The Pak Banker

Nuclear energy plants

- Henry Kressel

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 carbonfree 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 nuclearpow­er-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.

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