New Fusion Reactor Could Result in Cheaper Power Than Coal

Fusion energy sounds too good to be true. There are zero greenhouse gas emissions, no long-lived radioactive waste and a nearly unlimited fuel supply. The downside is that the economics of fusion energy haven't exactly worked out; fusion power designs aren't cheap enough to outperform systems that use fossil fuels, such as coal and natural gas. Yet change may be on the horizon.

Scientists have now designed a concept for a fusion reactor that, when scaled up to the size of a large electrical power plant, would rival costs for a new coal-fired plant with similar electrical output.

"Right now, this design has the greatest potential of producing economical fusion power of any current concept," said Thomas Jarboe, one of the researchers, in a news release.

The design actually builds on existing technology. It creates a magnetic field within a closed space in order to hold plasma in place long enough for fusion to occur, allowing hot plasma to react and burn. The reactor itself would be largely self-sustaining, which means that it would continuously heat the plasma to maintain thermonuclear conditions. Heat from the reactor would heat up coolant that is then used to spin a turbine and generate electricity.

The new reactor creates a magnetic field with a design known as a spheromak, which means that it generates the majority of magnetic fields by driving electrical currents into the plasma itself. This reduces the amount of required materials and actually allows researchers to shrink the overall size of the reactor.

Perhaps the best part about this new design is cost. A fusion power plant producing 1 billion watts of power would cost $2.7 billion, while a coal plant of the same output would cost $2.8 billion. This, in particular, makes the fusion power plant actually feasible.

That said, the concept is about one-tenth the size and power output of a final product. It will take years before researchers can scale up the prototype, and they still need to tweak the reactor's ability to sustain plasma efficiently. That said, this is a huge step forward when it comes to sustainable energy.

The findings are published in the journal Fusion Engineering and Design.