There has been some progress in reducing global fossil-fuel use in power generation, from 87% in 2000 to 84.3 % in 2019. This reduction resulted from an increase in renewable sources (hydroelectric, wind and solar) from 7% to 11.4%.
However, nuclear power generation declined from 6% in 2000 to 4.3% in 2019 because of the closure of nuclear plants, which have not been replaced. France is unique in that 70% of its power continues to be generated from nuclear power plants.
Because of strong popular pressure, nuclear energy is not popular with energy planners, but this decline is regrettable, because it is carbon-free and thus fills an important need in a “green” global strategy. Electricity grids in modern economies must be flexible, reliable and able to meet demand variations smoothly. Wind and solar energy sources on their own do not satisfy this key grid requirement and more stable sources are needed to complement them.
Wind and solar energy are promoted as the green building blocks of the new world. But as industrial-scale electricity sources, both suffer from serious deficiencies because their output depends on uncontrollable weather conditions. This can cause near-catastrophic reductions in the grid electricity supply.
A recent example is noteworthy. The UK, with 20% of its power from wind, recently suffered a major electricity supply problem because of big wind-intensity reductions. The shortfall had to be made up with the increased use of natural gas, a fossil fuel, in established power plants.
Looking to the future, banning fossil-fuel plants leaves nuclear power generation as the only proven reliable technology for large-scale carbon-free electricity generation. Such plants can supply the power needed to maintain the required power levels as part of networks that complement as wind and solar sources fluctuations. We are talking of grids comprising renewables and nuclear power and whatever fossil-fuel power plants are chosen to remain.
Public memories remain vivid of a few big nuclear-power-plant disasters in recent decades. So the term “nuclear power” is unmentionable, while solar energy and wind are assumed to be the answer to global carbon-free electricity generation.
Usually forgotten in popular discussions is that the consistency of electricity generation is an essential requirement, and neither solar nor wind generators meet that requirement. Hence such sources require linkage to a power network that is capable to maintain consistent electric power to complement and balance changes from solar or wind sources.
Hydro-generated power can fill this role in some geographies but in the absence of nuclear power generation, fossil-fuel plants must provide such power. This is not consistent with a carbon-free global strategy.
Certainly, ideas for grid sustainability are not lacking. Interconnections of national and regional grids to provide an answer to fluctuating local power can be increased, but the issue here is the scale of such interconnections, their cost and their vulnerabilities. At the end, reliable standby power sources must be provided to sustain electricity grids.
Massive electricity storage systems are a possible answer, but face huge practical and cost hurdles. In fact, big Li-ion battery storage systems are used in a limited way, but considering the massive needs for national grids, the scale of needs dwarfs the expected availabilities of such batteries. This is especially true because of competing needs for batteries in electric vehicles. Furthermore, adding such batteries on a massive scale would add a great deal of cost to the electricity provided.
One proposed technology uses hydrogen gas storage combined with fuel cells. Such systems have been demonstrated on a small scale but face big technical and cost hurdles to scale for grid use. There is no evidence so far that such battery schemes on a large scale are both reliable and cost-effective.
An alternative technology to the commercial nuclear one has been in the research stage for decades: fusion energy generation that duplicates on Earth and in a controlled way the energy-producing process in stars.
This technology, long supported by government funds in the US and elsewhere, is promising in principle but far from being proved to be commercially feasible. But is is attracting new private funding (see “Money gushes into efforts to harness energy of stars,” New York Times, October 10, 2021). Progress could be accelerated, but in any case we are decades from practical systems given the enormous complexity and safety issues that would be involved in deploying them.
So for now the current nuclear power technology is what can be counted on. What stand in the way are safety concerns. While this technology has been successfully in use for decades, safety concerns remain, but these have been understood and addressed. We can expect that with continued investment such power plants can provide the grid balance essential for cost-effective and reliable networks. If we want a carbon-free world, this is one of the required programs.
Henry Kressel is a technologist, inventor and long-term Warburg Pincus private equity investor. Among his technological achievements is the pioneering of the modern semiconductor laser device that enables modern communications systems.