The eclipse will be the first total solar eclipse visible from Europe since 2006. The path of totality will cross northern Spain, Portugal, Iceland, Greenland and northern Russia. London is expected to see around 90 per cent of the Sun obscured, while shoppers in Paris queued for more than two hours outside a specialist store on Rue de Rivoli.

In Spain, where several areas lie within the path of totality, many distribution points have already sold out. Pharmacies in central Madrid have been selling certified glasses for between €3 and €4 a pair, while prices in France range from €1.50 to €5.95.

In London, one shopkeeper was limiting customers to a single pair as stocks fell to around 100. In Brussels, optician Fouad Mehdaoui was taking orders by phone and adding customers to a waiting list after securing a last-minute restock.

The eclipse is also expected to cause a temporary drop in solar power generation across Europe. Grid operator association ENTSO-E estimates that output could fall by up to 9.7 gigawatts between 19:15 and 21:30 CET, with the largest reductions expected in Spain and Germany.

Solar power currently accounts for around 13 per cent of Europe’s electricity generation. Grid operators have prepared control rooms, arranged back-up generation and postponed planned maintenance to manage the temporary fall in output.

France’s grid operator RTE expects solar generation to drop by around 1.8 gigawatts, while German operators are preparing for a reduction of roughly 2 gigawatts. Despite the scale of the change, transmission system operators say they do not expect the eclipse to threaten the security of Europe’s electricity supply.