Icelandic artist Olafur Eliasson has previewed a third design in his series of solar-powered mini lamps made for people without access to reliable energy.

Eliasson gave a sneak peek of his latest Little Sun lamp during his talk at last week's Design Indaba conference in Cape Town.

The Little Sun Diamond has a faceted form that distinguishes it from the original Little Sun, with its cartoonish yellow frame, and the Little Sun Charge, a flatter blue design that doubles as a charger.

Like the original product, the Little Sun Diamond is small enough to fit in a pocket, and can produce four hours of light after five hours of charging.

Eliasson's hope for the Little Sun project is to bring light to people in remote locations and reduce their reliance on hazardous kerosene lanterns.

However, he received feedback that the original Little Sun's resemblance to a children's toy was putting off some customers, so he created the Little Sun Diamond – a more minimal design without any bright colours.

The Little Sun Diamond can alternate between two types of light: a concentrated reading-style light, and "a magical, sparkling glow" akin to that thrown from a mirror ball.

On stage at Design Indaba, Eliasson dubbed it a "party light". "They loved this idea – let's take back the diamonds," said Eliasson of the response to the product testing.

Eliasson is best known for his monumental installations based around light and optical illusions. In 2003 he bought a monumental glowing sun to the Tate Modern Turbine Hall – a project which partly inspired the Little Sun brand.

The first of the lamps was launched in 2012, while the Little Sun Charge was realised through a Kickstarter crowdfunding campaign in 2015.

While the products are designed primarily for communities without electricity, Little Sun also targets a market of "urban explorers" in more affluent countries. Their purchases help to offset the cost of the lamps elsewhere, so they can be sold at a locally affordable price.

"It's not easy," Eliasson told the audience at Design Indaba. "We have now reached 280,000 lamps. We sold 220,000 in Europe, primarily, some in America, and we have financed a economically sustainable model which is about being not an aid-funded project but a micro-economy with all kinds of different collaborations with NGO and private sector."

By using the Little Suns, people save money that they would otherwise have been spending on petroleum – money that they can spend elsewhere in the economy.

"[Because of Little Sun] $55 million was released for things other than petroleum," Eliasson said. "So this is such a small lamp. And yet it is the biggest project I've started on."

The original design, shown here in this film, could produce five hours of light when charged in the sun for five hours

Eliasson was among a host of industry figures to speak at the Design Indaba conference, which took place at Cape Town's Artscape Theatre from 1 to 3 March 2017.