Ideal photoelectrochemical systems for hydrogen production should be highly efficient, stable and scalable. Here the authors report that a perovskite-based system with promising efficiency and stability can be scaled to cells of several square centimetres in area as well as formed into mini-modules with overall area >100 cm².

Geologic formations could be used for hydrogen storage and conversion to methane, yet technical feasibility is unclear as field-scale data are lacking. Here the authors perform field tests demonstrating that hydrogen can be stored and microbially converted to methane in a depleted underground hydrocarbon reservoir.

Development ramifications of global decarbonization efforts for fossil fuel-producing low and lower–middle income countries remain underexplored. This Perspective suggests three transition pathways for navigating these ramifications.

Decision makers need sector-specific, policy-focused, dynamic economic models with rich representations of technological progress. These allow them to understand how the energy transition is likely to unfold with different policies and what its impacts might be. A new generation of models is emerging to meet these demands, but more action is needed.

A new study finds that strategically integrating floating solar panels on reservoirs could substitute 20–100% of Africa’s planned hydropower by 2050. For the Zambezi watercourse, this approach generates a more stable electricity supply compared with hydro-dominated development.

Global climate models are challenging to integrate in energy system models because their output data resolution is too coarse. Buster et al. generate high-resolution meteorological data with climate change impacts from global climate model datasets using generative machine learning.

Electrolyte design strategies for lithium batteries rely on tailoring the composition of lithium–electrolyte interphases. Here lithium oxide is shown to be a key component of these interphases, making oxygenation an effective approach to achieve high efficiency.

Capacity is often used to evaluate and monitor battery state and health. Now, lithium inventory transactions can be accurately tracked at the electrode–electrolyte interface to improve battery performance and reliability.

Wide-bandgap perovskite solar cells suffer from phase segregation. Zhang et al. show that thiocyanate ions overcome the issue by occupying iodide vacancies while regulating crystallization, enabling perovskite/organic tandem cells with 25.06% efficiency.

Understating degradation pathways is critical to the development of perovskite photovoltaics. Thiesbrummel et al. show that internal electric field screening induced by ion migration is a dominant contributor to the operational performance loss of perovskite solar cells.

Annemarie Purmer discusses the importance of a sharing and inclusive safety culture in the hydrogen sector.