SINGAPORE: Britain's Prince William attended the annual Earthshot Prize ceremony on Tuesday, which awards 1 million pounds ($1.23 million) to each of five green innovators working on projects including a cleaner lithium-ion battery and ocean conservation.

"The light of optimism is burning bright in our Earthshot finalists," Prince William said at the ceremony in Singapore.

The five winners includes one from Hong Kong who is working on building cleaner, recyclable lithium-ion batteries that are used in electric cars, and another that tightens marine enforcement to end illegal fishing and support ocean conservation.

Representing six continents and chosen from over 1,300 nominees, the 15 finalists' projects ranged from a scheme to plant, grow and digitally track trees in Liberia to a less carbon-intensive method of treating industrial wastewater.

This year marks the first time that the finalists are attending the awards ceremony in person, Kensington Palace said.

William, who became heir to the British throne after Queen Elizabeth died in September last year, set up the prize in 2020. Its name is a nod to former U.S. President John F. Kennedy's ambitious "moonshot" project and goal for the 1969 moon landings.

During the four-day trip to Singapore, one of Asia's greenest cities, William will meet Singaporeans and "learn about how local organisations are working to protect and restore our planet – from tackling the illegal wildlife trade and protecting the rainforest to incubating and scaling cutting edge innovations," Kensington Palace said.

This is William's first trip to Singapore since 2012, when he visited with his wife Kate, the Princess of Wales.