The Atacama Desert is one of the driest places on our planet; it is a 128,000 square kilometers (49,000 square miles) plateau that in some places sees less than three millimeters (0.12 inches) of rain in an entire year. With this in mind, it may seem peculiar that the Chilean company Valhalla are planning to build a huge hydroelectric power plant right on the edge of it.
This hydroelectric plant will be fairly similar in design to many others around the world. Water from a great height will be dropped down through steep slopes, causing turbines to spin and generate energy; the water eventually flows out to a river or into the sea. The Valhalla project isn’t technically too different from this basic design.
The $400 million (£260 million) project will take advantage of two of the desert’s other prominent features, other than its distinct lack of rain. The first is the desert’s effective border with the Pacific Ocean to the west: the Andes mountains, the longest continental mountain range in the world at 7,000 kilometers (4,300 miles) in length.
At an average height of 4,000 meters (13,000 feet), they provide plenty of sufficient elevation for a hydroelectric dam. Seawater will be pumped up into the mountains, allowed to rest there for very long periods of time, and released downstream through the turbines when electricity is required to be generated.
The two mountaintop reservoirs can contain 22,000 Olympic swimming pools of water, roughly equivalent to 55 million cubic meters (1.9 billion cubic feet). This impressive storage capacity means that electricity can be generated 24 hours a day.
Image credit: The location of the proposed hydroelectric power plant. Valhalla/Google Maps
The entire complex will have a capacity of 300 megawatts, comparable to the advanced solar power plant currently being built in Morocco. This will be enough to power three of Chile’s provinces – ones that rely heavily on the import of fossil fuels.
Of course, pumping the water up into the mountains will still require energy, and this is where the second characteristic of the Atacama Desert comes in: its reliably sunny skies. According to the company’s website, they will use “reversible turbines” within a “cave of machines,” powered by solar energy, to pump the water up into the mountain reservoirs at a rate of 45 cubic meters (1,590 cubic feet) each day.
The project has been given the go ahead by environmental agencies, but they are still looking for investors in the project. Valhalla hope to complete the construction in three and a half years’ time, starting late next year.