It is the super-yacht for the carbon-conscious billionaire. Instead of polluting the Caribbean and Mediterranean with clouds of diesel smoke, oligarchs and sheikhs are being offered the chance to sail zero-carbon, with everything from their on-board plasma televisions and champagne fridges to the main propellor being powered by the sun.

A 24-year-old British boat designer has drawn up plans for what is thought to be the world's first carbon-neutral super-yacht, and has received inquiries from wealthy potential clients after unveiling the designs at recent yacht shows in Monaco and Abu Dhabi.

Alistair Callender, from Chichester in West Sussex, is promoting the idea of "eco-luxury" with plans for Soliloquy, an electricity-powered craft covered in photovoltaic film that harnesses the power of the sun. Fixed sails will double as solar panels to produce enough energy to propel the 58-metre-long boat at a cruising speed of eight knots, and even the hull will be made of sustainable timber instead of the usual more energy-intensive aluminium.

According to Hein Velema, one of the most prominent yacht brokers based in Monaco, his richest clients are intrigued by the idea of that their next floating mansion could be zero-carbon.

"I was sceptical at first, but I have spoken to a few clients who are willing to spend a serious amount extra to go green," he said. "In the current climate we are unlikely to see as many yachts as large as the Eclipse, but people will want to be first in other ways, such as being the first with a green yacht."

Last June, the world's largest private yacht, the 163-metre Eclipse, owned by Roman Abramovich, was launched complete with a military-grade missile defence system and an escape submarine. Callender said he intends his £40m vessel to appeal to the super-rich who until the global economic crisis competed to own ever larger, and often more polluting, yachts.

The global craze peaked in 2008 when 260 yachts longer than 30 metres were launched. The royal families of the UAE and Oman have spent hundreds of millions of pounds on yachts that look more like cruise ships and burn thousands of litres of diesel an hour.

A conventional yacht of the same size as Soliloquy powered on the usual marine diesel can burn up to 2,000 litres an hour travelling at 35 knots, according to Yacht Carbon Offset, a company that provides carbon offsetting for clients including Sir Philip Green, the retail magnate. A two-hour journey at that speed creates 12 tonnes of carbon dioxide. Such a craft can use a further 1,000 litres a day just to power the air-conditioning and electrical systems.

"These giant gin palaces use a huge amount of fuel and produce so much pollution, I wanted to prove the point that eco-luxury no longer needs to be an oxymoron," Callender said. "Even if billionaires don't want to be green, they can save money. There are at least 100 families around the world worth £200m or more who have invested in green technologies and businesses or made hefty financial commitments to the environment." That list includes the likes of Sir Richard Branson and Google founders Larry Page and Sergey Brin.

Soliloquy will feature three fixed sails rising up to 17 metres. They have been designed with solar panels built in by Solar Sailor, which has built solar-powered ferries operating in Sydney and Hong Kong and is currently helping the US navy develop unmanned solar-powered boats. The sails will be able to power the boat in winds up to 40 knots.

The superstructure of the boat above the waterline will be clad in energy-gathering photovoltaic cells, giving it a sleek, black appearance. Together with the sails, the solar panels will fuel four cells that will work in conjunction with diesel engines beneath deck when there is not enough solar power. Callender predicts the engines will only need to be fired on rare occasions, because super-yachts are mostly used in sunny climes.

The interior is likely to feature recycled leather, natural fibre upholstery and wood only from sustainable forests.