It was a surreal feeling for Stanford student Francisco Torrealba. Having climbed a 2,000 meter coastal cliff north of Chilean city Tocopilla, he looked out over the expanse of clouds underfoot and the vast South Pacific Ocean stretching into the horizon.
It was June 2011 and Torrealba was struck by the region’s awesome potential for large scale electricity storage in natural depressions occurring on seaside cliffs high above the inhospitable Atacama Desert.
A month later, Torrealba and fellow Stanford student Juan Andres Camus registered their fledgling company Energia Valhalla Spa - the vehicle to realize their vision of combining solar power with ‘pumped storage’ hydro-electric plants to deliver power on a continuous basis to Chile.
Helping their efforts was the plunge in the costs of solar panels and plants.
“The installation of photovoltaic panels on the surface of only 6% of the Atacama Desert would be sufficient to satisfy the entire demand for electricity in South America,” say the Valhalla founders. “However, solar energy is intermittent and is not available during Chile’s peak consumption hours which occur at around 10 pm.”
“Our company is developing pumped storage hydroelectric plants, equivalent to large “water batteries,” which will allow us to store energy in an exceptionally economic manner and also to transform solar energy into an electricity source which is available 24 hours a day, 7 days a week,” they say.
Their US$400 million project, Espejo de Tarapacá (EdT), is one of the most innovative infrastructure projects in the world and comprises a 300 MW pump hydro plant that sends seawater 600 meters up for storage in natural concavities stretching over 375 hectares (capacity equivalent to 22,000 Olympic pools and area equivalent to 500 soccer fields). These depressions are believed to be very ancient lakes that have long since dried up and are now just a desert.
The hydro pump operates on energy generated during the day by a solar plant. At night, the stored water reverses flow and gushes back down to the sea, driving hydroelectric turbines and generating power.
According to Camus, who was speaking to Reuters, the project can provide electricity continuously for nine days if the concavities are filled to capacity.
Valhalla announced last week that EdT has received environmental clearance for its project. However, approval from Chilean regulators is still awaited for the 600MW, US$500 million Cielos de Tarapaca solar panel energy project that will supply the solar energy required to operate EdT’s hydro pump.
When complete, most of EdT’s energy will be supplied to mining companies in the Iquique area in northern Chile.
Title image credit: Valhalla/latercera