Despite the billions invested into renewable energy sources such as solar, wind and hydro power generation over the last couple of decades, none may prove the answer to the clean energy puzzle. Or at least, secure only a role as part of the supporting cast.
The star turn of the clean energy future will instead be, many believe, a far more efficient source of energy – nuclear fusion.
We’ve gotten much better at generating electrical power from the elements using technologies like giant wind turbines, solar panels and the movement of water, either naturally or manmade. But every single one of these renewable energy technologies takes up a lot of space to generate meaningful amounts of electricity for the grid.
They also rely on particular conditions, like sunny or windy weather, which means they can never be relied on all the time.
Encouraging investment in these technologies has been the right decision. They have been proven to work and already make a significant contribution to the energy mix in many parts of the world. In 2022, solar and wind generated a record fifth of the EU’s energy consumption.
The DNV Energy Outlook report estimates renewables could account for as much as 85% of global electricity generation by 2050.
Source: DNV Energy Outlook Report
The problem is, generating so much electricity from renewables means giving over huge areas of land and sea to solar, wind and hydro installation. As well as altering landscapes in a way many find aesthetically objectionable, large scale renewable energy installations also have an environmental impact.
They take up space that would otherwise provide a habitat for different species and can damage nature more directly – wind turbines have killed millions of birds, bats and other flying creatures.
But until there is a better solution, investment in renewables will continue. It’s the only way global emissions reduction targets will be met.
Nuclear fusion as a clean energy alternative to renewables is another step closer
There is, however, hope that other new clean energy technologies that don’t yet exist will step up and relieve the burden from renewables. Technologies that will be far more efficient both in the amount of space they require, their reliability and the amount of energy they produce.
Many scientists are convinced the leading contender among these clean energy alternatives to renewables is nuclear fusion. It is the opposite process to the nuclear fission traditional nuclear power plants use – atoms are fused together rather than pulled apart.
The benefit of that inverse nuclear process is that, unlike fission, fusion is a safe process with the reaction coming to a halt in seconds if not carefully maintained. That means there is not any risk of a nuclear meltdown. Fusion also doesn’t produce highly toxic, difficult-to-dispose-of nuclear waste as a problematic byproduct of the energy creation process.
Nuclear fusion also produces far more energy than fission does. That means relatively small quantities of fuel are theoretically required to produce almost unlimited amounts of electricity.
The problem with nuclear fusion is that it is very difficult to create the right conditions for it to happen. It is the same process that happens inside our sun where hydrogen atoms are squidged together under huge levels of pressure squidge together hydrogen atoms to make helium. That process releases the energy that sustains our sun – and by extension, all life on Earth.
Catalysing nuclear fusion here on Earth requires putting hydrogen atoms under the same kind of intense pressure as they would experience in the centre of the sun. It also requires intense heat and a confined space.
Creating those conditions is both highly technologically complex and requires a huge amount of energy. Until recently, more energy input was required to achieve a fusion reaction than those catalysed produced. That changed late last year when scientists at the Lawrence Livermore National Laboratory (LLNL) in the United States announced they had managed to produce more energy from a nuclear fusion reaction than they had used to catalyse it.
At the time, proving that achieving net positive energy release from controlled nuclear fusion was possible was called a “monumental” step towards humanity mastering an almost unlimited source of clean energy.
The latest step forward in the quest for scalable, commercially viable nuclear fusion took place on July 30, when the LLNL team repeated the trick of producing more energy than used. A tiny 5mm wide pellet of fuel was targeted by powerful lasers that created a hotspot the diameter of a hair that would have reached temperatures several times those of the centre of the sun.
Last December the team produced 2.5 megajoules of energy output from an input of 2.1 megajoules. The 0.4 megajoules surplus was enough to make several cups of tea – maybe that’s how the success was celebrated!
The latest crossing of the net positive energy threshold produced 3.15 megajoules from an input of 2.1 megajoules. This time the surplus would have been enough to power the average household iron for about an hour.
These successes are still caveated with the energy input only measured by that needed to create the laser beams. Setting up the whole system required the input of many times more energy than what was produced.
But the proof-of-concept the two experiments provide is seen by the scientific community as “momentous”. The US Department of Energy called the latest result “a major scientific breakthrough decades in the making that will pave the way for advancements in national defense and the future of clean power”.
What still needs to happen before nuclear fusion power plants can power the globe with reliable clean energy?
Scientists involved in the quest for commercially viable nuclear fusion technology, and observers of the process, warn that while the recent breakthroughs are hugely important steps, it will be a long time until we see commercial powerplants that use it.
Stating that nuclear fusion has been 30 years away for 30 years has become a sardonic joke. And despite recent progress, it wouldn’t be a surprise for it to take at least another 30 years before homes and industry around the globe are powered by nuclear fusion.
It will also probably require another technique entirely to the lasers used by the LLNL team. Many think that magnetic fusion, which sees powerful magnets hold the superheated gas required for fusion to occur in place because it would immediately incinerate any physical container, is a likely contender.
It would theoretically allow for larger fuel capsules to become the ‘little suns’ nuclear fusion occurs in.
However, we’ve seen how quickly technological progress can accelerate once initial steps are taken and obstacles overcome. Alongside the rise of AI, it wouldn’t be a surprise to see nuclear fusion research to start to take faster strides forward than has been the case until now.
If we hope to achieve climate change goals set for 2050, we’ll continue to rely on advances in more traditional renewable energy technologies. And increasingly large numbers of space-intensive installations.
But by the end of the century, the hillsides, fields, rivers, reservoirs and coastal areas given over to millions of wind turbines, solar panels and hydropower technologies could be freed up again. We’ll hopefully have a better solution by then – nuclear fusion.