The electricity grid systems include three distinct components, often hundreds or thousands of miles apart—generation, transmission, and distribution. In many cases, the location of the generation and the concentration of the consumption of power are quite distant from each other. This has been the case in Turkey particularly when the country was hugely dependent on power generation by using large dams and coal facilities. Major water sources and large coal reserves are mostly in the eastern part of the country whereas the population and the industry are in the west and the southwest of the country.
The transmission challenge due to the distance between the source and the consumption and the need for balancing the power distribution between the seasons could only be solved with an interconnected grid system. Turkey was depending on regional grid systems until 1952 when the first long-distance transmission line was completed. Currently, the whole country is covered by a fully interconnected grid system. The grid runs at 400 kV (dark lines on the map below) and 154 kV, and there are over 700 transmission grid substations. Transmission costs, including losses and operation costs, are shared equally between the producer and consumer. There are 11 international interconnectors with all of Turkey’s neighbours by land except Armenia, with which a connection is expected to be set up in the coming years.
Turkey’s backbone transmission lines connect to 21 distribution grids operated by private companies as shown on the map below. These 21 distribution grid companies operate approximately 71,000 Km of transmission lines. Electricity at voltages up to 36 kV is distributed by regional companies and many organized industrial zones. One of the aims of distribution system operators or electric distribution companies is to increase the efficiency of the existing grids by either replacing the old transformers or lines and/or installing smart grid systems.
There are over a million kilometres of distribution lines, of which about 80% are overhead lines and the rest are underground cables. The average losses across all distribution networks (including technical and non-technical) are around 12%. The losses are far higher in the eastern and south-eastern parts of the country than in the rest. The estimated System Average Interruption Duration Index (The metric for the breakdown) is worse than the average of European countries.
Each year, about 300 TWh of electricity is used in Turkey. Due to air conditioning demand peaks in summer, August is the highest, and February is the lowest. Total national consumption divided by the population is under 4,000 kWh a year, much below the average of around 10,000 kWh a year for other OECD countries in Europe, but half as much as the global average.
A substantial portion of the transmission lines and most of the transformers need to be replaced by new and high-capacity ones as energy demand is continuously increasing. The old system components are the major reasons for the breakdowns. Furthermore, the old transmission/distribution lines, transformers, and substations are one of the major reasons for forest fires during hot summer patches mainly because of the surging power demand for the AC units/systems.
The percentage contribution of renewable energy sources is increasing. Luckily, most of the renewable energy generation plants (wind and solar) are in the western and central parts of the country, substantially reducing the dependence on the high voltage transmission lines. The solar and wind power plants are also connected to substation transformers to feed the interconnected grid. The major challenge and the task of distribution system operators or electric distribution companies are to increase the efficiency of the existing grids by either replacing the old transformers or lines and/or installing smart-grid systems to decrease grid losses and to optimize demand control, microgrid dispatching, reactive power support, frequency control, and dispatch management.
Emission levels will inevitably decrease over time due to the upgrading of the grid system and its components as well as the increasing share of renewable sources.
This Post was submitted by Climate Scorecard Turkey Country Manager Dr. Semih Ergur