Free energy wont happen as long as people can make money on electricity. Also do you not see the catch 22 heere? In order to make Bitcoins you need electricity (yeah there are solar panels but how many use it?).
Can you name some of the technical innovations that BTC has made, if we look away from decentralizing part?
I understand that free energy won't be available to the masses if money can't be made with it. But I think that miners would have an interest in tracking down some devices and this would put market pressure on such devices being produced afterwards.
No new technical advances have probably occurred as a result of Bitcoin. Chip technology deployed is likely nothing new, nor are distributed computing concepts. The ways cryptography is used are new, but encryption algorithms themselves are probably not new. All of this is probably a good thing. It shows the empahsis that is being put on solving real-world societal problems. Bitcoin is not some university pet project by a longshot.