Volume 1 Issue 4, April 2016

Solar power is increasingly economical, but its value to the grid decreases as its penetration grows, and existing technologies may not remain competitive. We propose a mid-century cost target of US$0.25 per W and encourage the industry to invest in new technologies and deployment models to meet it.

Waste heat can be converted to electricity by thermoelectric generators, but their development is hindered by the lack of cheap materials with good thermoelectric properties. Now, carbon-nanotube-based materials are shown to have improved properties when purified to contain only semiconducting species and then doped.

Public investment in science and technology is critical for meeting future energy needs, although understanding its impact has remained unclear. Now, an analysis of publications resulting from government funding sheds light on its outcomes and the timescales required to see them.

Doping graphitic materials is desirable to enhance their performance for energy conversion and storage applications, but achieving high dopant concentrations remains a challenge. Researchers now demonstrate synthesis of such materials with very high doping levels and facile tunability.

Materials with high ionic conductivity are urgently needed for the development of solid-state lithium batteries. Now, an inorganic solid electrolyte is shown to have an exceptionally high ionic conductivity of 25 mS cm⁻¹, which allows a solid-state battery to deliver 70% of its maximum capacity in just one minute at room temperature.

Tracking the Sun's motion in concentrating photovoltaics by rotating the whole system is impractical and hinders commercial deployment. Instead, integrated-tracking approaches, which are discussed in this Review, are more suitable for low-cost, rooftop applications.

Small-scale renewable energy systems and smart technologies are enabling energy consumers to become producers and service providers as well. This Perspective explores this ‘prosumption’ phenomenon, highlighting three promising prosumer market models and the challenges for future implementation.

The capture, storage and conversion of gases such as hydrogen, methane and carbon dioxide may play a key role in the provision of carbon-neutral energy. This Review explores the role of metal–organic frameworks — porous networks of metal ions or clusters connected by organic linkers — for such applications.

Government support for energy technology is vital, but quantifying its effects downstream is complicated. Towards this end, David Popp analyses scientific publication data resulting from public money, exploring the time lags between funding and new publications and the resulting policy implications.

The development of all-solid-state batteries requires fast lithium conductors. Here, the authors report a lithium compound, Li_9.54Si_1.74P_1.44S_11.7Cl_0.3, with an exceptionally high conductivity and demonstrate that all-solid-state batteries based on the compound have high power densities.

Organic thermoelectric materials are emerging as low-cost, versatile alternatives to more established inorganic ones. Avery et al. report carbon nanotube-based materials with selected properties that exhibit enhanced thermoelectric performance.

Controlling the surface of quantum dots has enabled higher efficiency in quantum dot solar cells. Now, the role of surface passivation and suppression of hydroxyl ligands in the performance and photostability of cells with an efficiency of 9.6% is unveiled.