The main advantage of HVDC, and the reason it rules for undersea/underground cables is that it requires less insulation. HVAC must be insulated to peak line voltage equal to 1.42 times the rated line voltage spec.
For overground lines this is not a problem---just space the lines out a little more. For a compact cable however this leads to huge cost savings.
Drones are, in essence, flying autonomous vehicles. Pros and cons surrounding drones today might well foreshadow the debate over the development of self-driving cars. In the context of a strongly regulated aviation industry, "self-flying" drones pose a fresh challenge. How safe is it to fly drones in different environments? Should drones be required for visual line of sight – as are piloted airplanes? Join EE Times' Junko Yoshida as she moderates a panel of drone experts.