The figures so far this year for renewable energy curtailment, i.e. energy that could not be used, show levels never seen before, according to figures at the end of July. In this sense, 2,206 GWh have not been used to date, a figure that is more than six times what was lost in the same period during 2021.

With the indicator as it currently stands, the whole volume of the previous year -where 1,647 GWh were lost- has already been far exceeded.

One of the reasons explaining this situation is the lack of transmission lines to transport renewable energy – its contribution has grown by 40% in the last 12 months- since most of this new capacity has been located mainly to the north of the Quillota substation, where relevant limitations have been observed at the transmission level mainly during the day.

Carlos Suazo, founder of the consulting firm Spec, recalls that although curtailment is relatively minor when compared to the energy being injected by renewable sources, the economic effects generated by this turn out to be relevant, since the price signal it activates is a zero marginal cost at a local level.

“This undoubtedly generates a greater risk for projects currently behind congestion, with greater impact when these are financially structured under energy contract schemes whose supply is not in the same area. This has spurred for a large part of the industry to couple renewable projects with the joint development of storage systems”, comments Suazo.

The expert also points out that curtailment is an endemic situation in electricity systems, since grids are not planned to minimize the level of curtailment in the system, so it is relatively normal to observe this phenomenon.

But he describes a series of alternatives to address this situation, for instance: evaluating the postponement of maintenance work on critical sections of the network during summer time, operation scheduling and management of hot starts improvements, operational parameters review, and improvements in the demand and renewable resources forecasting process.

However, it is expected this figure will continue to rise for the rest of the year, since according to data from the Coordinator, it is estimated that about 4,000 MW of photovoltaic projects will come into operation by the end of the year, which, if materialized, will result in levels of curtailment that will far exceed what was seen in the last quarter of 2021.

Transmission

Given this situation, the Association of Transmission Companies comments that for both the short and medium term, the companies in the trade are proposing works to be included in the expansion plans that will allow better use of the existing infrastructure.

“The fundamental thing here is that whatever is proposed must be compatible with the system’s long-term development. To prevent us from continuing to have high levels of curtailment in the coming years – which is undoubtedly a critical problem – it is vital to plan transmission adequately with this horizon in mind; and, of course, to improve as soon as possible the signals necessary for investments to materialize”, says the executive director of Transmisoras de Chile, Javier Tapia.

Improving this type of infrastructure is essential to meet the country’s different objectives, both in terms of decarbonization and carbon neutrality. “Chile has the great challenge of being a carbon-neutral country by 2050 to face the environmental crisis we are experiencing. To achieve this, it is essential to incorporate transmission systems to boost and take advantage of the clean energies generated, mainly in the north of Chile, currently being lost due to the lack of systems that can take them to areas of consumption”, explains Sebastián Fernández, general manager of Conexión Energía, the firm in charge of the Kimal-Lo Aguirre line construction.