Comment by Daniel Murrant, Networks and Energy Storage Lead, at Energy Systems Catapult.

There is increasing acceptance that hydrogen has a part to play in the Net Zero energy system to support flexibility. Despite this, there is still significant uncertainty about the scale, timing, technology and specific role, or roles, for hydrogen within a Net Zero energy system. As part of its mission to accelerate the development of critical hydrogen technologies and supply chains in the UK, the IUK-funded Hydrogen Innovation Initiative (HII) Seed project aims to help reduce these uncertainties.

One way to explore this further is through energy system models, which can be used to help inform stakeholders and decision makers about how parts of, or an entire, energy system may evolve, the factors which drive this and key uncertainties that may impact any future change.

There are a wide range of energy system models available each with their own set of characteristics, from the parts of the energy system and the energy vectors (including hydrogen) they model to the timeframes they explore and how they handle uncertainty. This means that some models will be more, or less appropriate to use for any given type of analysis.

In light of this a comparison of available energy system models has been undertaken. Each of these models have been used to model at least part of the UK energy system, and they have been assessed against a set of key characteristics, including whether they could represent hydrogen. It is intended for this assessment to be used in two ways:

• To support the wider UK hydrogen industry to understand the types of analysis that can be carried out to shed light on the role of hydrogen in a future UK energy system.
• To assist those modelling hydrogen within the UK energy system, to select the model (or models) most suited to their purpose.

To do this, three documents have been produced (which can be found below):

• A set of visualisations which provide a clear and easy-to-access visual summary of each model against some of the key characteristics assessed. These visualisations are split into those which highlight the part of the energy system assessed by each model (for example which energy vectors are modelled, and over what timeframe), and more modelling-specific considerations such as whether an optimisation or simulation approach is used. They are also further broken down into those models which consider hydrogen, and for completeness those which were reviewed but do not represent hydrogen.

• A methodology report detailing the methodology used to identify these models and produce the spreadsheet and visualisations, as well as the characteristics they were assessed against.

• Model characteristic tables which summarise the models reviewed and their key characteristics. There is a focus on those models which can represent hydrogen; although to provide context and allow comparison, models which don’t represent hydrogen are also included.

In total 88 models were reviewed, with 39 including a representation of hydrogen. Some of these models provide a detailed representation of hydrogen across the whole energy system while other focus on specific areas, for example hydrogen for energy storage or hydrogen distribution and transmission.

Figure 1 shows one of the visualisations produced, highlighting the models which represent hydrogen (darker green), alongside an example of some of the key energy system areas they consider.

It is hoped that these outputs will contribute to accelerating the growth of the UK hydrogen sector by helping the industry to understand the types of results and analysis different models can provide. They will also provide a tool to assist those modelling hydrogen within the UK energy system, to compare and select the model(s) most suited to their purpose. These outputs are not an exhaustive list of all energy system models but rather provide a starting point for those looking to model hydrogen within the UK.