Joseph P. Heremans (Nature, 508, 327, 2014): Theremoelectricity: The Ugly Duckling.
The article is a commentary on a paper published in that issue of Nature on a record high figure of merit observed in a specific direction in a tin selenide (SnSe) single crystal. Along the way, we get a primer on the principle of ‘engines’ based on thermoelectrics, and the figure of merit, and challenges in pushing this metric up. Key sentence: “The goal of thermoelectric research is to discover new materials with maximum zT, by maximizing the ratio S2/ρ and minimizing ϰlat without increasing ρ” where S is the Seebeck coefficient, ρ is electrical resistivity and ϰlat is thermal conductivity due to lattice vibrations.
Richard Van Noorden (Nature 507, 26, 2014) The rechargeable revolution: A better battery. A nice overview of the kinds of ideas (and material systems) being considered for making better rechargeable batteries.
Jeff Tollefson (Nature 508, 302, 2014): Power from the oceans: Blue energy. An overview of different methods being implemented to harvest ocean energy (from tides as well as waves).