Feature Article

Success at the latest climate talks will be a recognition by the world’s nations that incremental change will not do the job, says Johan Rockström.

Leaders must come together on a solid agreement at the United Nations climate conference — and then get to work at home by meeting commitments and finding new ways to reduce emissions. (Editorial)

Original Source

Exports of pellets from the United States(US) are growing significantly to meet the demand for renewable energy in the European Union. This transatlantic trade in pellets has raised questions about the greenhouse gas(GHG)intensity of these pellets and their effects on conventional forest product markets in the US. This paper examines the GHG intensity of pellets exported from the US using either forest biomass only or forest and agricultural biomass combined.

Direct catalytic conversion of ethanol to hydrocarbon blend-stock can increase biofuels use in current vehicles beyond the ethanol blend-wall of 10–15%. Literature reports describe quantitative conversion of ethanol over zeolite catalysts but high C2 hydrocarbon formation renders this approach unsuitable for commercialization. Furthermore, the prior mechanistic studies suggested that ethanol conversion involves endothermic dehydration step.

Regardless of the harmful effects of burning fossil fuels on global climate other energy sources will become more important in the future because fossil fuels could run out by the early twenty-second century given the present rate of consumption. This implies that sooner or later humanity will rely heavily on renewable energy sources. Here we model the effects of an idealized large-scale application of renewable energy on global and regional climate relative to a background climate of the representative concentration pathway 2.6 scenario.

The UK government’s decision to subsidize a nuclear power station while cutting support for renewables is short-sighted. (Editorial)

Original Source

Concentrated solar power (CSP) plants have invited wide attention in various sunlight-rich regions around the world, including India. Under sponsorship of the Ministry of New and Renewable Energy, Government of India, the Indian Institute of Technology Bombay, Mumbai has conceptualized and carried out the basic engineering design, installation, commissioning and operation of a 1 MW(e) CSP plant on the campus of the National Institute of Solar Energy at Gwalpahari, near Gurgaon, Haryana, India.

In December, national delegations from almost 200 nations will meet in Paris to hammer out an agreement on greenhouse gas emission (GHG) reductions. Like Kyoto (1997) and Copenhagen (2009) before it, Paris 2015 will rely on GHG emission reduction pledges to achieve their climate goals, this time to limit global warming to less than 2 °C.

Original Source

The present article discusses the application of a new technology using solar photovoltaic (PV) cell coupled with membrane distillation (MD) in the desalination of tap water. Salinity decreases the palatibility of water and causes long-term health issues. MD is the most promising technology to provide safe and clean drinking water to households and for other applications in small quantities. It consumes less energy than the existing commercial brackish water reverse osmosis (RO; pressure-driven) desalination technology (48%) used for the production of drinking water.

Nontransparent contact fingers on the sun-facing side of solar cells represent optically dead regions which reduce the energy conversion per area. We consider two approaches for guiding the incident light around the contacts onto the active area. The first approach uses graded-index metamaterials designed by two-dimensional Schwarz–Christoffel conformal maps, and the second uses freeform surfaces designed by one-dimensional coordinate transformations of a point to an interval.