[Becky Stern] likes to harness the power of the Sun. Most of us will immediately think of solar cells and other exotic solar energy techniques. But [Becky] shows how to make a hot air balloon using nothing but tape and garbage bags.
The idea is quite simple. You form a large envelope from black trash bags and fill it with air. Becky does that by just running with it, tying it off, and topping off with a little manual blowing. Once the sun heats the black bag, it floats.
We were hoping she’d show us if there was any margin for payload, but she didn’t. However, electronics are getting smaller and lighter all the time. Sure, batteries weigh a lot, but maybe there would be an opportunity to mount some solar-powered device on the balloon to further harness the sun’s energy.
If you want to have a go at that, [Becky] has a free solar class that covers using the sun to engrave wood and using solar panels to charge a battery or power an Arduino.