Micro Hydro

SURVEY OF MICRO-HYDRO POTENTIAL IN SARAWAK

INTRODUCTION

There are great potentials for micro-hydro power in Sarawak, especially for the many scattered communities who have no access to the power grid.
The vast networks of rivers and streams found in the rugged terrains amongst the scattered rural population within the vast land area of provide great potentials for this kind of sustainable renewable energy.

MAPPING AREAS

A total of 104 sites/settlements in 8 divisions throughout the state of Sarawak as per Figure below was visited and surveyed in this mapping works, namely;

  • Samarahan Division
  • Sri Aman Division
  • Betong Division
  • Sarikei Division
  • Kapit Division
  • Bintulu Division
  • Miri Division
  • Limbang Division

 

Figure: The State of Sarawak


Each of these 8 divisions actually have its sources of water tributaries from the mountain ranges that stretch from the South to the North of Sarawak that flows into the main rivers in the state as follows:


Figure: Sarawak’s terrain


The rural population is scattered either along the river upstream or in the highlands which are far off from the power grid. These areas are accessible either by boats or travelling through logging roads. Almost all settlements are located either near to or along the rivers or streams. The distances of the potential source of hydro power ranges from less than a kilometre to almost 5 kilometres. At present most of these settlements are using small generator sets as source of power for their electricity.

 

TECHNICAL APPROACH

The technical approach to this survey/mapping was to collect data as well as to record the locations of the settlements, their potential sources and calculate the power producing potential of every source within each of the settlement. No other feasibility assessments were done. The minimum and maximum water levels in all streams/rivers were based on the information or experiences from local dwellers/settlers. This also includes the adverse dry weather conditions during the period of May to October 2009.

Locations of settlements are identified by use of Geographic Information System equipment, the portable handheld Global Positioning System (GPS) unit. It determines the latitude and longitude of the locations. The GPS unit is also used in trekking the routes of each source from the settlements by giving its estimated distances and in determining the estimated hydraulic head of the source.

The calculation of power potential of the streams/rivers requires two values: the flow rate and the hydraulic head corresponding to the elevation difference between the upstream and the downstream ends of the reach. The flow rate was calculated based on the average speed across the stream/river and its average cross sectional area. The power potential values are gross power values based on the estimated flow rates obtained during the day of survey.

 The subsections that follow describe the details of the various aspects of the technical approach in the calculation of the power potential and data analysis in producing the mapping.

 

THEORY

The calculation of the stream flow rate, hydraulic head and subsequently, power potential is based on the data and information being collected on the ground during the day of survey. That could mean that the water flow at that time could either be between the minimum and maximum range of flow.

Flow Rate Calculations


The flow rate was calculated using the average cross sectional area of the stream and the average velocity across that cross sectional area of stream. The velocity of stream was taken using s stream flow meter. The flow meter consists of an impeller which rotates and a counter will count the number of impeller revolutions per minute.

The flow speed is given by the following formula;


V = 0.000854 C + 0.05

Where
V = velocity in metres/second
C = counts per minute (impeller rotations/minute)
The estimated flow rate is calculated using the equation;
Q = A x V
Where
Q = estimated flow rate in cubic metres/second
A = average cross sectional area of stream in square metre
V = average velocity of stream in metre/second

 

 

 

POWER POTENTIAL CALCULATION

The power potential of a stream was calculated using the hydraulic head and the estimated flow rate. The hydraulic head associated with each stream was obtained using elevation data from the handheld GPS unit. It provides the elevation data at the upstream and the downstream ends of reach. The difference of these elevation values was the hydraulic head for the flow.
 

The following equation was used to calculate the power potential;


P = g x Q x H


Where
P = Power in kilowatts
g = accelaration due to gravity, 9.81 metre/second2
Q = estimated flow rate in cubic metres/second
H = hydraulic head in metre


DATA

All data collected are in both hardcopy and also stored in the GPS memory. These data will be logged into a spatial database management system with the assistance of the GIS section. The data are then transformed into a mapping data which will show the locations of the micro hydro resources and potential.


SITES SURVEYED & DATA ANALYSED

The following are the settlements that have been surveyed for potential micro hydro

Power sources;

NOS.

DIVISION / SETTLEMENT

WATER SOURCE

HEAD (m)


POTENTIAL POWER (kW)

 

Samarahan

 

1

Kpg. Mugah, Simunjan

Sg. Mugah

18

1.8

Sri Aman

 

 

 

 

1

Rumah Augusti

Batu Ninding
Sg Tembawai

35
38

12
24

2

Rumah Alo

Sg. Isu
Wong Selandak

7
20

5
5

3

Rumah Reggie

Sg Tembawai

38

24

4

Rumah Jimba

Wong Sengkadan

20

7

5

Rumah Anam

Wong Sebidai

18

6

6

Rumah Alam

Wong Kera

5

7

7

Rumah Kili

Wong Keranggas

35

27

8

Rumah Edward

Wong Kepayang

30

59

9

Rumah Kino

Sg. Sumpa

40

16

10

Rumah Ngumbang

Sg. Sumpa

12

55

 

 

Total Potential Power

247

Betong

 

1

Rumah Betti

Sg Ikit

35

7

2

Rumah Aka

Sg Tapeh Mit

30

25

3

Rumah Akat

Sg Jepilai

40

8

4

Rumah Meruda

Sg Penyuin

50

34

5

Rumah Dau/Temedak

Sg. Mawang

33

10

6

Rumah Melina/Luing

Sg. Sepak

15

95

7

Rumah
Empaling/Jelang

Sg. Sepak

52

15

 

 

Total Potential Power

194

 

Sarikei

 

1

Rumah Gerasi

Wong Jungin
Wong Nyamok

16
10

111

2

Rumah Achi

Wong Belaidan

5

3

3

Rumah Japar

Wong Kandis

64

904

4

Rumah lau

Wong
Kuji

49

258

5

Rumah Anyut

Wong Stapang

5

38

6

Rumah Uli

Wong Kebok

7

4

7

Rumah Kapor

Wong Sawa Bua

17

28

8

Rumah Mamat

Wong
Splak

7

4

9

Rumah Changan

Wong Sechelap

52

9

10

Rumah Nalong

Wong Bekiok

7

36

11

Rumah Uding/Muling

Sg. Sepasir

21

17

12

Rumah Morris

Sg. Sembawang

15

15

 

 

Total Potential Power

1427

Kapit

 

 

1

Uma Apan

Sg Bevan

19

9

2

Punan Bah

Sg O’ong

50

270

3

Uma Seping Lama

Sg Semabu

25

8

4

Uma Seping

Sg Pekasi

50

130

5

Uma Seping Baru

Sg Braan

23

38

6

Uma Sambop

Sg Jemulai

63

76

7

Uma Kenyah Long

Sg Sarikei

37

37

8

Uma Long Bangan

Sg Seregat

30

81

9

Uma Badeng

Sg Dungan

80

136

10

Uma Kulit

Sg Semuang

35

32

11

Uma Aging

Sg Kejabo

49

63

12

Uma Sekapan Panjang

Sg Dungan

80

136

13

Uma Tevok

Sg Belenyu

23

9

14

Uma Tanjong

Sg Pawah

33

59

15

Uma Punan Tepalaing

Sg Muing

40

33

16

Punan Biau B

Sg Pelaran

33

7

17

Punan Biau A

Sg Siap

34

12

18

Uma Semanok

Sg Jelutong Barit

25

6

19

Uma Sekapan Piet

Sg Tap

53

117

20

Uma Kejaman Neh

Sg Sebatu

56

25

21

Uma Kahei

Sg Mekero Span

29

6

22

Uma Lahanan

Sg Semuang

81

29

23

Uma Kejaman

Sg Luyoh Maau

43

15

24

Uma Nyaving

Sg Maau

23

12

25

Rh Ribut

Sg. Rapuh

70

14

26

Rh Layang

Sg. Sepetai

20

8

27

Rh. Juntam

Sg. Elik

43

13

28

Rh Bigau

Sg. Serukuh

10

1.5

29

Rh. Manggan

Sg. Belinyuk

40

16

30

Rh. Mejang

Sg. Nyumbuh

50

22

31

Rh. Ghani

Sg. Sesebau

43

9

32

Rh. Danial Dian

Sg. Apan

48

19

33

Rh. Rambor

Sg. Sepayang

27

3

34

Rh. Gelimai

Sg. Keli

14

12

35

Rh. Jembu

Sg. Sembawang

43

4

36

Rh. Jamba

Sg. Selikang

27

8

37

Rh. Lugat

Sg. Sebabai

48

14

38

Rh. Ngiang

Sg. Sebabai

48

14

39

Rh. Undi

Sg. Pelak

20

3

40

Rh. George

Sg. Lulut

53

43

41

Rh. Sadang

Sg. Keranggan

14

10

42

Rh. Beraoh

Sg. Serambi

26

7

43

Rh. Tang Ak. Jabit

Sg. Sepinang

23

6

44

Rh. Kilau

Sg. Sagan

46

115

45

Rh. Jala

Sg. Sepayang

24

22

46

Rh. Salang

Sg. Sibau

47

57

47

Rh. Anding

Sg. Sepunan

34

100

48

Rh. Tang

Sg. Sebuluh

32

156

49

Rh. Anchi

Sg. Sebuno

17

22

50

Rh. Jos

Sg. Liang Mansai

34

36

51

Rh. Barang

Sg. Pan

66

104

52

Rh. Tinggom

Sg. Liang Mansai

34

36

53

Rh. Nyawai

Sg. Sepulau

24

106

54

Rh. Gesang

Sg. Sepulau

24

106

 

 

Total Potential Power

2432.5

Bintulu

 

1

Data Kakus

Sg Nyuvet

70

171

2

Rumah Julaihi Keti

 Sg Tuan

18

16

3

Rumah Dinggai

Sg Epoh

65

10

4

Rumah Sabang

Sg Separai

100

745

5

Rumah Entri

Sg Pusang

20

4

 

 

Total Potential Power

946

Miri

 

1

Long San

Sg. San

40

110

2

Lio Matu

Sg. Te'baan

49

201

3

Long Semiang

Sg. Semiang

77

113

 

 

Total Potential Power

424

Limbang

 

1

Long Tuyo

Pa’ Tuyo

50

1363

2

Punang Berayong

Pa’ Buyot

46

288

3

Punang Trusan

Pa’ Langar

100

390

4

Long Telingan

Pa’ Langar

100

390

5

Pa Berunut

Pa’ Gituan

25

55

6

Long Tanid

Pa' Lebaluh

55

215

7

Buduk Nur

Pa' Kumap

134

661

8

Long Ritan

Pa' Ritan

50

83

9

Long Beluyu

Pa' Beluyu

29

742

10

Long Kerebangan

Pa' Kerebangan

197

23

11

Long Semadoh

Pa' Sugih

476

226

12

Long Sukang

Pa' Silo

37

50

 

 

Total Potential Power

4486