We also have a good few estuaries that could create electricity relatively easily - using known and proven technology, which fusion certainly isn't.

Bottom line is these figures are either incompetent or disingenuous.

I'm old enough to remember fusion being touted as the Next Big Thing for literally all of my life. Commercial containment fusion seems no closer now than it did fifty years ago.

There are alternatives, but they're highly speculative. Dropping YC cash on them makes sense as a long shot, but the science doesn't suggest it's wise to expect them to make good.