On Monday, December 7, 2015 at 12:04:51 PM UTC-5, Dan Marotta wrote:

I also agree that newer battery technology is needed to make this
anything more than a high-priced toy, but then that's what our
gliders are, aren't they?

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Dan, 5J

Did you see where the site mentioned they were looking at/working on a "hybrid"? Until battery energy density improves (a lot) they will add in a small generator to extend flight time.