Electrical distribution in Thailand

Photo by M.O. Stevens, CC BY 3.0

As a Renewable Energies student at SRH, it is normal to wonder how the energy generation and distribution works in another country. When I was in Thailand, I saw that electric cables were still above ground unlike in Germany. However, being a total nerd, I had to find out more about where those cables came from and what the original energy source was. Thanks to NT from NCC (National Control Center – see my previous blog entry), I was able to understand the general idea of the system a little more.

By Vanda Friedrichs

The state-owned enterprise Electricity Generating Authority of Thailand (EGAT) is the main provider and producer of electricity in Thailand, generating about 45 % (2015) of the electricity. So where do the other 55% come from? From private owned companies in Thailand, the IPP (Independent Power Producers) and SPP (Small Power Producers), and imports. The IPP have power plants that exceed the total capacity of 90MW, while the SPPs generate anything below that. They all sell their generated electricity to EGAT. That sold energy, along with electricity generated by EGAT, is distributed by EGAT to the Metropolitan Electricity Authority (MEA) for Bangkok and its suburb regions, and to the Provincial Electricity Authority (PEA) for the different provinces in Thailand. The MEA and PEA have substations throughout their regions to distribute the electricity to houses along transmission lines. A summary of the electricity supply would look like this:



In 2014, EGAT produced 47% of Thailand’s electricity, the IPPs produced about 39%, the SPPs produced 7%, and 7% electricity was imported. The total contract capacity of that year was around 32,780 MW.

The question, however, still stands. Where does the energy originate from? Most of the electricity produced by EGAT derives from natural gas that comes from the gas fields on-shore and off-shore in the Gulf of Thailand. There are other types of resources that are far less abundant. Check out the diagram below:




You can see that a lot must still be done for renewable energies to expand and slowly replace the fossil fuel resources. Most of the renewable energy power plants, with the exception of hydro power plants, comes from SPPs. They generally deal with biomass energy. This means that they burn rice hulls, palm oil and sugarcane byproducts in order to generate steam to turn turbines. However, they also have a solar farm with the capacity of 55MW in the central region of Thailand. The hydroelectric power plants are mostly run by EGAT themselves.

To get this generated electricity from the power plant to the 220V (50Hz) socket, transmission lines are needed. In Thailand, the frequency of these transmission lines ranges from 69kV to 500kV, depending on the distance of the transmission. For longer distances and larger amounts of energy, the 230kV and 500kV lines are used. The higher the frequency, the fewer the energy loss.

In May 2013, there was a transmission problem and 14 southern provinces experienced a blackout for two hours in the evening. I know what you are thinking: “Two hours is not that much.” Unfortunately it is, especially when hospitals and factories need the electricity. Or when you have soap in your hair late at night and the water pump isn’t working. The problem was caused by an imbalance between reactive and active power in the 230kV transmission lines. For all the non-nerds out there, there was a problem with the flow of electricity in the transmission lines. This has forced EGAT and its partners to propose an upgrade of the transmission lines from 230kV to 500kV, among other things, in the south of Thailand. This can be seen in the following map:


In conclusion, the electrical generation and distribution in Thailand is pretty interesting and exciting, especially the potential for growth in the renewable energies sector. However, a lot more needs to be done, for example transmission line upgrades and, eventually, underground lying of the cables. Only time will tell how Thailand will manage the challenges ahead.

Don’t go just yet! As a bonus, I have added a diagram showing the daily load curve in different seasons. Now you will be able to see when Thais use their electricity the most.


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