Activities offer a variety of exercises for the students to reinforce their knowledge. They do this in a variety of ways:
Standard Exercises: These are for the purpose of reinforcing knowledge and guide the students through doing things much as they are done in the lesson.
Data Inquiry: These are designed to nurture critical thinking. They can be a lot of fun as they create the opportunity for students to use the data to solve a problem. Sort of a CSI SLL. For example If only 14% of the sunlight's energy is converted into electricity, where does the rest go. One clue is that the module is hotter than the surrounding air, etc.
Data Projects: A project lesson is much like engineering in that the students take the data and design something. A simple example is to look at what percentage of their school's electricity could be produced with solar energy. This type of project requires some proactive effort by the students such as getting their hands on the school's electricity bills, investigating their solar array's size and output, finding the school's sized etc.