Decarbonisation strategies based on whole energy system analysis are critical in the transition to a low carbon economy. Energy system integration is attracting increasing interest across scales, and scenarios show how electricity, heat and transport fuels are likely to become ever more interlinked in sustainable transitions. At the same time, whilst energy policy is largely determined centrally by the UK government, devolved and decentralised energy systems are emerging driven by technology developments and local priorities. However, policies which impact the use and supply of energy (including non-energy policies), and the related infrastructure, are dispersed across government departments and many other organisations at each level of governance, from local to national to transnational. These policies are proving to be critical to driving large-scale public and private sector investment in the energy system, with recent policy changes having been observed to damage investor confidence.

This scoping study will analyse how whole energy system analysis is currently used in decision-making processes across scales, and identify ways in which the research - policy - decision-making relationship could be improved in the future. We will consider the key whole-system models and tools being used, their perceived value and limitations in representing the energy system across scales, the key channels for research-policy linkages, and how the model outputs are actually used in practice.

Fundamentally, we will challenge the assumption that there is simply a 'model deficit' - i.e. that 'better' models would give better evidence, leading to better decisions and outcomes. Rather, we expect a complex interplay between the modelling, supporting research and the decision-making processes - a complexity which is especially acute when considering the multi-scalar landscape of the energy system. We must also reflect that whole energy system models should not only be developed to meet short term policy needs within an existing or anticipated paradigm, but can be tools to explore alternative futures over the longer term.

We propose a novel approach to mapping the science-policy interface of whole energy system analysis across scales. By assessing this complexity in a scoping study we can begin to address the factors that are limiting the value of whole energy system modelling to decision makers across scales, and guide future work to propose ways in which the value can be increased through improvements both to the models and decision-making processes. We will examine:

- processes of collaboration and exchange between actors using the models in the decision-making process, within and between scales. We will conduct preliminary case studies of policy formation and the role of modelling at UK, Scottish and an exemplar city scales (Birmingham and Leeds), covering policy-makers, the modelling community, intermediaries and the role of other stakeholders. This will allow us to describe the complexity that exists in decision making processes and compare/contrast the different case studies.

- how whole systems models at different scales (international, national, local) could be more effectively integrated or reconciled, and what additional insights this would provide. We will identify promising research opportunities that may arise from developing multi-scale tools (and/or linking tools across scales) and representing new technologies that will have an impact on the energy system at different scales.

Potential Impact:
Our aim is to engage with stakeholders to understand the reality of decision making informed by whole energy system modelling and analysis at different scales. To further this aim, we have already engaged with, and received nine formal Letters of Support for the proposed project. These individuals are very positive about the potential impacts of the study, seeing its relevance to their work, and have agreed to participate, offering time and information.

We have chosen to take a thematic focus on heat, which is now an area of central concern in UK energy futures, but also of considerable uncertainty. This will give us an opportunity to draw specific (though initial) conclusions from our analysis, to inform the work of policy-makers, modellers and intermediary organisations.

People
Our intent is to draw on expertise, and also to build collaborative networks that would last beyond the length of the study as part of a follow-up project, or to be self-sustaining where participants see value in learning from the experiences of others.
In developing our outputs, we will collaborate with the UK's energy research community (through key interdisciplinary research centres including UKERC and CESI), intermediary and advisory organisations working at the research-policy interface (such as the UK Committee on Climate Change and ClimateXChange) and directly with policy, research strategy and other bodies.
Our workshop activities will promote interaction between actors and organisations across different scales.

Knowledge
Academic impact will be pursued through at least two papers for publication in leading disciplinary and interdisciplinary journals. As well as these generic outputs, more context-specific outputs will include reports summarising the results of our Edinburgh and London workshops. The final synthesis report will bring together generic and context-specific insights and identify recommendations for further research.
We will also draw on our links with established interdisciplinary whole systems research centres such as UKERC and CESI, to position our findings within the UK's expanding portfolio of whole systems research, and how our scoping insights could be taken forwards to best complement other research efforts sponsored by the Energy Systems Catapult and EPSRC.

Society
Short (maximum 4 page) Policy Briefing Notes will be prepared on (i) model-linking across domains and scales and (ii) expert participation and elicitation methods. These will be disseminated through our website and other channels.
For policymakers in terms of improved understanding of whole energy system and infrastructure change, we will engage with the policy teams across scales.

Economy
Our study aims to improve decision making across scales, such that investments can be made in energy infrastructure that allow a cost-effective transition to low carbon. An Energy Technologies Institute (ETI) report found a difference of > £10bn/yr in expenditure needed to meet climate change targets, depending on whether there was a centrally coordinated or regionally fragmented energy strategy. To secure wider business and research impact we will seek to present our findings at high-profile industry and academic conferences hosted by key organisations.

Delivery of impact
One important mechanism to enable impact will be through our Project Advisory Group (PAG).
We will create a project website, to publish project findings, blogposts and publicise related activities at partner institutions and elsewhere. We will also offer guest blogposts and comment articles to UKERC, the Energy Systems Catapult and others.
For policy, business and research impact, we will work with the Energy Systems Catapult to identify specific opportunities for impact. For example, we will offer to host a Catapult webinar for business, researchers and other stakeholders.