the time of the analysis. There are three main reasons for the significant lag in the 
patent  data  observed  in  PATSTAT:  (i)  Patent  documents  are  published  18  months after their application;  (ii) 
Cleaning and processing of the data coming from authorities other than the EPO takes significant time; (iii) The 
EPO database is only released twice a year. Therefore, in general, 100% coverage can only be assumed at least 
4 years in advance of the analysis (this data was analysed in early 2019, so the last complete year was 2014).  

Statistics  have  been  obtained  for  relevant  classifications  according  to  the  Cooperative  Patent  Classification 
(CPC) [32]. Within the classification "Y tags" are used, an additional class used in parallel to the traditional CPC 
classes, which was created specifically for low-carbon, sustainable and climate change mitigation technologies. 
The statistics provided in this document are combined for the tags Y02E 60/366 and Y02E 70/10, which are 
derived from the CPC hierarchy as shown in Table 5.  

Y02E 60/366 is a more general tag regarding hydrogen technology inventions relating to the electrolysis of 
water, whilst Y02E 70/10 is for inventions where hydrogen is formed by electrolysis where the energy used is 
non-fossil fuel in origin.  

Statistics  are  given  for  patent  families,  which  involve  all  the  filed  patent  applications  relevant  to  a  distinct 
invention, preventing multiple counting of that invention. A fraction of the family is allocated to each applicant 
and linked to the country where the applicant organisation is registered. For this reason, it is possible to have 
non-integer numbers within this study. For a detailed description of how these fractional counts are calculated 
please refer to [31].  

35 

 
 
 
 
 
 
 
 
 
Table 5: Explanation of the patent classification hierarchy for Y02 60/366 & Y02E 70/10 

Tag 

Y 

Y02 

Y02E 

Description 

General tagging of new technological developments; 

General  tagging  of  cross-sectional  technologies  spanning  over  several  sections  of  the 
International Patent Classification (IPC) 

Technologies or applications for mitigation or adaptation against climate change 

Reduction of greenhouse gas (GHG) emissions, related to energy generation, transmission 
or distribution 

Y02E 60/00 

Enabling  technologies  or  technologies  with  a  potential  or  indirect  contribution  to  GHG 
emissions mitigation 

Y02E 60/30 

.Hydrogen technology 

Y02E 60/36 

. .Hydrogen production from non-carbon containing sources 

Y02E 60/366 

. . .by electrolysis of water 

Y02E 70/00 

Other energy conversion or management systems reducing GHG emissions 

Y02E 70/10 

Hydrogen from electrolysis with energy of non-fossil origin, e.g. PV, wind power, nuclear 

Source: JRC based on information from the CPC, 2020. 

The second tool/methodology that has been used for gaining information regarding not only patents but also 
literature, is TIM (Tools for Innovation Monitoring) developed by the JRC. TIM’s database contains three types of 
documents: scientific publications (articles, conference proceedings, reviews, and book chapters), patents and 
granted EU projects. The scientific publications contained in the database are those published after 1996 in the 
Scopus database (Elsevier). The EU projects are all those from Framework Programme 5 (beginning in 1998) 
onwards and are extracted from the CORDIS database. The patent documents are extracted from the PATSTAT 
database from the European Patent Office (all patents with a priority date from 1996 onwards). Contrary to 
the methodology used above, all patent applications are included (up to 2019) however, the same lag in terms 
of completeness of data will be observed as for the methodology mentioned above, as the source is the same. 

TIM has been used to provide complementary results. It provides useful network visualisations to display data. 
These contain nodes and edges (circles joined together by lines). The size of the node corresponds to the number 
of  data  items  (documents)  in  the  dataset,  whilst  the  size  of  the  edge  corresponds  to  the  number  of  items 
(documents) in common between the two nodes. Nodes are assigned to communities. The colour of the node 
represents the community to which it belongs. TIM uses a particular algorithm (Louvain Modularity algorithm) 
to  cluster  nodes  together  in  communities.    The  JRC  has  prepared  a  tailor-made  version  of  TIM,  capturing 
technologies relevant to FCH 2 JU activities using specific keyword searches. Data deriving from FCH JU projects 
cover calls 2008-2017. The TIM plots contained within this section have been prepared using this tailor-made 
version of TIM. 

36 

 
 
 
 
 
 
 
5.2  Patent data trends based on the CPC Classification 

Figure 8 shows the number of patent families filed versus the country/region code. High value patent families 
are patent applications filed in more than one patent office and are shown in green. It can be seen that Japan 
is the most active at filing patents related to electrolysers whereas the European Union has the highest number 
of high value patents. Figure 9 shows the level of patenting per EU country, where the most active countries 
are Germany, France and the United Kingdom. Figure 10 shows how the number of patent families has evolved 
per region in the period 2000-2014. 

Figure 8: Number of patent families filed versus country/region code for the tags Y02E 
60/366 and Y02E 70/10 from 2000-2014 

Source: JRC, based on EPO Patstat data, 2020. 

Figure 9: Number of patent families filed to the EU-28 countries for the tag Y02E 60/366 
and Y02E 70/10 from 2000-2014 

Source: JRC based on EPO Patstat data, 2020. 

37 

0100200300400500600700CNEUJPKRROWUSNumber of Patent FamiliesCountry / Region CodeLow valueHigh Value020406080100120ATBEBGCYCZDEDKESFIFRHUIEITLUMTNLPLPTROSESKUKNumber of Patent FamiliesEU Member State Code 
 
 
 
 
 
 
 
 
It  is  clear that  whilst  Japan  has  been  patenting  consistently  in  this  technical  area  for  many  years,  in  other 
regions (in particular the EU and China) a steady increase in the number of inventions related to electrolysers 
has occurred in recent years. 

Figure 10: Number of patent families filed per year for the tag Y02E 60/366 from 2000-
2014 

Source: JRC based on EPO Patstat data, 2020. 

Another interesting statistic relates to the flow of inventions. This shows in which other non-domestic patent 
offices, patents are being filed.  

Figure 11 shows the flow of inventions (from left to right) for electrolysers (e.g. 98.0 patent families originating 
in the EU are being filed in other jurisdictions in the ratio shown by the flow). This figure shows, for example, 
that the EU, Japan and the US file patents broadly across all geographical regions, whereas China selectively 
patents in Japan. 

Finally, Figure 12 displays the leading companies filing patents in this area. It can be seen that large Japanese 
corporations dominate the top 10, with the only European entries being CEA and Siemens. It should be noted, 
that Proton Energy Systems Inc. (US) were the highest ranked company that exclusively deals in electrolyser 
technologies (in 12th place with 11.5 patent families). They have since been purchased by NEL to create the 
world’s largest electrolyser company [33]. 

38 

050100150200250300200020012002200320042005200620072008200920102011201220132014Number of Patent FamiliesYearROWUSKRJPCNEU 
 
 
 
 
 
 
 
 
Figure 11: Sankey diagram showing the flow of inventions by geographical region (for 
2000-2014). 

Source: JRC based on EPO Patstat data, 2020 

Figure 12: Leading organisations with filed patent families in the electrolyser field (for 
2000-2014). 

Source: JRC based on EPO Patstat data, 2020. 

39 

020406080100Honda Motor Company (JP)Toshiba (JP)CEA (Commissariat a L'Energie Atomique) (FR)Hitachi Shipbuilding Eng Co. (JP)Mitsubishi Heavy Ind Ltd, (JP)Siemens Ag (DE)Samsung Electro Mechanics Ltd. (KR)University of Tsinghua (CN)Kobelco Eco Solutions Co. Ltd. (JP)Mitsubishi Electric Corporation (JP)Number of Patent Families 
 
 
 
 
 
 
5.3  Literature and Patenting Visualisations using TIM 

In  order  to  relate  geographic  factors  to  specific  electrolyser  technologies,  the  tailor-made  version  of  TIM 
produced specifically for the FCH 2 JU has been used. In particular, the TIM datasets for the three types of most 
common electrolyser (alkaline, PEM and SO). Note that the datasets include all information include in the TIM 
database  which  runs  from  1996  to  the  current  date.  In  these  figures,  the  size  of  the  nodes  represents  the 
number of documents, whilst the thickness of the lines joining the nodes represents the number of documents 
in  common  between  different  geographical  locations  (e.g.  a  peer-reviewed  paper  co-authored  by  groups  in 
different  countries). The  different coloured groupings are assigned by TIM based on the  Louvain  Modularity 
algorithm, which assigns the different nodes to a particular community based on statistics.   

The  first  series  of  plots,  shown  in  Figure  13  correspond  to  the  “Electrolysis”  keyword  in  the  “Alkaline 
Electrolysers” space of the tailor-made version of TIM.  

It is clear from Figure 13 (a) that in terms of total publications (journal articles, conference proceedings, reviews, 
book chapters, EU projects and patents), the EU is world-leading (when taken as a single entity) followed by 
China, Japan and the US. A similar pattern is reflected in the level of activity in terms of journal articles as 
confirmed in Figure 13 (b) however it is interesting to observe that this is not at all the case regarding patents. 
Very few patent applicants in this field originate from Europe, which is dominated by Japan, China  and South 
Korea.  

Figure 13: TIM plots showing the EU/World countries producing the most publications 
regarding alkaline electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

In Figure 14 equivalent data is displayed for countries within the EU. Here it can be seen that alkaline electrolyser 
research  is  predominantly  focussed  in  Germany  with  other  significant  contributions  from  Italy,  the  United 
Kingdom, Spain and France. Similar patterns are observed between journal articles and patents, although as 
mentioned before very few patents in this field are originating in Europe. 

40 

(a) All documents (1452)(b) Articles (720)(c) Patents (521) 
 
 
 
 
 
 
 
 
 
Figure 14: TIM Plots showing the EU countries producing the most publications regarding 
alkaline electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

Figure 15 and Figure 16 show equivalent images produced regarding PEM electrolyser technology. It can be 
seen that the EU has a considerably more dominant position regarding this technology when it comes to the 
total number of publications and the number of journal articles published. Again, the picture for patenting is 
more mixed, with significant contributions from Japan, China and South Korea. 

Within Europe, Germany again has a very dominant position in this technology, regarding the total number of 
publications,  with  significant  other  contributions  from  France  and  the  United  Kingdom  (Figure  16).  The 
dominance of Germany is even more noticeable when considering patents. 

Figure 15: TIM Plots showing the EU countries producing the most publications regarding 
alkaline electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

41 

(a) All documents (329)(b) Articles (226)(c) Patents (8)(a) All documents (1268)(b) Articles (700)(c) Patents (232) 
 
 
 
 
  
 
 
 
 
Figure 16: TIM Plots showing the EU countries producing the most publications regarding 
PEM electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

Finally, Solid Oxide electrolysers are considered in Figure 17 and Figure 18. Again, Europe appears to be highly 
active in this area with the other major players being China and the US. A similar pattern is observed for both 
journal articles and patents. Interestingly, Japan appears to be considerably less active in terms of publications 
in this technology area. Within the EU, there is quite a balanced contribution to the total number of publications 
between a range of countries: Denmark, Germany, France, the U.K. and Italy. When it comes to patenting Solid 
Oxide electrolysers, a considerable amount of activity is observed from Denmark, which seems to be focussing 
strongly in this area (specifically through the work of Haldor Topsoe). 

Figure 17: TIM plots showing the EU/World countries producing the most publications 
regarding SO electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

42 

(a) All documents (505)(b) Articles (324)(c) Patents (23)(a) All documents (1168)(b) Articles (708)(c) Patents (105) 
 
 
 
 
 
 
 
 
 
Figure 18: TIM Plots showing the EU countries producing the most publications regarding 
SO electrolysers 

Source: JRC(TIM) based on FCH 2 JU TIM Spaces, 2020. 

In summary, the data in the sections above would suggest that the EU as whole is contributing very strongly on 
the world-wide stage to the field of electrolyser research. With regards to research publications, the EU is strong 
in all three electrolyser technologies (in particular in PEM electrolysers), however this strength does not always 
convert into patents (in particular for alkaline electrolysis). However, the patents that are produced are more 
often “high value” patents than those produced in other geographical regions. 

43 

(a) All documents (425)(b) Articles (259)(c) Patents (24) 
 
 
 
 
 
 
6  Conclusions and Recommendations  

In this section, a series of recommendations will be made based on the conclusions from this analysis and the 
processes used to collate the data used in this report. This will include suggestions for future FCH JU calls for 
electrolyser technologies.  

Alkaline electrolyser: 

 

 

 

 

The main challenge with alkaline electrolysers seems to be flexibility of use with RES. This should be 
reflected  in  the  Programme  KPIs,  which  tend  to  deal  with  operation  under  nominal  (steady-state) 
operation. 

The programme could focus more on alkaline electrolysers for the industrial use of hydrogen, rather 
than looking at flexibility for which PEM is more suited. 

For future calls, the balance between looking at next generation AEL and the focus on upscaling needs 
to  be  made.  Funding  projects  dealing  with  game-changing  materials  or  components  could  be 
considered. 

Projects  working  with  alkaline  electrolysers  are  often  using  commercial  or  near-commercial 
technologies.  Considerable  relevant  data  is  therefore  not  submitted  to  the  TRUST  database  for 
commercial sensitivity reasons, making tracking progress more difficult. Wherever possible, this should 
be addressed. 

PEM electrolyser: 

In general, the work focussing on next generation PEMEL appears to be achieving (or progressing well towards) 
the specific MAWP targets.  

 

 

 

Future projects should consider the aspect of recyclability. This is of  particular relevance because of 
the platinum group metals used. In particular, recycling of iridium is known to be challenging. 

The relationships between KPIs (e.g. current density, degradation rate, catalyst loadings) need to be 
formalised when reporting. 

Future focus may need to be more on maintaining levels of efficiency and performance whilst reducing 
PGM levels, moving to higher pressures etc. 

  An  increase  in  operating  hours  (in  order  to  reduce  the  share  of  CAPEX  in  the  overall  cost)  will  be 

important to the success of the technology. 

44 

 
 
 
 
 
 
 
 
 
 
 
 
SO Electrolyser: 

  More longer term durability testing is required at system level and under realistic operating conditions. 

 

Targets  for  SO  electrolysers  should  be  separated  according  to  applications  (i.e.  reversible  and  co-
electrolysis targets should be separate). 

As the majority of the research undertaken regarding SOEL has been at a lower TRL level than for the other 
technologies,  the  project  targets  have  tended  to  be  somewhat  different  to  the  system  level  targets  for  the 
programme. Whether the programme level targets are addressed by future projects will depend on the approach 
of the FCH JU i.e. whether projects will be aimed more at scaling up of the technology or towards fundamental 
research. If the latter case, then additional targets at the stack rather than system level could be considered.  

General approach: 

 

 

 

In future calls, hydrogen for industry rather than hydrogen for HRS/mobility needs to be more greatly 
considered. In this case, scale is a major issue that needs to be addressed. 

For  industrial  hydrogen,  the  main  consideration  is  lowering  the  cost  of  H2.  SOEL  might  have  an 
advantage  as  they  could  have  steam  available.  Integration  with  the  relevant  environment  is  a  key 
challenge to tackle looking forward. 

The provision of grid services is considered to be a nice extra, however it should not be considered a 
business case in itself.  

45 

 
 
 
 
 
 
 
References 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

10. 

11. 

12. 

13. 

14. 

15. 

16. 

17. 

18. 

19. 

20. 

Fuel Cells and Hydrogen Joint Undertaking. Available from: https://fch.europa.eu/. 

Multi-Annual Work Plan 2014 - 2020; Fuel Cells and Hydrogen Joint Undertaking, 2014. Available 
from: https://www.fch.europa.eu/page/multi-annual-work-plan 

Davies,  J.C.,  Keyword  Analysis  and  Project  Classification  of  FCH  2  JU  Projects,  EUR  30187  EN, 
Publications  Office  of  the  European  Union,  Luxembourg,  2020,  ISBN  978-92-76-17296-3, 
doi:10.2760/527632, JRC119839. 

Addendum  to  the  Multi-Annual  Work  Plan  2014-2020  of  the  Fuel  Cells  and  Hydrogen  2  Joint 
Undertaking (FCH 2 JU), 2018. Available from: https://www.fch.europa.eu/page/multi-annual-work-plan 

Dincer, I. and C. Zamfirescu, Sustainable Hydrogen Production, Elsevier, 2016. 

Carmo,  M.  and  D.  Stolten,  'Chapter  4  -  Energy  Storage  Using  Hydrogen  Produced  From  Excess 
Renewable  Electricity:  Power  to  Hydrogen,  in  Science  and  Engineering  of  Hydrogen-Based  Energy 
Technologies.' Hydrogen Production and Practical Applications in Energy Generation. 2019. p. 165-199. 

Carmo, M., et al., 'A comprehensive review on PEM water electrolysis.' International Journal of Hydrogen 
Energy, Vol. 38, 2013, pp. 4901-4934. 

Nel  Hydrogen 
https://nelhydrogen.com/assets/uploads/2017/01/Nel_Electrolyser_brochure.pdf. 

The  world’s  most 

Electrolyser: 

efficient 

and 

reliable 

electrolyser; 

Løkke,  J.A.,  Nel  Group,  2017;  Available  from:  https://www.fch.europa.eu/sites/default/files/S2.3-
J.A.L%C3%B6kke%2CNel.pdf. 

Proost, J., et al. 'Electrolysis: What are the investment costs? State of the art and outlook. (IEA Hydrogen 
- Task 38 Brief).' 2018;. 

Fuel  Cells  and  Joint  Undertaking  Programme  Review  Report  2017;  Available 
https://www.fch.europa.eu/programme-review-page/programme-review-report-2017, 2018. 

from: 

Bessarabov, D. and P. Millet, PEM Water Electrolysis Hydrogen and Fuel Cells Primers, ed. B.G. Pollet. 
Vol. 1. Academic Press (Elsevier), 2018. 

Posters - FCH JU PRD 2018. Available from: 
https://www.fch.europa.eu/sites/default/files/5%20%28ID%204907120%29.pdf. 

Pandiyan,  A.,  et  al.  'Review  of  solid  oxide  electrolysis  cells:  a  clean  energy  strategy  for  hydrogen 
generation.' Nanomaterials and Energy.  Vol. 8, 2019, pp. 2-22. 

Eguchi,  K.,  T.  Hatagishi,  and  H.  Arai,  Power  generation  and  steam  electrolysis  characteristics  of  an 
electrochemical cell with a zirconia- or ceria-based electrolyte.' Solid State Ionics, Vol 86-88, 1996, pp. 
1245–9. 

Hauch, A., et al., J. Electrochem. Soc., Vol 153, 2006, pp. A1741–A1747. 

Osada, N., H. Uchida, and M. Watanabe, J. Electrochem. Soc., Vol. 153, 2006, pp. A816–A820. 

Laguna-Bercero, M.A., S.J. Skinner, and J.A. Kilner, Journal of Power Sources, Vol. 192, 2009, pp. 126–
131. 

Ishihara,  T.,  H.  Matsuda,  and  Y.  Takita,  'Doped  LaGaO3  perovskite  type  oxide  as  a  new  oxide  ionic 
conductor' J Am Chem Soc, Vol 16, 1994, pp. 3801–3. 

Van  Herle,  J.,  et  al.,  'Low  temperature  fabrication  of  (Y,Gd,Sm)-doped  ceria  electrolyte.'  Solid  State 
Ionics, Vol 86-88, 1996, pp. 1255–8. 

46 

 
 
 
 
 
21. 

22. 

23. 

24. 

25. 

26. 

27. 

28. 

29. 

30. 

31. 

32. 

33. 

Thangadurai, V. and P. Kopp, 'Chemical synthesis of Ca-doped CeO2-intermediate temperature oxide 
ion electrolytes.' J Power Sources, Vol 168, 2007, pp. 178–83. 

Sunfire - Products and Technology. Available from: https://www.sunfire.de/en/products-and-technology. 

mPower Products and Technology. Available from: 
http://www.mpowergmbh.de/productandtechnology.html#soec. 

OxEon Energy - Custom Solutions. Available from: https://oxeonenergy.com/custom-solutions. 

Sunfire - Hylink Unit. Available from: https://www.sunfire.de/en/products-and-technology/sunfire-hylink. 

Press Release: SOLIDpower S.p.A. - Breakthrough in solid oxide electrolyser durability. Available from: 
https://www.fch.europa.eu/sites/default/files/PRESS%20RELEASE%20SOE-stackdurablity-
SOLIDpower.pdf. 

Choi, S., T.C. Davenport, and S.M. Haile, 'Proton ceramic electrochemical cells for hydrogen production 
and  electricity  generation:  exceptional  reversibility,  stability,  and  demonstrated  faradaic  efficiency.' 
Energy Environ. Sci., Vol. 12, 2019. p. 206. 

Yoo, Y. and N. Lim, J. Power Sources, Vol. 229, 2013, pp. 48-57. 

https://www.mn.uio.no/smn/english/research/projects/chemistry/electra/index.html 

https://www.sintef.no/projectweb/gamer/ 

Fiorini, A., et al., Monitoring R&I in Low-Carbon Energy Technologies. EUR 28446 EN, Publications Office 
of the European Union, Luxembourg. ISBN 978-92-79-65591-3, doi: 10.2760/434051, 2017. 

Cooperative Patent Classification; European Patent Office / United States Patent and Trademark 
Office. Available from: 
http://www.cooperativepatentclassification.org/cpcSchemeAndDefinitions/table.html  

Nel  Press  Release:  Acquires  Proton  OnSite  to  create  the  world’s  largest  electrolyser  company  and 
launches  private  placement.  2017;  Available  from:  https://nelhydrogen.com/press-release/acquires-
proton-onsite-to-create-the-worlds-largest-electrolyser-company-and-launches-private-placement/. 

47 

 
 
 
 
 
 
List of abbreviations and definitions 

AC 

AEL 

BoP 

Alternating Current 

Alkaline Electrolyser 

Balance of Plant 

CAPEX 

Capital Expenditure 

CEA 

CPC 

DLR 

DTU 

EPO 

EC 

EU 

FC 

FCEV 

FCH 

Commisariat à l'Energie Atomique 

Cooperative Patent Classification 

DLR means Deutsche Forschungsanstalt fur Luft-und Raumfahrt (German Aerospace Centre) 

Denmark Technical University 

European Patent Office 

European Commission 

European Union 

Fuel Cell 

Fuel Cell Electric Vehicle 

Fuel Cells and Hydrogen 

FCH JU 

Fuel Cells and Hydrogen Joint Undertaking 

FCH 2 JU   

Fuel Cells and Hydrogen 2 Joint Undertaking  

FP7 

H2020 

Framework Programme 7 

Horizon 2020 

HER 

HHV 

HRS 

HTE 

ITSE 

JRC 

KPI 

LCA 

LCI 

LHV 

LSM 

MAWP 

MEA 

O&M 

Hydrogen Evolution Reaction 

Higher Heating Value 

Hydrogen Refueling Station 

High Temperature Electrolysis 

Intermediate Temperature Steam Electrolysis 

Joint Research Centre of the European Commission 

Key Performance Indicator 

Life Cycle Analysis 

Life Cycle Inventory 

Lower Heating Value 

Lanthanum Strontium Manganite 

Multi-Annual Work Program 

Membrane Electrode Assembly 

Operational and Maintenance (Costs) 

48 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
OER 

PAE 

Oxygen evolution reaction 

Pressurised Alkaline Electrolyser 

PATSTAT   

European Patent Office Worldwide Patent Statistical Database 

PCEC 

PCEL 

PEM 

Proton Ceramic Electrolyser Cell 

Proton Ceramic Electrolyser 

Proton Exchange Membrane 

PEMEL 

Proton Exchange Membrane Electrolyser 

PGM 

PoC 

PRD 

R&D 

RES 

rSOC 

ScSZ 

SINTEF 

SMR 

SO 

SOEL 

SOEC 

SOFC  

SoA 

TIM 

TRL 

Platinum Group Metal 

Proof of Concept 

Programme Review Day 

Research and Development 

Renewable Energy Sources 

Reversible Solid Oxide Cell 

Scandia-stabilised zirconia 

Selskapet for INdustriell og TEknisk Forskning ved norges tekniske hoegskole (The Foundation 
for Scientific and Industrial Research at the Norwegian Institute of Technology) 

Steam Methane Reforming 

Solid Oxide 

Solid Oxide Electrolyser 

Solid Oxide Electrolyser Cell 

Solid Oxide Fuel Cell 

State of (the) Art 

Tools for Innovation Monitoring 

Technology Readiness Level 

TRUST 

Technology Reporting using Structured Templates 

UK 

US 

YSZ 

United Kingdom 

United States 

Yttria-stabilised zirconia 

49 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
List of figures 

Figure 1: Cumulative level of FCH JU funding versus project start year for electrolyser technologies .......... 5 

Figure 2: TIM plots showing (a) the participants for Panel 5 projects considered in this report.; (b) EU member 
state participation for Panel 5 projects considered in this report. .................................................. 6 

Figure 3:  Energy Consumption versus System Power for a range of commercially available alkaline 
electrolysers ............................................................................................................ 8 

Figure 4: Electrical Energy Consumption calculated from the Rated and Experimental System Electrical 
Efficiencies for Alkaline Electrolysers. SoA and Targets shown are the FCH JU values from 2017. ............10 

Figure 5: Energy Consumption versus System Power for a range of commercially available PEM electrolysers
 ..........................................................................................................................16 

Figure 6: Electrical Energy Consumption calculated from the Rated and Experimental System Electrical 
Efficiencies for PEM Electrolysers. SoA and Targets shown are the FCH JU values from 2017. ................19 

Figure 7: System Electrical Energy Consumption calculated from the Rated and Experimental System 
Efficiencies provided in TRUST (all projects, all years of TRUST) for SO Electrolysers ...........................28 

Figure 8: Number of patent families filed versus country/region code for the tags Y02E 60/366 and Y02E 
70/10 from 2000-2014...............................................................................................37 

Figure 9: Number of patent families filed to the EU-28 countries for the tag Y02E 60/366 and Y02E 70/10 
from 2000-2014 ......................................................................................................37 

Figure 10: Number of patent families filed per year for the tag Y02E 60/366 from 2000-2014 ..............38 

Figure 11: Sankey diagram showing the flow of inventions by geographical region (for 2000-2014). ........39 

Figure 12: Leading organisations with filed patent families in the electrolyser field (for 2000-2014). ........39 

Figure 13: TIM plots showing the EU/World countries producing the most publications regarding alkaline 
electrolysers ...........................................................................................................40 

Figure 14: TIM Plots showing the EU countries producing the most publications regarding alkaline electrolysers
 ..........................................................................................................................41 

Figure 15: TIM Plots showing the EU countries producing the most publications regarding alkaline electrolysers
 ..........................................................................................................................41 

Figure 16: TIM Plots showing the EU countries producing the most publications regarding PEM electrolysers 42 

Figure 17: TIM plots showing the EU/World countries producing the most publications regarding SO 
electrolysers ...........................................................................................................42 

Figure 18: TIM Plots showing the EU countries producing the most publications regarding SO electrolysers ..43 

50 

 
 
 
 
 
List of tables 

Table 1: Programme Review Day Panels – Names and Topics ...................................................... 3 

Table 2: MAWP objectives and achievements for hydrogen production from renewable electricity for energy 
storage and grid balancing using alkaline electrolysers [4] ........................................................13 

Table 3: MAWP objectives and achievements for hydrogen production from renewable electricity for energy 
storage and grid balancing using PEM electrolysers [4] ............................................................23 

Table 4: MAWP objectives and achievements for hydrogen production from renewable electricity for energy 
storage and grid balancing using high-temperature SOEL [4] .....................................................31 

Table 5: Explanation of the patent classification hierarchy for Y02 60/366 & Y02E 70/10 .....................36 

Table 6: Summary of Projects in this Report ........................................................................52 

51 

 
 
 
 
 
 
 
Annexes: Summary of Projects reviewed for this Report 

Table 6: Summary of Projects in this Report 

Technology 

Project  

Panel 

Start/End  

Project Title and Summary of original Project Objectives 

AEL 

RESELYSER 

5 

2011-2015 

Hydrogen  from  Renewable  Energy  Sources:  pressurised  alkaline 
electrolyser with high efficiency and wide operating range. 

ELYGRID 

5 

2011-2014 

Improvements  to  integrate  high  pressure  alkaline  electrolysers  for 
electricity/H2 production from renewable energies to balance the grid 

ELYNTEGRATION 

5 

2015-2018 

Grid  Integrated  Multi  Megawatt  High  Pressure  Alkaline  Water 
Electrolysers for Energy Applications 

DEMO4GRID 

CHIC 

MOBYPOST 

JIVE 

AEL/PEMEL 

DON QUICHOTE 

QUALYGRIDS 

HYFIVE 

H2ME 

REMOTE 

PEM 

PRIMOLYZER 

NEXPEL 

NOVEL 

5 

1 

1 

1 

5 

5 

1 

1 

3 

5 

5 

5 

2017-2022  Demonstration of 4MW Pressurized AEL for Grid Balancing Services 

2010-2016 

Clean Hydrogen in European Cities 

2011-2015  Mobility with Hydrogen for Postal Delivery 

2017-2022 

Joint Initiative for hydrogen Vehicles across Europe 

2012-2018  Demonstration  Of  New  Qualitative  Innovative  Concept  of 

Hydrogen Out of windTurbine Electricity 

2017-2020  Standardized Qualifying tests of electrolysers for grid services 

2014-2018  Hydrogen for innovative vehicles 

2015-2020  Hydrogen Mobility Europe 

2018-2021  Remote area Energy  supply  with  Multiple Options for  integrated 

hydrogen-based Technologies 

2010-2012 

PRessurIzed PEM electrOLYZER 

2010-2012  Next-Generation PEMEL for Sustainable Hydrogen Production  

2012-2016 

Novel  materials  and  system  designs  for  low  cost,  efficient  and 
durable PEM electrolysers. 

ELECTROHYPEM 

5 

2012-2015 

Enhanced performance and cost-effective materials for long-term 
operation of PEM water electrolysers coupled to renewable power 
sources. 

MEGASTACK 

HYBALANCE 

HPEM2GAS 

5 

5 

5 

2014-2017  Stack design for a Megawatt scale PEM electrolyser. 

2015-2020  HyBalance 

2016-2019  High  Performance  PEM  Electrolyzer  for  Cost-effective  Grid 

Balancing Applications 

52 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Technology 

Project  

Panel 

Start/End  

Project Title and Summary of original Project Objectives 

PEMEL 

BIG HIT 

5 

2016-2021  Building  Innovative  Green  Hydrogen  systems  in  an  Isolated 

Territory: a pilot for Europe 

ELY4OFF 

5 

2016-2019 

PEM  ElectroLYsers  FOR  operation  with  OFFgrid  renewable 
installations 

H2FUTURE 

5 

2017-2021  Hydrogen  Meeting  Future  Needs  of  Low  Carbon  Manufacturing 

Value Chains  

HAEOLUS 

5 

2018-2020  Hydrogen-aeolic energy with optimised electrolysers upstream of 

substation 

PRETZEL 

NEPTUNE 

REFHYNE 

H2ME 2 

ZEFER 

PHAEDRUS 

5 

5 

5 

1 

1 

2 

2018-2020  Novel  modular  stack  design  for  high  pressure  PEM  water 
electrolyzer  technology  with  wide  operation  range  and  reduced 
cost 

2018-2021  Next Generation PEM Electrolyser under New Extremes 

2018-2022  Clean Refinery Hydrogen for Europe 

2016-2022  Hydrogen Mobility Europe 2 

2017-2022  Zero Emission Fleet vehicles For European Roll-out 

2012-2015 

High  pressure  hydrogen  all  electrochemical  decentralized 
refueling station 

SOEL 

ADEL 

5 

2011-2013  Advanced  Electrolyser  for  Hydrogen  Production  with  Renewable 

Energy Sources 

SOPHIA 

HELMETH 

SELYSOS  

ECO  

GRINHY  

5 

5 

5 

5 

5 

2014-2017  Solar integrated pressurized high temperature electrolysis (HTE) 

2014-2017 

Integrated  High-Temperature  electrolysis  and  methanation  for 
effective power to gas conversion 

2015-2019  Development  of  new  electrode  materials  and  understanding  of 
degradation  mechanisms  on  Solid  Oxide  High  Temperature 
Electrolysis Cells. 

2016-2019  Efficient Co-Electrolyser for Efficient Renewable Energy Storage  

2016-2019  Green  Industrial  Hydrogen  via  Reversible  High-Temperature 

Electrolysis 

REFLEX  

5 

2018-2020  Reversible solid oxide Electrolyzer and Fuel cell for optimized Local 

Energy miX 

GRINHY 2.0  

PCEL 

ELECTRA 

GAMER 

5 

5 

5 

2019-2022  Green Industrial Hydrogen via steam electrolysis 

2014-2017  High temperature electrolyser with novel proton ceramic tubular 
modules of superior efficiency, robustness, and lifetime economy 

2018-2020  Game changer in high temperature steam electrolysers with novel 
tubular  cells  and  stacks  geometry  for  pressurized  hydrogen 
production 

Source: JRC, based on information from FCH 2 JU, 2020. 

53 

 
 
 
 
 
 
 
 
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doi:10.2760/951902 

ISBN 978-92-76-32441-6