Sun, wind and desert salts: Chile’s energy revolution against climate change

In the Atacama desert, the driest in the world located in northern Chile, thethe only solar thermal tower in Latin America, in turn a symbol of an ongoing energy revolution against climate change.

The imposing 240 meter construction It is one of the pillars of Chile’s ambitious green energy program launched in 2019 and aims to completely replace fossil fuels by 2040.

Together with the solar thermal production of Cerro Dominador, which Chileans compare it to Sauron’s tower from “The Lord of the Rings””, the Alba Project advances, a pioneer in the world in the conversion of a coal-fired thermoelectric power plant into a large storage system based on renewable energy.

Both plants, the first operational since 2021 and the second in its first phase of construction, are located in Antofagasta, a region approximately 1,300 km north of Santiago.

“A decade ago, no one would have imagined that more than a third of Chile’s energy would come from the sun and wind before 2030. It was seen as something ambitious and has already been surpassed,” the former Chilean Minister of the Environment. Chile Marcelo Mena.

Today 35.4% of the energy generated in Chile is wind and solar, while 37.2% It comes from water sources of the National Electricity System (SEN), which covers the vast majority of demand. Oil, coal and gas account for 26.9%.

“Very few countries in the world have been able to truly consolidate a renewable energy industry like Chile”, underlines Marta Alonso, director for South America of GES (Global Energy Services), a global provider of services for the wind and solar.

However, after the strong initial push, The process has slowed due to the lack of legislation to change the energy matrix, adds the renewable energy expert.

Perhaps one of the biggest obstacles to decarbonization is storage. Every type of energy, if produced and not used, is lost, as if it were an open tap.

“It’s a dilemma, because (storage) “It’s not a mature technology yet” Alonso underlines.

Chile has begun exploring an alternative that has already made its way to other parts of the world.

Both Cerro Dominador and Project Alba are powered by so-called solar salts, also extracted from the Atacama Desert, composed of potassium nitrate and sodium nitrate, which, melted and kept in a liquid state, allow energy to be stored.

“The case of Project Alba is unique in the world. It is the only existing Carnot (thermal storage) battery project of this scale outside a university,” Diego Pardow, Chilean Energy Minister, explains to AFP.

Thousands of mirrors

“Our projection is that coal plants will be eliminated” be replaced by solar thermal systems and for “the conversion of these plants into batteries like the Alba Project”, he adds.

In this way, Chile advances in the fight against the climate crisis in Latin America, one of the regions that, according to experts, emits the least CO2 in the world.

The Cerro Dominador tower It is surrounded by 10,600 mirrors or heliostats which form a sort of sunflower at their feet. It is the fourth plant of this type in the world and the only one in Latin America.

The promising solar salts circulate through artery-like conduits that connect to the tip of the structure, where mirrors that reflect sunlight are located They heat them up to 565 ºC.

They then travel down those same pipes to the water containers that generate the steam that drives the turbine, which in turn produces electricity. The plant has an installed capacity of 110 megawatts (MW).

“Thanks to the salts we managed to have a storage period of 17 hours”, explains Ivan Abella, director of corporate constructions of the Cerro Group.

Therefore, when “we stop having the energy source, the sun, we stored it in a reservoir with salts,” he adds.

The Alba project also aims to do this use the same technology to transform the modern coal-fired thermoelectric power plant of Angamos, owned by the AES company, which came into operation in 2011.

“By maintaining half of the assets of this plant, which is practically new, (Angamos) would be transformed into a battery, which would use renewable electricity,” Vanni Boggio, director of the Northern Complex of AES Chile, explains to AFP.

Alba will be supplied with photovoltaic and wind energy which in turn will heat the salts that will replace the fossil fuels they operate with today, maintain its current power of 560 MW.

Alba “is a very interesting project (…) We must follow it closely because it could be a solution” even if it is not a panacea, clarifies the GES analyst.

AFP agency