Chile: Mining is beset by energy-supply problems and high prices

At the outset of the last decade, Chile was forced to make sudden changes to its energy matrix following the announcement that gas supplies from Argentina, which had initially been expected to cover a large part of Chile's needs and at low prices, would not be available even remotely in the amounts foreseen. Chile opted for coal, built coal-fired power stations and switched to fuel oil in power stations that had been initially designed to run on gas.

In 2010, coal-based generation in the country's main energy systems-the Sistema Interconectado del Norte Grande (SING, for short) and the Sistema Interconectado Central (SIC)-accounted for 30% of total demand; gas accounted for 20% and oil 12%. Hydro production came to 35% and other renewables provided 3%. In all, 62% of the total demand was met by fossil fuels, a figure that in the regions covered by the SING system (northern Chile, where most of the country's copper mining industry is concentrated) comes to 97% owing to an almost total lack of hydro production. 

As a result, energy prices have risen and so too have emissions. It's a situation that calls for medium- and long-term solutions.

Renewables as an alternative

Mining companies are building new coal-fired power stations; they account for 62% of the requested power for new facilities over the next few years.

From an environmental point-of view, hopes currently rest on the possibility that the remaining 38% of projects will be renewables-based.

Some of those initiatives will be carried out by mining companies that have already set up wind farms aimed at reducing their emissions and which have introduced policies that set out to make their processes more energyefficient. But the country's enormous possibilities in terms of making the most of its solar resources-solar radiation rates in Northern Chile, where most of the country's copper mining is located, are among the highest anywhere on the planet-open the door to new alternatives as a way of guaranteeing the mining industry's energy needs.

Solar thermal energy with heat storage: an option for the sector

Solar thermal technology coupled with thermal storage devices are one of the renewables options with the greatest potential for development in Chile and other countries. In this type of installations, a fluid, usually nitrate salts with a large capacity for absorbing heat, is heated to extremely high temperatures by solar radiation and the heat is accumulated in a storage tank. From there, the fluid goes to an interchange where the water is turned into steam and makes its way to a turbine connected to a generator that produces electricity.

Thanks to this thermal storage system, energy can be produced even in the absence of radiation and for several hours at a time, which is key to ensuring an uninterrupted energy supply. Moreover, the estimated price will not be far off the real price per kWh paid by Chile's mining companies for energy produced in coal- or gas-fired power stations.

Related articles:

• ACCIONA delivers renewable energy solutions for the mining industry
• Australia