Ally Winning, European Editor, PSD
Renewable energy has come on leaps and bounds over the last two decades. From being promising technologies that generated dribs and drabs of electricity to becoming a major part of our power generation capabilities. Large scale solar and wind power facilities can be found all over the world. But, there is one problem that we haven’t been able to overcome so far – the intermittent nature of most renewable resources. Tidal power offers lots of potential for 24/7 generation, but that technology is still in its infancy and cannot come close to competing with the current crop of cheap solar and wind power applications. Reliable, large scale storage could also provide a method of evening out the peaks and troughs of renewable energy supply, but scientists are still trying to find a way to make that come to fruition.
In the meantime, we have to rely on fossil fuels or nuclear energy to provide the power that we need when renewable energy sources are not at maximum efficiency. All of these forms of generation have downsides, whether its ecological from coal and gas, or the expense of setting up a nuclear power plant. However, there is one form of power that does offer some hope. Nuclear fusion generates power in a similar way to how the sun burns fuel. Unlike fission which splits heavier atoms into smaller ones, fusion combines light elements to make heavier ones. In fact, if it does eventually realise its potential, it could make electricity almost free, as well as being environmentally friendly. Scientists have been developing nuclear fusion generation for decades without coming much closer to making it commercially available. Instead, a series of small steps have taken place that have overcome one hurdle at a time. However, the most recent of these breakthroughs was a giant leap in relative terms.
Researchers at the National Ignition Facility (NIF) have come closest to getting a similar amount of energy out the process than what was put in. They performed an experiment on 8th August which output 1.3 megajoules (MJ) of energy, only 30% below the 1.9 MJ energy that had initially been put in by the laser. This performance was eight times the previous high set by NIF earlier this year and over 25 times more than previous tests three years ago. As well as the high level of energy output, the researchers also believe that they have also achieved a state called ‘burning plasma’, which is essential to make the process self sustaining.
Although this is breakthrough is great progress, there is still a long way to go before fusion is a reality. The next stage for the NIF scientists is to figure out how to hold the fuel together for a longer period of time. This will achieve far higher fusion energies to be released as more fuel burns. After that, the same process will have to be repeated several times every second at a much larger scale to come close to being viable.