Volume 1 Issue 8, August 2016

Old dams on rivers are rapidly finding renewed purpose as sources of small-scale community-driven power.

The electronic properties of halide perovskites vary significantly between crystalline grains, but the impact of this heterogeneity on solar cell performance is unclear. Now, this variability is shown to limit the photovoltaic properties of solar cells, and its origins are linked to differing properties between crystal facets.

Energy-saving programmes are increasingly targeted at children to encourage household energy conservation. A study involving the assignment of energy-saving interventions to Girl Scouts shows that a child-focused intervention can improve energy-saving behaviours among children and their parents.

In the development of lithium–air batteries, managing the phase change between gaseous oxygen and crystalline lithium peroxide is a key challenge. Now, a high-performing sealed battery with an oxygen anion-redox electrode is presented that does not involve any gas evolution.

Electricity distribution system planners rely on estimations of future energy demand to build adequate supply, but these are complicated to achieve. An approach that combines spatially resolved projections of population movement and climate change offers a method for building better demand maps to mid-century.

Cheap energy can encourage economic growth but it can also force economies into specific energy-intensive futures. Roger Fouquet argues that path dependence in energy systems has profound implications for an economy and should be considered carefully before governments make choices about energy provision.

The photovoltaic properties of hybrid organic–inorganic perovskites are sensitive to the local microstructure, but difficult to quantify at the nanoscale. Leblebici et al. use conductive atomic force microscopy to map the local short-circuit current and open-circuit voltage, finding heterogeneity within individual grains.

A common problem for thick electrodes in lithium-ion batteries is slow ionic transport. Here, the authors present a particle-alignment method that uses a low magnetic field and show that the lithium diffusion path is improved for an aligned thick graphite electrode, leading to a better rate capability.

Behavioural interventions targeting children can influence the whole family, making them attractive for energy-saving schemes. Boudet et al. use 30 Girl Scout groups to test interventions on residential and food and transport energy behaviours and find they have potential for increasing energy saving.

Electrode materials with pores generally have high tortuosity, which is detrimental to battery performance. Here the authors develop a magnetic alignment approach that produces battery electrodes with low-tortuosity porosity and high capacity.

Future regional electricity demand will be affected by climate change and population migration. Allen et al. combine predictions of temperature rise and population shift, including in response to extreme weather, to map electricity demand and substation capability in the southern US to 2050.

The significant phase change between gaseous and crystalline oxygen deteriorates the performance of lithium–air batteries. Here the authors report a battery with a cathode consisting of Li₂O and Co₃O₄ nanocomposites, which displays stable cyclability and high energy density, without involving any gas evolution.