LONDON — Britain's Prince William is trying to help save the planet by helping inventors save the planet. On Sunday, he is hosting a kind of Oscars awards and broadcast — for an audience into green hydrogen energy, coral reef restoration and using insects in compost toilets.

The heir of the heir to the British throne is the founder of the Earthshot Prize, which will give 1 million pounds ($1.4 million) each to innovators whose ideas could help mitigate climate change and address some of Earth’s most pressing environmental problems.

Ahead of the inaugural awards ceremony, the Duke of Cambridge has been speaking out on climate, with remarks that, by royal standards, have been a wee bit sharp.

He told the BBC there should be more focus on fixing this planet than finding another one to live on. The comments were widely viewed as a swipe at billionaires Jeff Bezos, Elon Musk and Richard Branson, all engaged in the space tourism race — though Bezos has also pledged $1 billion to land and sea conservation and Musk’s money comes largely from his electric car business. (Bezos owns The Washington Post.)

Prince William’s answer to the climate crisis has been to use his profile — and money from “founding partners” — to launch the Earthshot, self-billed as the “most prestigious global environment prize in history.”

Every year until 2030, five winners will be selected.

More than 750 candidates were put forward by a panel of more than 200 experts. Fifteen finalists were shortlisted. They are vying for the prize money, and also grant money and venture capital support to help scale up.

Among the boldfaced names judging the final round: nonagenarian British TV naturalist David Attenborough, Jordan’s Queen Rania, actress Cate Blanchett, singer Shakira and basketball giant Yao Ming.

Some of the winners will join Prince William when he attends COP26, the upcoming global climate talks in Glasgow, Scotland.

Here are a handful of the eye-catching projects:

Solar-powered ironing

In parts of India, roaming “ironing wallahs” use charcoal-powered irons to press wrinkles out of clothes. There are an estimated 10 million ironing carts that each burn — on average — about 11 pounds of charcoal per day.

Vinisha Umashankar, a 14-year-old student from India’s southern Tamil Nadu state, has invented a solar-powered ironing cart to help reduce pollution in cities, including her own. The cart is attached to a bicycle, meaning it’s mobile, and it has solar panels on its roof. It takes about five hours in bright sunshine to fully charge, and vendors can use the iron for six hours a day.

She told The Washington Post that the ironing-cart concept could be applied to other street vendors, too. “Soon, there may be solar veg-carts or ice-cream carts, you never know,” she said. She added that teenagers “can definitely be good innovators. We are at an age where we have so much energy and drive. . . . Our youth definitely has the power to do good in this world.”

Living sea walls

As the oceans rise in the warming world, humans will build sea walls to protect their cities. Already, the built coastal infrastructure — walls, pilings, pontoons, marinas — is greater than the area of all the planet’s mangrove and sea grass forests.

Traditional sea walls are mostly barren, as they lack shelter to encourage the biodiversity of a natural environment. But Living Seawalls, a project started by the Sydney Institute of Marine Science, deploys ocean scientists and industrial designers to create “habitat panels,” plates about the size of a large pizza pie that can be screwed onto the sea walls and mimic natural formations, such as rock pools and mangrove roots.

Upon these panels, life does grow. The panels are built of “reinforced concrete from 3-D printed molds to form complex habitat geometries,” the developers say. They are available in 10 designs — with names like “kelp holdfast” and “sponge fingers.”

The Earthshot judges report early positive results: “Living Seawalls have 36 percent more marine species than flat sea walls after only two years. Eighty-five species now thrive among the panels.”

A pollution-tracking app

When Ma Jun worked as an investigative journalist for the South China Morning Post, he reported on the impact of air and water pollution created by the booming economy. As an environmental activist, he realized that to fight pollution, you have to measure it and share that information, leading him to found Blue Map.

Blue Map is China’s first public environmental database, accessible via smartphone, offering citizens detailed information on emissions and effluents, from 40,000 factories, bolstered by 160,000 air- and water-quality data points, collected each day.

Users can employ this “big data” to “name and shame” offending businesses and municipalities — and produce results.

“With 10 million downloads, Blue Map’s network of concerned citizens becomes part of the multi-stakeholder initiative that is changing China’s cities,” the Earthshot judges say. “It also teaches the world a lesson — that clever innovation, combined with public participation, is a recipe for progress.”

Paying locals to protect forests

Despite the crucial role that forests play in protecting wildlife and buffering climate change, global tree loss is accelerating. Last year, nearly 7 percent more trees were lost than the year before.

The government of Costa Rica, one of the finalists, thinks it has a model that others could use to reverse deforestation. The government pays its farmers not to cut trees.

In the 1970s and ’80s, Costa Rica had some of the worst deforestation rates in the world, as locals toppled trees to make way for crops and cattle farming.

In 1997, the government took drastic action by introducing a “payments for environmental services” program, which rewards landowners — via direct bank payments — for protecting the forest, reforestation, sustainable forest management and agroforestry. The financial incentives have proved crucial in helping Costa Rica become the first tropical country to not only stop but to reverse deforestation.

Electricity to go

Olugbenga Olubanjo grew up poor in Nigeria, one of 70 million people in the African nation without reliable electricity. He founded the start-up Reeddi, which provides portable rechargeable battery units to consumers from a vending machine powered by solar panels.

Reeddi rents its solar-powered energy capsule, a lithium battery, for $0.50 a day, by cash, mobile phone app or debit card. You take the unit home and are given reward points when you return it.

The United Nations reports that there are 600 million people living without access to electricity in Africa. The Earthshot judges think this could be a clean, green, sensible way to bridge the gap.

The company says it provides units to over 600 households. If scaled up, with the help of prize money, that number could grow to 12,000 by 2022. Reeddi says its customers use their capsules to power laptops, TVs, fans, lights, radios, phones and, for barbers and beauty salons, hair clippers.

Poop-eating fly larvae

Urban sanitation is a growing problem in cities around the world, especially in sprawling city slums that don’t have sewer systems.

A Nairobi-based company called Sanergy is helping to clean up cities by converting human waste into products that can be used by farmers.

Sanergy builds waterless toilets that don’t need to be connected to a sewer system. Underneath the toilets are blue barrels that, when filled, are removed and taken to a recycling factory. There, it’s time for creepy crawlies to get to work. The human waste is consumed by black soldier fly larvae, which in turn transform the feces into organic fertilizer and other agricultural products that can be used by local farmers.