Article Source: IMechE
A Bill Gates-backed start-up claims to have generated temperatures hotter than 1,000ºC using just concentrated sunlight.
Unlike conventional concentrated solar power, which is used for electricity generation, CEO Bill Gross said Heliogen’s process is focused on tackling “the other 75% of energy demand” – fossil fuels used in industrial processes and transport.
Previous commercial systems were designed for temperatures up to 565ºC, which is useful for power generation but insufficient for many industrial processes. Many of these applications, such as steel production, require much higher temperatures that have traditionally been reached through burning fossil fuels.
Heliogen said it achieved the much higher temperature in Lancaster, California, thanks to technology that uses advanced computer vision software to “hyper-accurately align a large array of mirrors to reflect sunlight to a single target”. Conventional systems reflect the light onto fluids such as molten salt, which can store heat if the weather changes and it is no longer sunny.
Professional Engineering contacted Heliogen for more information on the technology, including how it differs from conventional installations, how the heat will be utilised in industry and if processes could be halted by cloudy weather.
The mirrors reflect light onto a target on the installation tower (Credit: Heliogen)
“The world has a limited window to dramatically reduce greenhouse gas emissions,” said the company’s founder Gross. “We’ve made great strides in deploying clean energy in our electricity system. But electricity accounts for less than a quarter of global energy demand. Heliogen represents a technological leap forward in addressing the other 75% of energy demand – the use of fossil fuels for industrial processes and transportation. With low-cost, ultra-high temperature process heat, we have an opportunity to make meaningful contributions to solving the climate crisis.”
Promising applications include cement production, which alone accounts for more than 7% of global CO2 emissions.
The company said it aims to reach temperatures up to 1,500ºC. At that temperature, the process could split CO2 and water to make completely fossil-free fuels such as hydrogen or syngas.
“Today, industrial processes like those used to make cement, steel and other materials are responsible for more than a fifth of all emissions,” said Bill Gates. “These materials are everywhere in our lives but we don’t have any proven breakthroughs that will give us affordable, zero-carbon versions of them. If we’re going to get to zero-carbon emissions overall, we have a lot of inventing to do. I’m pleased to have been an early backer of Bill Gross’s novel solar concentration technology. Its capacity to achieve the high temperatures required for these processes is a promising development in the quest to one day replace fossil fuel.”