Aqueous batteries, such as iodide/iodate-based ones, confront challenges due to their low energy densities. Here the authors utilize hetero-halogen electrolytes to enable fast multielectron transfer, yielding high-energy-density aqueous batteries.

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.

Pay-as-you-go energy systems are a promising market-based approach to paying for energy in small amounts in sub-Saharan Africa; however, implementation and the suitability of current business models show room for improvement. This Perspective outlines an agenda for more inclusive PAYG systems.

Recycling spent batteries is crucial for a circular battery economy, yet knowledge of solid-state battery (SSB) recycling lags behind that of lithium-ion batteries. This study evaluates SSB recycling techniques, emphasizing the need for specific, energy-efficient methods tailored to distinct electrolytes.

Elastocaloric cooling, an emerging refrigeration technology, has so far yielded limited performance in devices. Zhou et al. increase the temperature lift of such devices to 75 K by combining three NiTi elastocaloric materials with different phase-transition temperatures.

The US Midwest is a promising region for the production of cellulosic biofuel, yet a greater understanding of the interactions between landscape-related decisions, biorefinery design and carbon capture integration is still needed. O’Neill et al. use fine-scale spatially explicit modelling to analyse the cost and greenhouse gas mitigation potential for such fuels in this region.

Net energy implications of the energy transition have primarily been assessed at the final energy stage to date. New research considers the useful-stage energy return on investment and finds that wind and solar photovoltaics outperform fossil fuels, shedding light on their investment potential.

Interventions prioritizing care and knowledge in locally led energy transition initiatives may contribute to the disruption of established gender norms. A new study on the Solar Mamas programme in Zanzibar supports this idea.

Investment in climate and energy startups is growing in the United States. Here the authors show that public grants back high-risk areas, and that publicly funded startups exit at higher rates with corporate backing than with other private investment.

The European Commission has set a regulatory benchmark for classifying green hydrogen in the European Union. New research finds that by regulating the power purchase for electrolysers, emission savings from green hydrogen production is ensured, but cost is also affected.