King Charles has hailed the “wonderful” work of a British company developing the next generation of solar panels, though he light-heartedly referred to the “disaster” of his plaque unveiling.

During his tour of Oxford PV (Photovoltaics) headquarters, the King saw panels significantly more efficient than conventional products, which he described as “so vitally needed”.

The head of state has championed sustainability and climate action for decades, regularly speaking about the planet’s threats and adopting practical measures, such as running his Aston Martin on eco-fuel.

He told a group of staff “I hope you can speed up the transition a bit” – an apparent reference to the aim of moving away from fossil fuels to renewable energy.

The King added: “I think you’re remarkable, how you’ve managed to keep it all going, but it does take time to get to the point where you can actually commercialise all these things.

“But we need it all badly, all your products, fantastic – applicable on one or two roofs.”

There was a lighter moment when Charles pulled a sheet to unveil a plaque to mark his visit, quipping “disaster” after it tumbled to the ground from an easel.

He was shown the research and development lab of Oxford PV, founded in 2010 as a spin-out from nearby Oxford University, which has become a world leader in using light-sensitive perovskite to develop solar panels that are over 20% more efficient than conventional panels.

He looked at an electron microscope image of the surface of perovskite, a material layered on to silicon solar panels to increases their efficiency at creating electricity as it absorbs different parts of the light spectrum.

The King was delayed by around 45 minutes when bad weather forced him to switch from a helicopter to a car for his journey to Oxford, believed to be from London, and he joked a number of times about the delay after apologising for being late.

When Charles was shown images of commercial applications of the advanced solar panels, not yet available to the public, he appeared impressed with the potential use in car manufacturing, aeronautics and satellites.

David Ward, chief executive of Oxford PV, said after the visit that the firm was shipping “pilot volumes” of products to early customers, adding: “There’s been a decade of work, getting it from a brilliant piece of science into a real module that you see here, that we could give to a customer and they put on a roof.

“I don’t think one energy source will dominate all others, but solar right now is the cheapest form of energy generation and deals with security and energy transition.”