Journey in the Desert of “Two Winters”

Published on Tuesday, 4 July 2017

“The structure is made up of two units, each with an installed capacity of 24 MW. It’s the first geothermal plant in all of South America, and the first industrial-sized high-enthalpy geothermal plant in the world to be built at such a high altitude.”

A ten-year-long project

Martino Pasti is the Project Leader at Cerro Pabellón, a project that Enel Green Power launched back in 2006. Because of its extreme location and the high technological and human effort involved, we’ve risked seeing fail and end up on the shelf many times over the years. But that’s not what happened.

“Reaching the synchronisation of the second and last unit of Cerro Pabellón is a key accomplishment”, explains Martino Pasti, who is still leading the project in Chile. “The two units were started up in record time and almost simultaneously, an undertaking that involved massive effort from the entire EGP team, but that has led to enormous satisfaction”.

Now that the second synchronisation is complete, “we have to finish the connection of the geothermal wells we are still drilling with the so-called Gathering System, an innovative transport system of geothermal fluid that will take us a few more months to finish”.

“The level of technology and automation we applied at Cerro Pabellón is higher than at any other plant of ours in the world. This approached turned out to be necessary because of the extreme conditions there and to reach the goal of minimising Operations activities and maximising reliability.”

– Martino Pasti

Creating energy at the ends of the earth

The climate of the Atacama Desert is characterised by two critical events a year. On one hand, there’s the “traditional” winter, which lasts from June to September, when there are temperatures of up to 30 degrees below zero and very strong thermal excursions, even of 20 degrees between the day and night.

On the other hand, there is the so-called “Bolivian winter” which happens in the middle of summer, between December and March. This is a unique climatic phenomenon that generates violent rainfall and flooding, often accompanied by snow, hail and electrical storms.

“But that’s not all”, adds Martino Pasti. “At Cerro Pabellón, oxygen saturation is very low because of reduced atmospheric pressure, so all the people arriving at the plant undergo considerable physical stress that requires a period of acclimatisation. This is why the camp is located about 30 kilometres from the plant and at an altitude of 3,600 metres: sleeping at 4,500 metres would be very complicated”.

“At Cerro Pabellon, we work 9x9 or 14x14 shifts. Every 9 or 14 working days, we must take 9 or 14 days of rest. This obviously involves a massive amount of resources.”

– Martino Pasti

Unprecedented Innovation

At Cerro Pabellón, we are able to produce zero-emission energy 24 hours a day, without needing diesel generators. We can do this thanks to an innovative, commercial "plug-and-play" microgrid, totally “emission-free” and powered by photovoltaic solar and by hydrogen and lithium storage systems. The plant, unique in all the world, partly responds to the energy needs of the base camp, which hosts more than 600 technicians.

“We believed in Cerro Pabellon and we’ve brought home results that many thought were impossible. Now that the plant has become reality and is almost complete, these results make us very proud. It’s an experience that I’ll take with me for the rest of my life.”

– Martino Pasti

The microgrid is a cutting edge innovation project based on a hybrid storage system (HyESS) that includes a 125-kWp solar photovoltaic system, supported by a 450-kWh hydrogen storage system and 132-kWh lithium batteries. Furthermore, an innovative control system optimises the flows of energy produced by the photovoltaic modules and ensures that those flows are shared efficiently between the two storage systems in order to guarantee the constant availability of energy.