Micro- and pico-hydropower in Thailand: a short overview of technology, applications and critical factors for success Chris Greacen Palang Thai www.palangthai.org Slides for the Energy for Environment Foundation Annual Seminar “Protecting the earth through green energy” 15 November, 2007 Pullman Kingpower Hotel, Bangkok

Micro-hydro technology

Micro-hydro technology Micro-hydropower harnesses energy from falling water. Typcially some water is diverted from a stream using a weir. Water is then transported by a channel or pipes to a powerhouse downstream where the pressurized water spins a turbine, generating electricity. Source: Inversin, A. R. (1986). Micro-Hydropower Sourcebook.

Micro-hydro technology Centrifugal pump Pelton Turgo Crossflow Kaplan There are many different types of turbines, and their use depends on the height drop and flow at the site. For small projects, it is also possible to use a centrifugal pump running backwards. Installed cost is roughly baht 30,000 to 100,000 per kW.

Micro-hydro examples

Micro-hydropower is suitable for both grid-connected and off-grid electricity. This 40 kW installation in Mae Kam Pong village in Chiang Mai province is producing electricity that is providing electricity to the Provincial Electricity Authority (PEA). Eventually revenues from electricity sales will go to the village micro-hydropower cooperative. The project produces about 400,000 baht per year worth of electricity.

This installation in Mae Kam Pong is not connected to the national grid. It provides electricity directly to about 190 village households. This installation is one of 60 built as a joint project between villagers and the DEDE. 2 @ 20 kW (one pelton, one crossflow) Weir: 2 meters high, 15 meters wide Headrace: 300 mm concrete, 470 meters long Penstock: 300 mm steel, 100 meters long Head: 55 meters Max flow: 120 liters/sec Distribution system: 12 km Transmission voltage: 3.5 kV 190 households 3.99 million baht. Finished in year 2526 (1983). 99,725 baht per kW

This is a much smaller installation – a 3 kW installation that uses a centrifugal pump running backwards as a turbine. The installation is at Huai Kra Thing village, Mae Ramat Amphur, in Tak Province. The pump’s motor is run backwards as a generator. This kind of installation requires some custom electronics, but works quite well. An advantage is that repairs to pumps are easy – Thai mechanics are familiar with pumps. Huai Krating, Tak Province, Thailand Power: 3 kW Head: 35 meter Flow: 20 liters/second

This is an even smaller installation – generating about 1 kW for a school, clinic, and community center in Kre Khi village, Tha Song Yang amphur, Tak Province. It uses a Chinese turgo, which is available for about 10,000 baht. It uses about 15 liters/second of water, and has a head of about 10 meters.

This tiny installation generates 200 watts, and powers lights in a youth training center in Baan Klang Luang village, Doi Inthanon, Chiang Mai. The turbine, purchased from Vietnam, cost 4,000 baht. It is powered by water falling about 1.7 meters. 3000 baht in Vietnam 2000 baht in Laos 200 watt

Micro-hydro crucial success factors

Micro-hydro -- crucial success factors Micro-hydropower requires small streams, in general, the steeper the better. Care has to be taken that using water for micro-hyropower leaves plenty of water in the stream section for nature. Projects we do take less than half the dry-season flow. Also important that it doesn’t take water away from agriculture. These conditions are generally not hard to meet. Getting access to water may be difficult for bigger projects, but for small village projects is generally not a problem – since villagers are using the water anyway. Knowledge about how to do micro-hydro is probably the biggest missing factor. There is a big need for practical education on micro-hydropower and pico-hydropower. Government (DEDE) does one or two projects every year. BGET does one or two pico-hydropower projects a year. Besides that, there is very little.