Africa Centre of Excellence for Sustainable Cooling and Cold Chain Systems (ACES)

ACES is one of the programmes coordinated by the Centre for Sustainable Cooling.  

Background to ACES

ACES is a first-of-its-kind Centre dedicated to sustainable, smart cold-chain, cooling and post-harvest management (PHM). The first ACES hub is being built in Kigali, hosted by the University of Rwanda. The hub will be a central point for research, data collection, training and demonstrations which branches out to specialised outreach centres in Africa including Community Cooling Hubs. The research examines the entire chain of food harvest, processing, storage and distribution, exploring sustainable, fit-for-market solutions and business models that benefit stakeholders at all levels of the value chain, ensuring quality and safety of food as well as improving prospects for smallholding farms in-country. Sustainable cold-chains are also vital for health purposes, including the management of national rollouts of vaccine distribution. 

In addition to the Rwanda hub, additional “SPOKE” projects are currently being planned throughout Africa to deploy and leverage ACES best practice in real-world settings; the first of these is currently being developed in Kenya.

The ACES programme is developed by the Governments of Rwanda and the United Kingdom (UK), the United Nations Environment Programme and the UK’s Centre for Sustainable Cooling leading a consortium of UK universities including HWU. Read more on the ACES website.

Our role in ACES

Heriot-Watt University’s role is focused on the strategic planning of cold chain investments for farm products and vaccines through computational modelling of such systems. These virtual models can not only help design the network, but assist in its day-to-day management. Decisions about interventions or significant changes to the network can be tested for different market trends and risks. This digital twin framework enables policymakers predict how best to future-proof investments, such as optimal locations of cold-chain infrastructure, to best achieve overall goals related to export targets or population health needs.

The simulations being developed by the HWU team use agent-based models (ABM). These self-organising systems allow decision-making algorithms access to cost structures, available technology options and logistics behaviour models. The model then chooses – automatically and rapidly - the most appropriate network arrangement that optimises for e.g. cost, carbon emissions, reduction of waste. A huge range of scenarios can thus be interrogated to appraise efficiency of future investment spend.

Examples of HWU ABM methodology already successfully deployed can be seen in these projects: 

For the ACES work, HWU has been building the software platform called MILES (Multimodal Integrated Logistics Environment for Simulation).

About HWU’s software platform MILES

MILES is Heriot-Watt’s package of algorithms and data structures for specialised whole-system modelling of logistics, developed within the UK as part of the Centre for Sustainable Road Freight (SRF) since 2019. Built on a data model structure that emphasises re-use across applications, MILES will be fundamental to ACES models of food and vaccine distribution and management.

Questions which MILES can help address in the context of ACES and the vaccine cold chain, which is also centrally planned and has existing logistics and supply chain data, include:

  • Can we use the model together with facility data to optimise an mRNA ultra-cold vaccine rollout on a national scale?
  • How best to position deep-freeze (-25c) and ultra-cold (-70c) facilities?
  • How to optimise delivery frequency and vehicle requirements?
  • How to deal with the next pandemic in terms of the network’s ability to cope with surges in specific demands?
  • Can the ultra-cold-chain network complement the existing distribution network for traditional vaccines?
  • What implications could there be for, e.g. drone deliveries?

The capability of MILES also extends to addressing urban delivery logistics, electric road system modelling and static charging, among notable applications.

On 20 April 2023, HM Government announced £1.2 million for the development of a roadmap and virtual modelling tools to help developing countries pilot techniques before they are implemented – enabling them to deploy the most efficient and cost-effective approach to more sustainable cooling. MILES is at the core of this work.

ACES Project Leads:

Professor Phil Greening, Heriot-Watt University
Professor Toby Peters, University of Birmingham and Heriot-Watt University

MILES Project Lead:

Dr Adam Gripton

MILES team members:



ACES Team in Edinburgh 

In Spring 2023, as part of a UK study tour, the ACES senior team from Rwanda, Kenya, UNEP and DEFRA spent a day with HWU and the MILES team in Edinburgh, hosted by HWU Principal Richard Williams with Prof. Toby Peters and Prof. Phil Greening. Read Richard Williams’s perspective in Keeping Cool. The delegation enjoyed working sessions with the HWU team in The National Robotarium: