Bitcoin with Nuclear Fusion and Quantum Computers


What would happen to the Bitcoin mining process if Nuclear Fusion was able to be harnessed and used to it's full potential, essentially giving the world unlimited clean energy? Assuming Nuclear Fusion isn't monopolised and is eventually given for free or a very little cost via taxes to every human on Earth. The only expense used for mining would be the equipment cost, would this have an effect on the value of Bitcoin? Are there any real negatives or concerns this could cause to Bitcoin?

The same with Quantum computing, if we have unlimited energy and can make as many quantum computers as we'd like. Could we see a shift in how Bitcoin is mined and protected. And again, if any, what would be any genuine concerns that Bitcoiners could face in this scenario.

As someone who is 100% behind Bitcoin. I don't want to be blinded or ignore any genuine concerns that Bitcoin could face in the future. I'm sure these questions have been answered already, so if any source material is available I'll be more than happy to recieve them.