The guidebook reviews green technologies' evolving role in correctional institutions and identifies issues for consideration when acquiring and implementing green technologies that reduce costs and increase the efficiency of resource use. It also discusses the opportunities and challenges in selecting and implementing green technologies in correctional settings. The seven chapters of the guidebook provide information on various types of green technologies. The topics addressed are the integration of technology and people; lighting; heating, ventilation, and air conditioning systems; plug-in appliances (including pumps and motors); materials flow (including recycling and toxics); water; and energy (including transportation). These chapters cover most, although not all, of the green technologies being used in corrections facilities in 2011. Subsections on future trends feature possible additions and improvements in the field. Each chapter contains lists of specific technologies, including well-established and more traditional examples, as well as emerging technologies that have proven to be cost-effective in saving money and increasing the efficiency of resource use while protecting public safety and staff security. Each chapter also contains links, references, and contact information for correctional institutions that have experience with the technologies described. Methodologies used in preparing this guidebook included literature reviews of primary and secondary sources, site visits, focus groups, and interviews of corrections practitioners. Appendixes provide additional information on financing and present a case study of waterless urinals as an example of a green technology.