Nuclear reactors release a staggering amount of energy. In practical terms, one kilogram of uranium can release as much energy as 1,500 tonnes of coal. Existing nuclear plants are also cheap to run and they are CO2-free with the added benefits of no air pollutants.

However, the real issue with nuclear is that new-build costs have gone up as the years have gone by, as have the costs of decommissioning existing plants. In addition, public support has waned for nuclear following a series of accidents — the most recent of which being Fukushima — as well as the inability of the nuclear industry to build new plants on time or on budget.

Finally, it is really difficult to receive planning permission even for pilot plants for next-generation nuclear technologies.

This all begs the question: what role will nuclear have going forward?

The nuclear industry began in the 1950s and by the end of 2020 there were 443 reactors in operation across the world, with an installed capacity of 393GW. Some 10.3% of all electricity produced across the globe came from nuclear power, with France generating nearly three-quarters of all its electricity from nuclear. However, the facts over the last decade speak for themselves: nuclear is in decline.

Back in 2010, there were only 16 new reactor construction starts, which was well below the peak of 1976, when construction started on 43.

Last year, there were only five.

There have also been many plants that have closed since the Fukushima accident in Japan in 2011 and, despite strong growth of nuclear in China, there are fewer plants running today than before Fukushima.

Increasing needs for safety around nuclear plants have pushed up costs. A case in point is the UK, where the new 3.2GW Hinkley Point power plant is now expected to cost up to £23bn (in 2015 prices) ($32.5bn), up from the original 2012 estimate of £12bn. When it is finally finished in 2026 it will have taken over ten years to build and the end customer in the UK will be paying a price for that energy that is three times the wholesale market price.

The other element against nuclear is lower-cost alternatives in the form of wind and solar. Over the past decade, there have been some 50GW of nuclear capacity added to the grid across the world. Over the same period, more than 1,300GW of wind and solar capacity have been installed.

Why is this happening? It is easier for governments to hit carbon targets with renewables, which are seen much more positively by voters, as well as being much quicker to install and lower cost to build and operate. In the US, some nuclear plants are being closed because they are not profitable; their operating costs are just too high and they are not competitive compared to natural gas and renewables plants.

Looking forward, the logical approach from a climate change perspective would be to upgrade existing nuclear plants and run them as long as technically possibly. This is lower-cost than many other alternatives and pushes out the massively expensive decommissioning costs, which are heavily subsidised by governments across the world. But even then, there is public resistance.

The one light at the end of the tunnel may be so-called Small Modular Reactors, which are basically scaled down versions of normal reactors and can be mass-produced, so the theory goes, and are thus cheaper to produce. The new designs are safer to use with lower amounts of radioactive waste. However, there are multiple designs out there, with none at scale, which makes it debatable if — rather than when — this technology will come to market.

What this means is that the future of nuclear is not so rosy. We will see small incremental additions to the global nuclear fleet but we will see no nuclear renaissance.

Does this mean we should give up on nuclear? Without a doubt, no. If we are able to crack nuclear fusion, the energy source used by the Sun, then we may have safe, plentiful and carbon-free electricity. To achieve that goal, we need to keep investing and doing research and development around nuclear, as it could be a silver bullet for climate change.