The main power supply of Laos.

In 1997 I returned to Vientiane from Luang Prabang. These two cities and others Laos' and a few Thailand's cities are supplied by the electric power from one source, Nam Ngum dam.
from http://www.mekong.es.usyd.edu.au/case_studies/nam_ngum/nam_ngum_dam.htm

Nam Ngum Dam was the LPDR’s first hydro dam. It was financed with assistance from ten countries, under the auspices of the United Nations. It was constructed by a Japanese firm and was completed in 1971. The dam has a generating capacity of 150 megawatts.

Nam Ngum Dam generates most of Laos' electricity, including all the power used in the capital, Vientiane. Even more important is the 70 to 80 per cent of electricity that is exported to Thailand, accounting for about a quarter of Laos' foreign exchange earnings. While bringing in significant foreign exchange earnings, Nam Ngum is economically questionable on several counts. Between 1982 and 1992, electricity generated and exported declined, a result uncorrelated to rainfall. Its revenues have not been enough to cover the cost of repairs, most of which has been covered by Japanese aid. Already apparent is the fact that its watershed will require significant ongoing financial and management input.

Nam Ngum Dam is a resource user in a number of respects. The reservoir occupies what used to be fertile land and forest, and communities affected by flooding continue to suffer direct and indirect consequences a quarter of a century later. Nam Ngum Dam thus competes for land, forest and water resources, but also bears the consequences of resource use in other parts of the watershed.

Back to Vientiane capital.

In 1997 I left Luang Prabang after 3 years experience in Transmission line and substation.
That year 1997 was a year of crisis in Southeast Asia. Before crisis 1 US$ = 700 kips and after 1US$ = 10,000 kips.
In Vientiane Prefecture (lately Vientiane Capital) I worked as a drawing draft man for ECI, one of many branches of Electricite du Laos. ECI does the electrical installation and construction work. I prepared drawings for many projects such as Vientiane street lighting project, Second Vientiane Electrical network Rehabilitation Project and many rural electrification projects

Lightning: the main reason for power cutoff

The northern part of Laos is mountainous.
The transmission line is across the mountainous area.
The raining season in Laos is about 6 months.
Therefore the TL is under rain and thunder for haft year each year.
The lightning can cause power cutoff but in very short time but that occurs very often

How good if we can bring electricity to people in remote area

The distance from Vang Vieng substation to Luang Prabang substation is about 250 kilometers across the mountainous area. 22 kV distribution lines could not reach all people living between these 2 substations. Most of people are from minority tribes living in sparsely populated villages.

In the Thalat-Luang Prabang transmission line besides the normal high voltage conductors, the top wire, usually used as lightning protection wire, is supplied with 25 kV power. The villages nearby the transmission line can get electricity from that overhead wire.

The electricity obtained from that wire is transformed to low voltage single phased network. It can not be used with 3 phase motors, just for lighting.

That system is unique. It can be seen only in Laos or may be in another poorest countries. We call it shield wire system.

This 25 kV shield wire system is used along Thalat-Luang Prabang transmission line only. It provides electricity to the area where conventional 22 kV lines could not meet the internal rate of return.

There is another shield wire system which supplies 34.5 kV line on doubled overhead ground wires and gives the villagers 3 phase energy to run motors. This system came after the first and is being used in the Northern Laos while the SWER system is being used in the South.


I can answer to some of your question but not all, please discuss about this. Post your comments please.