This issue turns the focus on energy storage with guides on the top 20 technologies, understanding the costs involved and the how Germany is integrating it as part of its energy transition. We also look at the threat of cyber-attacks on solar plants, why there are still reasons to be cheerful about the large-scale European market and how one link of the US supply chain has clubbed together for a greater say in policy-making. Our regular technical papers cover climate stress on module degradation and the quest for accurate irradiance measurements and we get under the skin of West Africa's first utility-scale solar plant.