The dream of almost limitless clean energy from nuclear fusion is close to being realized. After 6 decades of research and testing fusion finally appears to be on the cusp of delivering on its promise to revolutionize energy production. Sometimes called “star in a jar” because the technology mimics the energy conversion processes like those in our sun.
UK-based Tokamak Energy has announced that it has a working fusion reactor called ST40. The cost-effective reactor has achieved a critical step known as ‘first plasma’ that heats plasma. They plan to reach the fusion threshold of 100 million degrees Celsius (180 million degrees Fahrenheit). They hope to be able to generate plasma at temperatures of 15 million degrees Celsius (27 million degrees Fahrenheit). The goal is to start a chain reaction that will fuse hydrogen atoms into helium.
The ST40, also known as the Tokamak machine uses magnets, salt, and water to produce carbon-free energy. Because atoms are being fused rather than split (as is the case for existing nuclear fission power plants) the only waste product is helium. The company hopes to have utility-scale commercially deployable technology by 2030. This most recent fusion achievement comes on the heels of other strides that have been made in the US, Germany, and elsewhere.In 2016 scientists from MIT broke the record for plasma pressure. Using powerful new magnet technology engineers at MIT’ have developed a mini modular fusion ARC reactor that generates the same amount of power as its larger predecessors. The small size of this reactor contributes to its cost-effectiveness.
As with all fusion reactors, it is all about magnet technology (magnetic field technology). The heat is so intense that magnets are required to keep the super-hot plasma from touching the walls effectively suspending the plasma in space. MIT specifically uses barium copper oxide (REBCO) superconducting coils. MIT hopes to have utility-scale energy production by 2025. At the end of 2015, a German fusion reactor called the Wendelstein 7-X (W 7-X) “stellerator” successfully controlled plasma. In 2016 the stellerator achieved the more challenging goal of working with hydrogen plasma.
The stellerator is an international effort that is currently operated by Max Planck Institute for Plasma Physics in Germany. Tests were conducted in collaboration with scientists from the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL). These tests confirmed that it worked. What makes the stellerator superior to the Tokamak reactor is that it controls plasma without the need for any electrical current. This makes the stellerator more stable because it can keep going even if the internal current is interrupted.
In 2019, the reactor will begin to use deuterium instead of hydrogen to produce actual fusion reactions. This research is more of a proof of concept than an attempt to build a utility-scale energy.
France’s ITER tokamak reactor has also been able to trap plasma long enough for fusion to occur. In December 2016, South Korean researchers became the first to sustain ‘high performance’ plasma of up to 300 million degrees Celsius (540 million degrees Fahrenheit). However, this lasted for only 70 seconds.
