Fusion ‘101’ – Why is it important for climate change and weather balloons?

Some things in science are just cool. Others are cool and can be life changing. This week, the US Department of Energy announced that one of its labs, the Lawrence Livermore National Laboratory (LLNL), had performed what is called fusion ignition. Let’s see what this means and why it matters for climate change.

The Ministry of Energy Press release said: “On December 5, a team from LLNL’s National Ignition Facility (NIF) conducted the first controlled fusion experiment in history to achieve this milestone, also known as the scientific energy break-even point, which which means it produced more energy from the fusion than the laser energy used to conduct it.” Fusion is the same process by which the Sun produces energy. For decades, scientists have sought to replicate the mechanism in labs, but it has been elusive. Dr. Arati Prabhakar, the president’s chief science and technology adviser and director of the White House Office of Science and Technology Policy, said: “We’ve had a theoretical understanding of fusion for more than a century, but the journey from knowledge to action can be long and arduous. Today’s step shows what we can do with persistence.

So why is it important for climate change? Fusion occurs when two lighter nuclei (in this case hydrogen) combine to produce a single heavier nucleus (like helium). During this process, a significant amount of clean energy is released. The Department of Energy’s press release went on to say, “This historic achievement, the first of its kind, will provide unprecedented capability to support NNSA’s inventory management program and will provide invaluable insight into the prospects for clean fusion energy, which would be a game-changer for efforts to achieve President Biden’s goal of a net-zero carbon economy.

This announcement is a game-changer for the science, technology and engineering communities. However, it is important to calibrate expectations. We are still likely years, if not decades, away from mimicking the power of the Sun at scales large enough to meet today’s energy needs. This experiment produced enough net gained energy to boiling a few gallons of water, but that’s not the exciting point. The fact is that more energy was produced as output than delivered as input. Keep in mind that the first plane was not a Boeing Dreamliner and the first cell phones required a little practice to lift.

However, it is very attractive and hopeful to envision an energy economy free of emissions, air pollution or radioactive waste. The fuel supply for fusion is hydrogen. Hydrogen is very abundant. As you read this, you might be wondering how fusion differs from fission in nuclear power plants. The International Atomic Energy Agency website says, “Fission splits a heavy element (with a high atomic mass number) into fragments; while fusion unites two light elements (with a low atomic mass number), forming a heavier element. Both processes release energy, but fusion does not produce radioactive waste. It produces inert helium (which can be used in weather balloons by the way). Fusion also does not produce the chain reactions characteristic of nuclear accidents, nor is it really viable for the production of weapons.

Maybe now you see why scientists are giddy.