Cold fusion has been around as a serious research endeavor for decades, but we don't hear much about it because it's primarily been funded by the US Navy. But they've demonstrated that it is possible to the point where their next step is to build either a 10Mw or 100Mw reactor. For some reason the funding keeps breaking down (it looks like Lockheed has been the latest organization to develop cold feet over it, no pun intended).

We seem to have developed a mindset that if the temperatures aren't at least 5000F then it can't possibly be real.