A number of companies have been able to make these low-energy nuclear reactions work reliably, write Brian Josephson, David J Nagel, Alan Smith, Dr Jean-Paul Biberian and Yasuhiro Iwamura

Luca Garzotti observes (Letters, 22 January) that serious challenges face the production of energy from processes based on thermonuclear fusion, but failed to mention a crucially important alternative, low-energy nuclear reactions (LENR), commonly known as cold fusion.

Readers of the Guardian’s 2012 obituary of Martin Fleischmann will know that the situation regarding cold fusion is more complicated than that commonly assumed: that the claims of Fleischmann and Stanley Pons for the process were discredited. The reality is that subsequent research showed that it was the critics who were wrong, something not widely known because editors of the main journals, under the impression that the claims were false, blocked the publication of papers suggesting otherwise.