Swedish startup turns waste heat into clean energy

Swedish startup turns waste heat into clean energy
Could the solution to the world's climate crisis be simpler than we think? A Swedish team is turning wasted heat into clean energy - in a sustainable and low-cost manner.

Up to 50 percent of the energy in the world is waste heat, produced by industrial machines, which doesn't end up being used. Large factories frequently release hot water from production straight into the sea – letting the energy literally run away.

Swedish company Climeon Oceans has developed a technique for industries and vessels to harness the energy and produce their own clean energy source.

When Swedish civil engineer Thomas Öström visited China, he could barely breathe due to the air pollution.

“The smog lay like a blanket over Peking,” he recalls. “I just thought, it can't go on like this.”

Back home in Sweden, he started thinking seriously about what could be done about the climate crisis facing the world today.

According to his five-year-old son, the solution was simple: “Make dirty energy expensive and clean energy cheap.”

That's not really the way the world works – but could it be? Öström started brainstorming with his chemist neighbour Joachim Karthäuser – and with help from Sweden's Royal Institute of Technology (KTH), the duo's ideas are starting to have an impact.

The two Swedish dads started by drawing and doodling climate solutions with their children's crayons or chalk on the sidewalk between their homes. And when they came up with something that they thought might actually work, they went to the Swedish Energy Agency (Energimyndigheten).

“We thought the physicist there would just shoot us down entirely,” Öström says. “But he actually thought it was a good idea.”

The idea was that waste heat from industries and motors could be transformed into clean, usable energy. Hot water is frequently dumped straight into the sea – and Öström and Karthäuser thought that maybe that water could be used to heat a special vehicle fluid which could then be used as fuel for ships.

“The technology converts ‘cold’ heat to electricity with over 10% efficiency at a 90C heat source and a 20C cold source,” the company’s website states. “Theoretically the solutions can deliver up to 14% efficiency at 120C. The system is compact in size starting from 2 x 2 x 2 m and includes all needed components to produce electricity. Just add hot and cold water.”

Of course, the team won't reveal what the special fluid is – that's a secret. “We tested 3,600 different substances,” Öström says.

But before they truly began work, the Energy Agency recommended they test the idea. Per Lundqvist, professor of energy technology at KTH, stepped in.

“He gave us the chance to conduct tests and gradually build a prototype in KTH's lab,” Öström says. “Without his engagement, there would be no Climeon Ocean today.”

The team's secret solution creates 2 bars of pressure when it's boiled – about as much as the air pressure in a bicycle tyre, on one side of a turbine. The opposing side is becomes a vacuum when the special fluid is chilled with cold water and sprayed out. Despite the very low pressure, the turbine functions effectively.

“It's not the amount of pressure that's really important but rather the way the pressure is divided,” Öström explains. “In this case 2 bars of pressure divided into 0.3 bars. It's the difference between the low pressure on one side and the lack of pressure on the other side which creates the effect.”

The turbines drive a generator which produces electricity. By using such turbines, a factory (or shipping vessel) can produce its own electricity using the leftover hot water from other industries.

“The really clever part is that the more electricity a factory needs, the more electricity it also produces, since high levels of production create even more waste heat,” Öström remarks. “If the water waste is 90 degrees Celsius, then that's enough to save 10 percent of the electric use.”

The first customers to utilize the Climeon Ocean system were the Viking Line's ship Viking Grace and SSAB in the Swedish town of Borlänge. The cruise ship Viking Grace uses the heat generated by the motor, which otherwise would run out into the sea, and transforms it into electricity to be used on the boat. 

The machines are only a few metres squared, enabling several to be used on one vessel.

“At first we were testing with a module that would save about 200 tonnes of fuel per year on the ship,” Öström says. “But actually, there was room for three modules, meaning that they can save 600 tonnes of fuel a year – decreasing the carbon dioxide release by 1500 tonnes a year. That's the equivalent of 30,000 trees growing for 30 years.”

A critical part of the design is its size and low cost.

“In the end I think money still makes the world go round,” Öström says. “Unfortunately, it's rare that investments are made just for the sake of the environment. But if a company sees that it can save money by using our machine, then they'll invest. So the important thing, our goal, is to create a cost-effective solution which is also good for the environment.”

Climeaon is now expanding and plans to double the size of its team in 2016. “It's great that so many people believe in us,” Öström says.

Read more about the revolutionary Climeon  technology at their website.