Camanchaca, a desert ally for Enel Green Power Chile's solar plants

Published on Monday, 21 December 2020

It all started in Chañares

Diego de Almagro is a city and municipality of 14,000 inhabitants located 149 kilometers north of Copiapó, in the Atacama region. Construction of the Chañares photovoltaic power station began close by in 2014. Currently, the plant has an installed capacity of 40 MW and a generation capacity of up to 94 GWh per year.

A new chapter in the history of solar energy in Chile began in 2016, according to Roberto Alhucema, head of O&M Solar Chile. “Thanks to the Efficiency Recovery Action Plan at the Chañares Plant, we are now aware of the large levels of relative humidity in the atmosphere and also of the problem of particle deposition on horizontal planes and cementation caused by humidity that forms on the photovoltaic panels.” There was work to be done. And they started looking for solutions.

Since the beginning of the millennium, solar power generation has been developed using tracking structures that maximize the amount of energy generated by following the movement of the sun from east to west. By default, the panels were originally developed to lie flat at zero degrees (horizontally) at night in order to avoid wind resistance and this could not be modified.

Leaving them in this position all night left them exposed to being covered with sediment which could then collect water condensation from the camanchaca.

Something had to be done. "Along with the manufacturers of the trackers we worked to modify the system to allow the solar panels to rest at other angles at night," says Alhucema.

Different resting positions were tested until it was decided to leave them at 45°.

Simple modification, major benefits

Since then, all of Enel Green Power Chile's photovoltaic plants have followed in Chañares’ footsteps. The simple change made to the resting position of the panels quickly led to improvements in results, especially in terms of water use.

To give you an idea, a single solar panel requires about 0.5 liters of water for cleaning and Enel Green Power Chile has 1,701,757 solar panels. Today, the company has seen savings in hundreds of thousands of liters of water, which is now available for other uses, especially for communities in the Atacama Desert where water is an increasingly scarce resource.

The solar panels used to have to be cleaned 4 to 6 times a year. Since the company started using the camanchaca to do its cleaning, the panels now only need to be cleaned 1 to 2 times a year. Dirt accumulation on the panels fell from 10% to less than 1%, which has led to significant reductions in operating costs. The camanchaca always existed and today the company is taking advantage of it.

In concrete numbers, according to Enel Green Power Chile's own studies:

  • A 60-80% reduction in water consumption and cleaning costs in areas where camanchaca (sea humidity) is present, due to less deposition of particles on an inclined plane and self-cleaning in times of high humidity (Bolivian winter)
  • A 40-60% reduction in water consumption and cleaning costs in areas without camanchaca due to less deposition of particles on an inclined plane

What is next?

The objective for what comes next is clear - to convert Enel Green Power's photovoltaic plants into self-sustaining power stations.

Today, we are studying how to collect the camanchaca water moisture that cleans solar panels and to reuse it.

The so-called "Atmospheric Water Collection Project," is at the testing phase to first identify which areas have the highest concentration of camanchaca and what would be the optimal method to collect this water vapor.

The aim is to collect water for use in our power generation processes as well provide it to the surrounding communities where the plants are located. We believe we can do all of this using the camanchaca water vapor that appears every day on our coasts.

Working with the community

Another initiative in Diego de Almagro is the CIDER (Renewable Energies Interpretation Center), which was built within the framework of Sustainable Development Goal 7 of the United Nations' 17 Sustainable Development Goals.

Work with the Diego de Almagro community has gone from strength to strength over the years. By sharing their experience in working together, the Diego de Almagro municipality and Enel Green Power have demonstrated the strategic importance of renewable energies for sustainable power generation in Chile. Indeed, the municipality allowed Enel Green Power to renovate a 110 m2 old hangar located in the city center and turn it into a renewable energies interpretation center (CIDER).

Throughout the year, CIDER holds a series of workshops and activities aimed especially at elementary and middle school students but which are also open to the entire community. The activities touch on issues related to the operation and use of non-conventional renewable energy, energy efficiency, installation and maintenance of local solar panels, recycling and the reuse of materials. Enel Green Power also organizes guided visits of its plants.

Enel Green Power's head of community relations Leonardo Araya, believes that CIDER is making an important contribution to the community.

"We are helping to teach students in the Diego de Almagro municipality about non-conventional renewable energy and energy efficiency and our aim is to eventually incorporate this subject area into their school curriculum."

The center also provides tools and skill sets to teachers and educators to help promote recycling in the municipality. CIDER is making a real contribution to the growth in theoretical and practical knowledge of renewable energy and is helping pave the way for a transition to green power and greater care of our planet.