In the first part of the year, there were 188 hours of zero marginal cost in the former SING. Although this figure dropped in the winter months, the phenomenon is expected to occur again this summer.

One of the most relevant milestones in Chile’s electrical development was the interconnection of the SIC and the SING, which became a single National Electric System (SEN).

Ten months after the event, the effects have been diverse. Among the most striking, according to an analysis prepared by the consulting firm Systep, are the changes in electricity prices in regions III and IV, that is, in the north of the former SIC.

In these areas, once the systems were combined, the average marginal costs increased by US$18.6 and US$11.5 per MWh, respectively, which represents increases of 56% and 36%, respectively.

This is due to the fact that prior to the interconnection, during several hours of the day, the system operated at $0 marginal cost. But after that milestone, since the energy can be exported to the SING, there is no longer excess energy and it can be evacuated. “The cost was more aligned with the north,” explained Systep’s general manager, Rodrigo Jiménez.

However, the zero cost was transferred to the former SING. There, in the first part of the year, 188 hours with zero marginal cost were observed. And although this figure dropped in the winter months, Systep warns that the high summer radiation could cause this effect to be repeated.

Energy discharge

Another important effect of the SEN was the reduction of discharges from NCRE plants. In the case of solar, they dropped from 24% in April 2017 to 5% in 2018. In the case of wind energy, the drop was from 12% to 3%.

The document emphasizes that the full benefits of this interconnection will only be appreciated when the Cardones-Polpaico line is 100% operational. This should take place in December, according to InterChile, the company in charge of the project.