It could usher an era of limitless clean, safe and affordable energy to meet the world's demand.
Now, the 'holy grail' of power production – nuclear fusion, which makes the sun and the stars shine – has come a step closer.
Scientists have switched on JT-60SA, a £500 million fusion device measuring around 40 feet in diameter, located in Naka north of Tokyo, Japan.
JT-60SA contains swirling plasma heated up 200 million degrees Celsius (360 million degrees Fahrenheit).