Editorial

Abstract

Representatives from more than 190 countries participated in this conference. Although no important breakthrough was achieved, this conference attracted strong attention from the worldwide public and media, because it indicated the political willingness of the international community to reduce emissions of greenhouse gases in order to protect the environment.There are national and international programmes to reduce greenhouse gas emissions in the energy sector. In 2011, the European Commission issued the Energy Roadmap 2050 with the target to reduce carbon dioxide emissions down by 20% by 2050. Four different measures are considered to achieve this goal: energy efficiency, renewable energy, nuclear energy and carbon capture and storage (CCS). Rapid development of renewable energy is thus ongoing worldwide, especially since the nuclear accident in Fukushima, Japan. For example, in Germany, 80% of electricity will be produced by renewable energy by 2050.This issue contains five contributions with an emphasis on renewable energy. Two of them are devoted to wind energy, two papers to solar energy and one contribution to the 'lifecycle' approach for analysing greenhouse gas emissions.The first two papers are briefing articles, devoted to electrical energy storage options worldwide and the growth of wind power in Sweden, respectively. The briefing paper by Price (2014) provides an overview of battery energy storage technologies and their development. Various kinds of battery storage techniques are mentioned, such as the lead acid battery, lithium ion battery and high-temperature battery. The technical and economic challenges as well as some ongoing research projects are summarised.The wind energy programme in Sweden is summarised in the briefing paper by Kenrick (2014). Some of the driving factors for the development of wind energy are presented and discussed, such as electricity prices, electricity production prices using wind energy and job opportunities. In addition, the future wind energy programme of the IKEA group is presented.The envisaged levels of greenhouse gas emission reduction in some national and international programmes are, however, restricted only to one part of the entire life cycle, mostly direct energy production. The paper by Hammond and O'Grady (2014) describes the methodology to analyse greenhouse gas emissions on a life-cycle basis. The authors have performed extensive investigation and published their results in several previous publications. This paper gives an excellent summary of their research results. With the life-cycle approach, the greenhouse gas emissions both during the energy production phase and in the upstream procedures are considered. The authors confirm the importance of the life-cycle approach with two examples: methane leakage during the coal mining process and that from the gas pipeline. By considering the upstream procedures, greenhouse gas emission could be increased by about 20%. In addition, the authors analyse various scenarios in the UK and point out that the UK electr...