Which of the following is judged on-site at Tech Day?

The reason the Alternative Energy Design - Wind Turbine is judged on-site at Tech Day is that this event typically involves hands-on demonstrations and presentations of projects, allowing judges to assess not only the written design plan but also the actual functionality and design implementation of the entries. This type of project often includes the practical application of engineering concepts and teamwork, making it essential for the evaluators to observe the project in action.

Other choices, like Membership Recruitment Challenge materials, may have other evaluation processes that do not necessitate on-site judging, focusing instead on presentations or reports submitted prior to the event. The pin design, while creative, is usually judged based on submitted visuals rather than in-person demonstrations.