There is one thing that futurists consider as a real danger. Let’s say you get your new energy source from fission, fusion, ZPE, hydrinos...whatever. Look around : the human race is already trashing the planet with CxHx sources(85% of supply)at an accelerating rate. Give them 1000 times the energy(whole atomic bombs for EVERYONE)and the environment gets wasted 1000 times faster.
No, not with CO2/global warming, WASTE HEAT from countless electrical/electronic gizmos COOKS the biosphere. Instead of a cleaner, greener world you get, from completely undisciplined human children, a HOT stinking garbage dump with 150 deg F and rising ambient daytime temps.
Oh yes, a VAST new energy source will be greeted with JOY by everyone; and a free KW leads immediatly to the demand for a free MW, then GW(energy is POWER to the people, and the love of money is the root of all evil, yes?). Do the math for 7 billion completely undisciplined children, idiots, criminals....
So, a hobson’s choice : either suffer high CxHx prices and thus limited uses thereof(shiver a bit)or watch the world/biosphere MELT with too much free energy=waste heat being dumped into it.
Energy babblers of one kind or another : hydrogen economy = solar/windmill sources, wave machines/geothermal = pathetic amounts produced, nucs = rad waste, on and on...and nobody looks into the MIRROR and thinks : white man buildem BIG fire, standem way back; indian buildem little fire, sittem up close....or learn to live within a limited budget and survive, the europeans do.