Volume 2 Issue 12, December 2017

Although nearly all 2 °C scenarios use negative CO₂ emission technologies, only relatively small investments are being made in them, and concerns are being raised regarding their large-scale use. If no explicit policy decisions are taken soon, however, their use will simply be forced on us to meet the Paris climate targets.

Millions of refugees need heat and light, but many barriers prevent its sustainable supply.

It is challenging to unlock anionic redox activity, accompanied by full utilization of available cationic redox process, to boost capacity of battery cathodes. Now, material design by tuning the metal–oxygen interaction is shown to be a promising solution.

Understanding individual energy use can inform interventions for energy conservation. A longitudinal qualitative interview study shows that energy use behaviour is not simply a matter of individual choice, but rather is influenced by unique personal circumstances and familial and social relationships, which change over time.

Hydropower represents about 20% of sub-Saharan electricity, and expansion is underway. Rainfall varies year-to-year in geographical clusters, increasing the risk of climate-related electricity supply disruption in dry years.

A policy sequence for low-carbon policy that is politically effective continues to face challenges of environmental and cost effectiveness. This Perspective outlines ways to address these issues within political constraints.

Hydrogen is mainly produced industrially via steam methane reforming, a multistage process carried out in large plants to minimize energy losses and costs. Here, by exploiting thermal integration in a protonic membrane reformer, the authors produce compressed hydrogen in a single step with high efficiency.

CO₂ is often found alongside CH₄ in natural gas wells; therefore, separation of the gases is an important industrial process. Jalilov et al. demonstrate that the adsorption selectivity for CO₂ over CH₄ can be significantly enhanced through introduction of water into the pores of a high-surface-area carbon.

All energy generation technologies emit greenhouse gases during their life cycle as a result of construction and operation. Pehl et al. integrate life-cycle assessment and energy modelling to analyse the emissions contributions of different technologies across their lifespan in future low-carbon power systems.

Hydropower is critical to eastern and southern Africa but it is at risk from climate variability. Conway et al. examine river basins and rainfall variability to explore potential hydropower disruption for present and planned generation sites, highlighting the risks to supply and their spatial interlinkages.

Anionic redox provides extra capacity for battery electrodes, but it is challenging to realize its full potential. Tarascon and colleagues report a record-high reversible capacity of 3.5 electrons per Ir in a Li₃IrO₄ phase, and discuss the importance of increasing the ratio of oxygen versus transition metal.

It is challenging to exploit anionic redox activity to boost performance of battery electrodes, especially for anti-fluorite structures. Here the authors report simultaneous anionic and cationic redox in Li₅FeO₄, which enables its high capacity and eliminates the undesired oxygen gas release.

Cation engineering has been used to tune the efficiency and stability of perovskite solar cells. Here, Jodlowski et al. introduce guanidinium, a cation slightly larger than previously thought possible, mixed with the traditional methylammonium cation, into the 3D structure, improving device stability.