UAVs have similar requirements to the electric vehicle, although with very demanding power requirements and less taxing affordability requirements. As with renewable energy applications, greater proximity to human life correlates with more stringent safety needs, and high specific energy and charge speed remain key given the need to reduce weight to produce enough thrust required for lift and the need for quick re-charges to get back into flight . Examples of UAVs include military, recreational, security, package delivery, and even agricultural imaging .