Wake up daily to our latest coverage of business done better, directly in your inbox.


Get your weekly dose of analysis on rising corporate activism.


The best of solutions journalism in the sustainability space, published monthly.

Select Newsletter

By signing up you agree to our privacy policy. You can opt out anytime.

Gina-Marie Cheeseman headshot

Recycled Aluminum Could Allow for Next-Gen Energy Storage

Energy Storage

What happens to renewable energy when the sun does not shine, or the wind does not blow? One answer to the question is to use diesel generators to cover the times when solar panels or wind turbines stop providing electricity - but the use of generators ends up creating more carbon emissions. Another answer is to store power that the sun generates in batteries. However, that solution creates a recycling problem as batteries need rare earth minerals. One company offers what it says is a more environmentally friendly energy storage option: store solar power, or power from any source for that matter, without batteries by using an alternative manufactured out of recycled aluminum.

That company is Azelio, a Swedish energy startup. The first site to use the company’s energy storage technology is at the Noor Ouarzazate solar complex in Morocco, a 580-megawatt (MW) power plant. Azelio’s technology helps to supply renewable power around the clock at this solar complex, one of the largest concentrated solar plants in the world.

Azelio inaugurated its renewable energy storage system Moroccan solar plant earlier this month in an event co-hosted with the Moroccan Agency for Sustainable Energy (Masen). Government representatives from several countries attended, along with leaders from the World Bank and the International Finance Corporation.

“Being present on one of the world’s leading arenas for renewable energy marks a big step for Azelio and is the platform from where we take the next step in becoming a global industrial player,” said Jonas Eklind, CEO of Azelio.

Azelio’s technology scored enthusiasm for what the company says is its energy storage technology’s ability to have a 90 percent round-trip efficiency. As the renewables news site Recharge explained, if the technology works as Azelio says it does, then only 10 percent of the energy stored during this process is lost.

“Our collaboration with Azelio is a good example of Masen’s R&D strategy to evaluate, co-develop and promote disruptive solutions,” said Mustapha Bakkoury, CEO of Masen. “We are proud to have Azelio’s energy storage represented on Noor Ouarzazate solar complex.”

The basics of Azelio’s thermal storage technology

Azelio’s operations run in a former Volvo factory, where it now manufactures its thermal energy storage system – which, once it’s complete, looks as if it is housed in a shipping container.

The company uses recycled aluminum in the system to store energy in the form of heat. Aluminum has a high degree of energy density which enables local energy production at all hours of the day, even in remote areas lacking electricity. The use of aluminum could work similarly to the use of molten salt for energy storage at some solar power installations.

There is a clear need for technologies such as that of Azelio’s as millions of people globally lack access to an electrical grid. That’s including 57 percent of the population in sub-Saharan Africa and almost 10 percent of the population in Asia.

Aluminum is the third most common element and the most common metal in the earth’s crust. Aluminum’s largest environmental impact comes from the energy used to manufacture this metal, but such the use of recycled aluminum helps reduce this impact. The stored energy in the recycled aluminum converts into electricity on-demand with the company’s modern version of a Stirling engine.

Is this system scalable?

Azelio describes the engine as being “unique in its ability to provide incredibly efficient conversion of thermal energy into a mechanical movement that can generate electricity.” The company insists its system is scalable from 100 kilowatts (KW) to 100 megawatts and can supply electricity for a wide variety of customers, including hospitals, factories, mining operations or a small community.

Azelio says it has successfully demonstrated that its technology is feasible in 2018. Since then, the company received interest for power systems that together generate almost 4 gigawatts of clean power.

But as Recharge’s Leigh Collins recently pointed out, Azelio has not been forthcoming about neither the price of this system nor the costs of storing power. The company has also not disclosed how big its system is at the Morocco test site. “It is therefore difficult to compare Azelio’s system with other build-anywhere long-duration intermittent energy storage . . . technologies,” wrote Collins.

Last fall, the company announced it would start another energy storage project at Abu Dhabi’s Masdar. In the meantime, the company says it has more plans for commercial installations of its technology later this year and will have the ability to launch mass production of its energy storage systems 2021.

Image credits: Azelio

Gina-Marie Cheeseman headshot

Gina-Marie is a freelance writer and journalist armed with a degree in journalism, and a passion for social justice, including the environment and sustainability. She writes for various websites, and has made the 75+ Environmentalists to Follow list by Mashable.com.

Read more stories by Gina-Marie Cheeseman