The Prince of Wales congratulated the finalists of his Earthshot Prize as he met them for the first time at a retreat in the grounds of Windsor Great Park.

William joined the 2022 finalists at Cumberland Lodge on Thursday.

He met each finalist in turn, asking them what he could do to help them.

He spoke to Min Wang, whose company, Desert Agricultural Transformation, turns desert sand into agricultural land.

She invited William to visit one of her project’s sites in China.

He said: “If I am passing by I will be visiting all of your projects. I have made a note to my team.”

He added: “So by year 10 I will still be visiting Earthshot projects.”

He also spoke to Kaushik Kappagantulu, whose company Kheyti’s mission is to increase climate resilience for smallholding farmers in India

William praised the initiative, adding: “Kenya and India are two countries that are really stepping up to the mark.”

He then met Charlot Magayi, whose company Mukuru makes clean and reliable cook stoves for low-income households in western Kenya.

Ms Magayi grew up in Mukuru, the third largest slum in Kenya. Her business focuses on providing families with clean stoves that are less likely to expose them to harmful air pollution in their own homes.

William gave her a particularly warm greeting.

“Congratulations,” he said. “The last time I saw you you were surrounded by children. Your story is unbelievable.”

Speaking to the PA news agency afterwards, Ms Magayi said: “I started my business in 2017 because my daughter got burned by a traditional stove.

“I grew up in a slum in Kenya, and that is the reason why my business is called Mukuru.

“So I wanted to create a stove for my community, and then we did, and it just blew up.”

William went into private group sessions with the finalists, where they spoke to him about their hopes and ambitions for the year ahead.

The finalists are on the second last day of a week-long retreat at the lodge, where they have met, learned from and collaborated with each other, and heard from leaders and thinkers who have advised them on how to scale up the projects they are working on.

William is the founder and president of the prize, which honours environmental pioneers.

The finalists attended talks by Christiana Figueres, former UN climate chief and Earthshot Prize board chairwoman, and Hindou Oumarou Ibrahim, environmental activist, geographer and Earthshot Prize council member.

They also attended a forum hosted by Deloitte in London, where they were connected with advisers, market access partners, and potential funders.