An Introduction to Design of Solar Water Heating Systems

Preface: The statistics are eloquent: water resources and supplies will become increasingly pressing issues in the face of climate change. What’s more, poor and vulnerable populations in developing countries are poised to take the brunt of the impact. With growing populations and increasing demands on water resources, these countries urgently need access to climate change adaptation options. But the options in themselves are not enough. Developing nations also need assistance in identifying which options are appropriate for which situation, and how to incorporate these measures into their climate change adaptation strategies. This book is a guide to the most relevant adaptation technologies and practices for the water sector in developing countries. In addition to descriptions and explanations, the guidebook outlines practical steps for implementing these technologies, illustrated with case studies. It not only lays out institutional and capacity building requirements, but also explores costs and other potential barriers to getting projects off the ground. Finally, the text is supplemented by a rich list of references to external sources and case studies. We hope that this comprehensive approach will make this book an effective tool that will prove useful to water sector policy makers and planners. But we also hope that it will serve as a valuable resource at the community level for village and district authorities, NGOs, and anyone else interested in the topic. This guidebook is co-authored by Mark Elliott, Andrew Armstrong, Joseph Lobuglio and Jamie Bartram at the Water Institute of the University of North Carolina, in Chapel Hill, USA, an institution dedicated to critical global issues in water and health. Its director, Prof. Jamie Bartram, is an internationally acknowledged expert in this area, and served as the chair of UN Water from 2004 to 2006. Thanakvaro De Lopez of the UNEP Risø Centre on Energy, Climate and Sustainable Development (URC) coordinated the guidebook’s production. Sergios Santos, Director of Terrasystemics and an expert on adaptation planning with focus on Africa LDCs and small island states, and Sau Sisovanna, senior lecturer in climate change planning at the National University of Cambodia, provided many important comments and suggestions. Their inputs were invaluable and deeply appreciated.

INTRODUCTION Continual increases in energy costs in the United States affect wastewater treatment plants (WWTPs) just as they do other facilities. Energy costs can account for 30 percent of the total op[1]eration and maintenance (O&M) costs of WWTPs (Carns 2005), and WWTPs account for approximately 3 percent of the electric load in the United States. Furthermore, as populations grow and environmental requirements become more stringent, demand for electricity at such plants is expected to grow by approximately 20 percent over the next 15 years (Carns 2005). Energy conservation is thus an issue of increas[1]ing importance to WWTPs. This fact sheet describes possible practices that can be imple[1]mented to conserve energy at a WWTP.

SUMMARY The process of electricity generation from fossil fuels such as coal, oil and natural gas requires water supplies for a number of essential power plant processes. The primary application of modern water treatment technology is to maintain the integrity and performance of the power plant. Critical plant applications have water purity or conditioning requirements that must be adhered to for safe, reliable and efficient power generation. Experience has shown that integration of water technology treatments with power plant design can be very important in reducing operational problems and component failures.