Refrigeration hasn’t changed in more than 100 years. Consumers have learnt blithely to accept energy-guzzling fridges that periodically need defrosting, or develop mysterious warm pockets. Existing systems also require a consistent power supply, which is a huge challenge for vaccine storage in the developing world.

Now, one British inventor has developed a new cooling technology, as simple and cheap to make as a bottle of water, that is set to revolutionise the refrigeration industry.

Ian Tansley has created a system that remains cold for up to 12 days without power. It maintains a consistent temperature throughout the fridge, eliminating the hot and cold fluctuations. The impact of such technology is significant. Not only can vaccines be safely transported to off-grid rural areas in developing nations where diseases such as polio still claim hundreds of lives each year, the massive energy savings will benefit both people and planet.

Tansley’s Snowdonia-based firm, Sure Chill, has spent almost a decade developing the technology. Its vaccine fridges are now in use in 40 countries around the world. In the first three months of this year, the United Nations’ children’s organisation, Unicef, is using 200 of its fridges to transport drugs to the Philippines as part of the relief effort.

Tansley came up with the idea for the ground-breaking invention while walking through the Gwynedd countryside in North Wales. “I was inspired by a frozen lake,” he says. “I thought, 'If hot water rises, why is the top of the lake frozen and not the bottom?’ That’s what gave me the idea. It’s just so simple and works with the density of water.”

Tansley is a serial inventor who has worked in the field of sustainable energy for 25 years. His first attempts at energy-efficient refrigeration involved solar panels, but it was only when he met angel investor Peter Saunders that he began looking at completely new power sources.

The pair met in 2005, a year after entrepreneur Saunders had sold Halo Foods. “Ian is an expert in alternative technologies and green energy,” he says. “I decided to build a business around him.”

Saunders invested £2.5m for 80pc of the company, and set Tansley the task of developing a new refrigeration system.

“All the vaccine fridges on the market require a rechargeable battery,” explains Saunders. “The problem is that once the battery fails, the expensive piece of kit goes to waste. The World Health Organisation was looking for a solution.

“After Ian had his brainwave, he locked himself in a room for a week,” he continues. “He had built this crazy, Heath Robinson arrangement, but the thing worked the first time we tested it.”

The Sure Chill entrepreneurs have global ambitions for their firm and their technology now has patent coverage in 89 countries.

The Sure Chill system appears to solve all the problems inherent in conventional refrigeration.

“We have achieved the evenness of temperature distribution,” says Tansley.

“While batteries wear out and don’t like high temperatures, this technology is robust and only needs short bursts of power to keep going indefinitely, even in tropical countries. And our technology costs as little as a bottle of water to build.”

Nevertheless, bringing the technology to market was a challenge. “People think that if a technology sounds too good to be true, that it is,” admits Tansley. “It was so difficult to get people who had worked in the refrigeration business for a long time to accept that this works.”

A turning point came when Sure Chill received endorsements from the World Health Organisation, the Clinton Health Initiative and renowned climate scientist Sir John Houghton. “We managed to get one of our fridges in front of Bill Gates,” says Saunders. “It’s amazing to think that he has actually seen one of our products in action.”

The Microsoft founder was so impressed by the invention that the Bill & Melinda Gates Foundation has now given the company a grant to develop a new range of smaller vaccine fridges with a cool life of up to 30 days, even in the tropics.

“They want to put these systems at the end of the cool chain, at clinics in the middle of nowhere,” says Tansley. “It was an impossible task and yet we’ve just trialled a device that has managed to maintain its temperature for 37 days.”

However, the applications for Tansley’s invention are far wider than vaccine transportation. Sure Chill is currently in talks with a number of beverage companies about rolling out their fridges in markets where the electricity supply is sporadic.

“People selling drinks have hugely ambitious targets and they won’t be able to meet them without reaching vast new populations in developing countries,” says Tansley.

In countries such as India and Brazil, shopkeepers routinely turn off their fridges and freezers when they turn off the lights at the end of the day.

“It’s a cultural norm that results in thousands of cases of food poisoning,” says Saunders. “That risk will be eliminated by this technology.

“And there’s the simple pleasure of a cold drink in a hot country,” he adds. “Something we all take for granted.”

The company recently signed a licensing agreement with Godrej, a white-goods manufacturer in India, to start mass-producing its technology. There is a strong pipeline of new deals in the offing, all protected by non-disclosure agreements.

“We’re following the Intel model,” says Saunders. “We want Sure Chill to be in every refrigerator.”

Tansley’s invention has been embraced by the Smart Grid movement, which is shortly to be rolled out across Europe and the US.

“Your fridge is the single biggest user of electricity in your home,” he says. “Smart Grid will allow generators to be turned off or turned down during peak times and reward consumers with lower energy costs.

“You can’t just turn off a telly or a cooker – you can dim lights a bit, but not much. With Sure Chill, you could power your fridge during the night and it would stay cold all day.”

Tansley is developing new Sure Chill models all the time, from tiny fridges to walk-in cold-rooms. “I can make it any size you like,” he says. “The technology is really flexible and we have potential licensees across scores of markets.”

Turnover expectations are being revised up each month on the back of the new deals.

However, Tansley’s ambitions remain chiefly humanitarian. “Millions of people have never had a fridge because there simply wasn’t consistent access to electricity,” he says. “Now these people can keep food cold, which will bring down incidence of all sorts of medical problems.

“There’s finally a product that meets the need. This is like the mobile phone revolution, only with cooling.”