While renewable energy sources are becoming more popular, they aren’t 100% environmentally friendly. The production of solar panels and wind turbines currently requires the use of non-renewable energy sources. Mining and development of the materials used in lithium batteries and in many solar panels also have raised environmental – and even human rights – concerns. Also, lithium batteries and solar panels need to be replaced without an environmentally sound disposal system. Wind turbines have also historically had no ability to be recycled and typically end up taking up significant landfill space.