Throughout RUGGEDISED, the Lighthouse Cities and their partners have worked on various cross-cutting themes centred on the energy transition. This has included work on +30 solutions, and the lessons learned and recommendations for others vary from solution to solution. One thing, however, being true across all the solutions is the need for strong partnerships, and the importance of working together both across different groups (public, private, academic and with citizens) and through different levels in each organisation. To offer practical advice on making this work, RUGGEDISED has produced thematic factsheets on four different themes.