To solve this problem we would have to rethink what we envision as a helicopter
While it may sound like fuel cells are pretty high tech stuff and you need a phd to understand them, in fact the reaction I described about is relatively simple.
Fun With A DIY Solar Motor. Here is a great diy clean energy project for the weekend! A motor powered by the sun directly. It does not use electricity but instead depends on the polymer…
There are commercially available tubes that work with the highest efficiency. They are known as solar evacuated tubes because they have a small vacuum drawn into them.
The examples cost savings are based on the cost of energy in France, so the kwatt savings may be more interesting to you for comparison.
James Cameron is an environmentalist as well as a movie director. Here is the a video about The Sunflower, his open source solar energy system.