One of the most ambitious science projects ever attempted is underway in France which if successful, could pave the way to unlimited clean energy - forever.
The International Thermonuclear Experimental Reactor (ITER) is, in simple terms, an attempt to build a star on Earth.
The reactor aims to recreate the process which powers our sun, where elements are fused under extreme temperatures, releasing massive amounts of energy in the process.
The ITER team, who recently completed the installation of the first of several major components, aim for the reactor to be fully operational by 2025.
However the engineering challenges they face are immense, ITER must achieve a core temperature of 150 million degrees centigrade in order to function. For comparison, our sun has a core temperature of 15 million.
If ITER is successful, the reaction could be sustained indefinitely as some of its principal fuel sources can be distilled from water.
While ITER is a nuclear reactor, it uses a completely different process to the standard nuclear fission reactors currently in use.
"In a fission reactor you take uranium and you break it into smaller parts and we do exactly the opposite for the fusion," Auckland University physics professor David Krofcheck told Newshub Nation.
But for those concerned about the environmental impact of the project, Professor Krocheck says fusion could be even more green than some renewables.
"Fission is a fundamentally different physics process than is fusion and the fusion process is inherently much cleaner.
"I think you could make a strong case that this is more environmentally friendly than hydropower. It's just that people are more familiar with water than they are with nuclear fusion."
ITER would also not produce the same types of long-lived hazardous waste as traditional reactors and cannot create the kind of disastrous chain-reaction seen in Chernobyl.
Despite the complexity of ITER, it also uses some surprisingly traditional methods to generate electricity. According to Professor Krofcheck, even the most advanced reactor is essentially an expensive kettle.
"All these high energy techniques are just a very fancy way of boiling water. To transfer heat from whatever particles are coming out of your nuclear reactions, you still need to convert that into electricity."
"You convert those particles motion into heat energy to heat water which then causes steam to get created, which turns the turbine, which generates electricity. So water is the universal solution to all the problems of generating electricity."
ITER is a collaboration between multiple countries, with the European Union responsible for the largest portion of construction costs (45.6 percent); the remainder is shared equally by China, India, Japan, Korea, Russia and the US (9.1 percent each).
More information on ITER and its construction can be found here.