Technology Benefits
Direct current
This is the new direct current technology that will help Chile in its energy transition.
The diagnosis is shared. The large amount of renewable energy produced in the Antofagasta Region cannot be transported in its entirety to the center of the country given the lack of new power lines, which has created a bottleneck in the National Electric System (SEN).
Precisely to solve this problem and allow Chile to meet its goal of decarbonizing the energy matrix by 2050, the Kimal – Lo Aguirre transmission project was born, which was tendered by the State through the National Electrical Coordinator and awarded to the company Conexión. .
One of the project’s innovations is the use of direct current, also called HVDC, to transport electrical energy. Although this technology is new in Chile, it has been used in countries such as Brazil, the United States, Canada, Norway, Sweden and China, which have a large geographical area and specific sources of renewable generation – such as Chile – and, therefore , require long lines that at the same time allow a robust, efficient and resilient transmission system.
The Kimal – Lo Aguirre project covers five regions, from Antofagasta to the Metropolitan Region, 29 communes and more than 160 locations.
It includes 1,343 km of line and two converter substations, one in María Elena, Antofagasta, and another in Pudahuel, Santiago. The one in the north will take the energy provided by the renewable plants and convert it into direct current to transport it along the line, while the one in the south will do the reverse process to deliver it to the electrical system.
It will have a power of 3000 MW, equivalent to a quarter of the daily demand of the country’s electrical system. In its construction, the experience of ISA and China Southern Power Grid (CSG) will be used, both shareholders of the company that will build the line and converter substations, and whose professionals actively participate in the project.
Differences
and advantages
But what is the difference between this technology and the current one?
First, a lower environmental impact, because to carry the same power in alternating current would require a safety strip 50% greater than that contemplated in Kimal – Lo Aguirre. This will imply the use of less space on the ground, and more importantly, it will reduce the impact on the biodiversity of the territory, both at the level of flora, fauna and communities.
At the same time, it will require fewer tons of towers, foundations and cables compared to an alternating current line, which accelerates the construction period, reducing the transfer of machinery, people and materials, reducing emissions, noise and intervention of roads in protected or remote areas.
It is more efficient for transporting energy, because it suffers fewer losses along the way given its characteristics. When transporting 3000 MW in alternating current, the loss could reach a power of 250 MW. Using direct current allows this figure to be reduced to 150 MW. To measure this factor, those 100 MW difference can supply more than 33 thousand homes.
When the project is in operation, the efficiency of use of renewable energy will improve considerably, reducing energy loss in northern Chile by around 50% and positively impacting the prices of the National Electric System (SEN).
Precisamente para resolver ese problema y permitir que Chile cumpla su meta de descarbonizar la matriz energética al año 2050, nació el proyecto de transmisión Kimal – Lo Aguirre
El cual fue licitado por el Estado a través del Coordinador Eléctrico Nacional y adjudicado a la empresa Conexión.
Una de las innovaciones del proyecto es el uso de corriente continua, también llamada HVDC por sus siglas en inglés, para transportar energía eléctrica. Si bien esta tecnología es nueva en Chile, ha sido utilizada en países como Brasil, Estados Unidos, Canadá, Noruega, Suecia y China, que cuentan con una gran extensión geográfica y focos puntuales de generación renovable –como Chile- y, por lo tanto, requieren líneas de gran longitud que a la vez permitan un sistema de transmisión robusto, eficiente y resiliente.
El proyecto Kimal – Lo Aguirre abarca cinco regiones, desde Antofagasta a la Región Metropolitana, 29 comunas y más de 160 localidades. Contempla 1.343 km de línea y dos subestaciones convertidoras, una en María Elena, Antofagasta, y otra en Pudahuel, Santiago. La del norte tomará la energía aportada por las centrales renovables y la convertirá en corriente continua para transportarla por la línea, mientras que la del sur hará el proceso inverso para entregarla al sistema eléctrico.
Tendrá una potencia de 3000 MW, equivalente a un cuarto de la demanda diaria del sistema eléctrico del país. En su construcción se aprovecharán la experiencia que tienen ISA y China Southern Power Grid (CSG), ambos accionistas de la empresa que levantará la línea y subestaciones convertidoras, y cuyos profesionales participan activamente en el proyecto.
Transmission lines
Energy in Chile is transported from generation sources to consumption centers through high-voltage transmission lines. There it is received by substations, where it is converted to low voltage for its end-user distribution.
As required by current national regulations, all transmission line projects must establish a safety strip to ensure that there are no safety risks to both people and the facilities that make up the line.
- Thanks to HVDC technology, the required fringe is smaller than for the set of alternating current lines that would transmit the same amount of power.
- To transport the same amount of power, alternating current lines would require a strip of about 120 meters wide. In the case of the Kimal – Lo Aguirre direct current line, it requires a minimum width of 77 meters. This width includes the entire strip, from end to end.
* The width of the safety strip will vary according to the conditions of the span to be analyzed, such as height above mean sea level (AMSL) and separation between structures.
Decarbonize
In Chile we are amidst an Energy Transition, incorporating more and more renewable energies and strengthening transmission systems, with more investments and new clean energy projects. The National Electric Coordinator (public agency) expressed the need to transmit the renewable energy currently being generated in the north of the country to energy consumption centers so to ensure an efficient supply and also for replacing the energy produced by fossil fuels (coal, oil, and gas), contributing to the decarbonization of our matrix by introducing clean energy.
Magnetic fields
A magnetic field is a force field created as a result of the movement of electric charges (flow of electricity). The flux decreases with the distance from the source causing the field.
Therefore, when defining the route of a transmission line, compliance with electromagnetic phenomena (electric and magnetic field, audible noise, radio interference) must be guaranteed, forbidding any building or human settlement within the safety strip.
Likewise, the Ministry of Health, which participates in the Environmental Impact Assessment System, has generated guidelines to carry out studies to rule out health impacts, such as noise, emissions, and electromagnetic fields, which must be included in the project design.
Direct current
Direct current refers to the continuous flow of electric charge through a conductor between two points of different potential and electric charge. It is the electric current that flows steadily in one direction, such as that flowing in a flashlight or any other battery-operated device.
The use of this current in a transmission line has economic, social, and environmental advantages.
- No need for intermediate substations.
- Lower energy losses.
- Quick power flow control.
- It helps to reduce Alternating Current system oscillations (which up to now is the only electric current used in Chile).
- Smaller security fringe.
- Less impact on the territory because fewer structures and conductors are needed.
The longer the distance of the transmission line, the lower the investment cost. Therefore, this first direct current line will be the longest in Chile to date.
The longer the transmission distance (km), the lower the energy losses (MW) of HVDC technology.
