Week energy highlights

From 10 to 16 of December 2022

Photo by Federico Beccari on Unsplash

Fusion Breakthough! Or not?

The National Ignition Facility announces a breakthrough in fusion energy. It was widely covered in the media has the event that finally delivers fusion energy.

But is it true, or is it hype? Both.

The National Ignition Facility used 2.1 MJ of laser light, resulting in 2.5 MJ of fusion energy. That much is true, and it’s an great accomplishment.

It’s the first time someone achieves a net gain comparing the input energy with output.

However, the lasers have 0.5% efficiency. Which means:

To get 2.1 MJ of laser light, they used 400 MJ of electricity from the grid. If you account for that, you spent 400MJ of electricity to get 2.5 MJ of energy release, which is no net gain. It’s a substantial net loss.

Further still, 2.5 MJ of energy released is far from being 2.5 MJ of electricity.

The pathway generally posited to harness fusion energy and convert it to electricity is similar to fission. Use heat to drive turbines.

This approach will result in energy losses in conversion. Assuming all energy fusion release would get converted to heat, the best turbines have efficiencies just shy of 50%.

So this would mean: from 400 MJ of electricity you get 1.25 MJ of electricity.

And the lasers take hours to cool down and prepare for another shot. So, it is an great achievement on the physics level, but it’s not the great engineering achievement that unlocks fusion energy to the masses.

And it’s good to remember that fusion energy is not the main purpose of the National Ignition Facility: it’s defense, particularly nuclear weapons research.

The world’s largest isolated grid reaches 84% of renewable share

The world’s largest isolated grid reaches 84% of renewable share. In the 10:30 to 11:00 period of Monday, December 12 the Western Australia’s South-West Interconnected System reached this record.

Rooftop alone reached a 59% share of generation, with wind providing another 19% toped by a 5.5% share from large utility solar. (See figure 1).

Figure 1: Record renewable share in Western Australia (source)

Distributed solar (rooftop, small owners) even reached a 61% share between 12:00 and 12:30 of the same day (see figure 2).

Figure 2: Example of high PV rooftop generation share (source)

Why is this important? Because there was a long standing debate from critics that a grid could not function with a large renewable share. Since Western Australia grid is isolated, it can not rely of energy imports from other grids.

In this case the grid kept on working because of renewables; there were suply problems with both coal and natural gas.