Which of the following is NOT an example of on-site generated renewable energy?

Renewable Energy Credits (RECs) represent a market-based instrument that certifies the bearer has contributed to the generation of renewable energy. While RECs can be purchased to offset carbon footprints or to indicate support for renewable energy initiatives, they do not involve the physical generation of energy on-site.

In contrast, solar energy, biofuel-based electrical systems, and wind energy involve the direct generation of renewable energy at the actual site of the project. For instance, solar panels installed on a building generate electricity on-site, and wind turbines installed in proximity to a facility produce energy right there. Similarly, biofuels can be produced and converted into energy on-site, making all those options true examples of on-site generated renewable energy.

Thus, while RECs play an important role in promoting renewable energy usage and sustainability, they do not constitute a form of energy generated at a specific location, marking them as the correct choice for what is not considered on-site generated renewable energy.