The book covers the various components of the undergraduate course on Non-Conventional Energy Resources (Alternative Energy Resources, Renewable Energy Resources) quite well. The first edition came out in 2006 and was well received by the academic community. Its potential seems to be much more as the course is gaining importance across colleges. As is with the first edition, the second edition was necessary in order to further hone the contents as per the syllabus and competition requirements. Also since the subject is evolving with time the book requires regular updation. The contents of the first edition have been thoroughly reviewed and revised and updated. Two new chapters, several new topics and sections and subsections have been added. This edition is also pedagogically enhanced due to the addition of solved university questions, objective questions and model question papers. All in all it promises to be one of the best books on the subject.