Energy is a key element of the sustainable interactions between nature and society, and it is considered a key input for economic development. It has an environmental impact that spans a continuously growing range of pollutants, hazards, and eco-system degradation factors, which affect areas from local through regional to global levels. Some of the major concerns arise from observable, chronic effects on, for instance, human health and economic growth, while others stem from actual or perceived environmental risks, such as possible accidental releases of hazardous materials, to an increasing number of natural disasters (e.g. hurricanes, droughts). Many environmental problems are caused by or related to the production, transformation, transportation, distribution, conversion, and consumption of energy. Some well-known examples include acid rain, stratospheric ozone depletion, and global climate change.
Green energy is regarded as an essential element for energy security, sustainable development, and social, technological, industrial, and governmental innovations in a country. An increase in the green energy consumption of a country often provides a positive impact on economic growth and social development. Of course the use of fossil fuels has also resulted in economic growth and social development since industrial revolution, but it exerted a heavy toll on the environment. Moreover, the supply and utilization of low-priced green fuel is particularly significant for global stability, since energy plays a vital role in industrial and technological development around the world. Green energy, the form and utilization of energy that has no or minimal negative environmental, economic, and societal impact, is essential to achieve the ultimate goal of sustainable, and may be better achieved through energy diversity with local energy resources, such as solar, hydro, biomass, wind, geothermal, and other renewable resources. Green energy can be utilized to reduce the negative effects of hydrocarbon energy resources and their emissions during power generation, especially greenhouse gases. It provides an important option for meeting clean energy demand for both industrial and non-industrial applications. Green energy is consequently a major factor in future sustainable development and world stability.
There are 11 papers in this special Green Energy issue of IJER that cover a range of topics such as green thermodynamics, sustainability, hydrogen economy, greenhouse gas reductions, innovative solar collectors, and mapping of wave energy resources. These papers are selected from the papers presented at the 2nd International Green Energy Conference (IGEC-2) at the University of Ontario, Institute of Technology, Oshawa, Ont., Canada, 25-29 June 2006, which was a multi-disciplinary conference on the production, application, and use of environmentally friendly and sustainable energy. We hope that this special issue of IJER will increase the awareness on green energy, and attract more attention to this important topic.