The lesson plans were revised in 2004-2005 by a team of professional educators and renewable energy experts and now include teacher resource guides, reading passages for students, student worksheets, and many other helpful improvements in an easy-to-download format. Lesson plans are grouped into four age levels designed for elementary school (grades K through 3, and grades 4 and 5), middle school (grades 6, 7, and 8), and high school. However, they can be used in other grades as well, or by parents and home schoolers to teach their children about renewable energy. If you are a teacher, we can arrange to have multiple copies of the lesson plans mailed to you free of charge.