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DESIGN OF A MICRO-HYDRO-POWER PLANT IN SISIMIUT

GREENLAND

Author: Konstantinos Beleniotis, Studying MSc in Engineering in Sustainable Energy.

Supervisor: Associate Professor Morten Holtegaard Nielsen

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Abstract

This investigation was done with the goal of obtaining the knowledge of how to design and build a micro-

hydro-power plant. The report took place in Sisimiut, Greenland and gave an insight of the conditions of the

area concerning the implementation of a sustainable energy technology such as Micro-Hydro Systems

(MHS) to the Greenlandic environment and community. An MHS was built in that area after the search of

suitable sites. The river at the chosen area had an average flow rate of 4.479 L/s and a measured head of

8.16m. The system had total head losses of 2.339m a 28.66% loss of head. The measured power produced

was meant to and the losses of the system were big, the result was that an MHS is a feasible solution for

the remote areas of Greenland, with the condition of finding ways to eliminate the different losses as in the

big hydro power plants working in Greenland, but without eventually losing the mobility and versatility that

differentiated MHS in the first place.

Keywords: Greenland, Sisimiut, Hydropower, Micro Hydro Power, MHS.

1. Introduction

The morphology of Greenland resulted in the absence of a central interconnected power grid. This and the

relative energy isolation from other countries has led to a decentralized/regional power system. An

inexpensive, reliable and environmentally friendly way of obtaining energy in remote areas is the use of

local hydropower sites. Hydropower is a mature technology where the energy in the water is used to turn a

wheel connected to an alternator that transforms the mechanical energy into electricity.

The aim of this field work was to investigate the feasibility of installing micro-hydro power plants in Greenland, in order to provide electricity to remote areas of the region. For that goal, a micro hydro plant was designed and assembled. A Turgo, micro- MHG-500HH ([6] Appendix A) was used to that end. The project involved:

Investigation of suitable locations and installation of the system

Measurements of the energy production

Calculation of the possible losses of the system

Calculation of the total power output

Micro-Hydro is a type of hydroelectric power plant that typically produces up to 100 kW of electricity using

-of-river , or water diversion schemes (Figure 1). The investigation took place

in the area of Sisimiut (Figure 1: Greenland and the area of Sisimiut

Figure 2: A typical micro hydro power plantFigure 1) where there are several promising locations (rivers and

lakes).

Before establishing a plant, certain preliminary investigations were necessary, such as precipitation, run-off

and topography of the catchment area. The investigations further included the location of a suitable river

and lake near the town of Sisimiut, and the design of the plant i.e. pipelines, turbine, generator, water

intake.

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Figure 1: Greenland and the area of Sisimiut Figure 2: A typical micro hydro power plant

2. Methodology

2.1 Background

There are certain design parameters of a MHS (micro-hydro system) that need to be stated (Figure 3):

The head: the vertical distance between the turbine and the water source.

The flow: the amount of water that passes through the turbine at any instance.

Potential Power and Energy: The energy I the water flowing in a closed conduit of circular cross section,

Where H is the total energy, h is the elevation head, P the pressure, g the specific weight of water, V the

velocity of the water, g the gravitational acceleration and L the energy losses.

Figure 3: Design Parameters of a hydro-power system (Morten H. Nielsen lecture slides 2013)

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2.2 Suitable Location Search

In order to find a suitable location for the project certain requirements needed to be fulfilled:

A high head (vertical distance between the intake and the turbine).

A high enough flow rate of the water.

Close proximity to the town of Sisimiut and easy access.

A possible water reservoir in order to ensure a stable flow.

in the selection of the site. As shown in Figure 3 the Power output of a system is directly correlated to a

combination of these two parameters. The PowerPal system was designed for use in different locations,

with different combinations of flow and head (Table 1).

Table 1: Dependence between output power and critical factors of turbine. (PowePal manual 2008)

Turbine MHG-200HH MHG-500HH

Water head H (m)

5 6 7 8 9 10 11

Water flow Q (l/sec)

6.3 6.4 7.4 7.9 8.4 8.9 9.1

Power output (W)

160 200 275 325 390 460 520

Head measurement:

Due to the fact that resources in Greenland were limited two very simple methods were used in order to

in order to clarify if there is a minimum required distance. At the final site

chosen, a different, more accurate method was used. It consisted of using a pressure gauge at the turbine.

It measured the pressure of the water at that location in psis. Then the head was obtained by simply

dividing the pressure obtained by 1.422 psi/meter.

Water flow measurement:

For the measurement of the water flow of the potential sites, another simplified yet accurate method was

used. A 50L bucket and a timer. By dividing the amount of time taken for the river to fill a certain volume of

water in the bucket from that volume we found the flow of the river in question. This was done several

times in order to minimize the margin of error.

2.3 Losses

A big part of this investigation was the calculation of the losses of the MHS, how they were created and

how they could be avoided. Water loses energy as it flows through a pipe due to:

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Loss of head due to friction

Loss of head due to turbulence

Trash rack (or screen) losses

Loss of head for sudden contraction or expansion (Figure 4)

Loss of head in bends (Figure 4)

Figure 4 The influence of bending ratio Contraction/expansion lead to loss of head

number (Re), which is defined as:

Where v is the kinematic viscosity of the water which changes with its temperature. It is a dimensionless quantity that is used to characterize different flow regimes like laminar or turbulent flows (wiki). For the turbulent flow, the moody chart will be used in order to find the Darcy friction factor (fD)[7]. The Moody chart or Moody diagram (Figure 5) is a graph in non-dimensional form that relates the Darcy-Weisbach friction factor, Reynolds number and relative roughness for fully developed flow in a circular pipe. It can be used for working out pressure drop or flow rate down such a pipe.

Figure 5: Moody diagram

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2.4 System installation

After the suitable river and location were found the installation of the turbine began in accordance to the

guidance of the PowerPal installation manual (Appendix A). The site was first prepared in order to

cks

of the river bed were moved in order to allow the decent of the penstock in a straight line. The system was

installed as in (Figure 6)[6]

Figure 6: System Installation

The penstock was installed as straight as possible and several PVC pipe segments were used

The electrical wiring was done afterwards. First the turbine was grounded by attaching a cable to it

and a metal rod stuck in the ground nearby. I order to regulate the output voltage of the turbine

since it was depended of its rotational speed which varied, and electronic load controller (ELC) was

introduced to the system (Figures 7 & 8). The ELC was used to increase the power consumption

with a dummy load, automatically whenever the output voltage was above the desired value of

200V. The turbine would then be connected to a load (light lamp) that was connected with the

purpose of measuring the power output, and an AC to DC battery charger connected to a car

battery, in order to investigate the possibility of storing any surplus electricity produced.

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Figure 7: Connection of the ELC

Figure 8: The ELC and a heating element

3. Results

3.1 Choosing the suitable location

Two locations near the town of Sisimiut where found to be suitable for the MHS. Sites A and B can

be seen in (Figure 9).

Figure 9: Map of Sisimiut with the two sites

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The heads and flow rates of the two sites were found and compared in order to find the best one

suitable for the project. The heat for site A was measured by the gps to be between 7-9 meters

while the head for site B was close to 11 meters, which is the maximum value that the PowerPal

turbine can take before having an increased voltage output. The different flow rates were

measured with the method stated above and can be seen in (Tables 2 & 3)

Table 2: Flow rate measurement of site A Table 3: Flow rate measurement of site B

Litres seconds flow (l/s)

Average flow(l/s)

40 9.1 4.40 3.78

21 6.3 3.33

20 5.7 3.51

25 7.1 3.52

21 5.6 3.75

20 5.2 3.85

24 5.4 4.44

15 4.1 3.66

20 5.6 3.57

20.5 5.4 3.80

Although site B had the highest flow rate and head, it was more difficult in terms of logistics. It

could only be reached by sea or the turbine and the rest of the equipment had to be carried for

many kilometers of hiking and the waterfall was steep not allowing for major site preparation such

as dam building. This with the combination of the ideal place of site A near the road and its ease of

environmental intervention, led to the decision of using site A for the investigation.

3.2 Head losses calculation

All the necessary measurements of the system were taken and can be seen in (Tables 4)

Average flow pipe lenght (m) intake diameter (m)

pipe diameter (m)

pressure (bars)

4.48 21.6 0.076 0.07 0.8

Table 4: System measurements at site A

litres seconds flow (l/s)

30 7.2 4.16

20 5.1 3.92

19 4.5 4.22

19 3.6 5.27

litres seconds flow (l/s)

Average flow(l/s)

21 5 4.20 4.76

19 5.5 3.45

20 7 2.86

27 6 4.50

20 5 4.00

25 4 6.25

22 4 5.50

25 4 6.25

20 4 5.00

25 4.5 5.56

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20.5 5 4.10

20 3.3 6.06

19 4 4.75

20 4.6 4.34

20 4.1 4.87

18 5.8 3.10

To measure accurately the head of the MHS the pressure at the end of the penstock was

measured (P=0.8bars=11.60304 psi. But we know from (manual) that pressure of 1.422 psi

corresponds to a 1m head, thus the current head of the MHS site was 8.16m. The water velocity is

calculated by ( ), where Q is the flow rate and A the cross section pipe area. It is found then

that

(m/s).

The kinematics viscosity for 10oC is 1.307*10-6 with that the Reynolds number could be found:

Re=15579.954. This is a number bigger than 4000 which indicates a turbulent flow. The relative

roughness was calculated as /D=4.28*10-5, with the coefficient of average roughness for our

material being =0.003 (ESHA).Since there is a turbulent flow in our system and the friction factor

could be found more easily with the use of the Moody diagram to be fD=0.023. Finally with the use

of the DarcyWeisbach equation

[7]

The head loss due to friction was found to be 0.031m. In addition to the loss due to friction, there

were more losses as previously stated:

Loss of head due to turbulence

Trash rack (or screen) losses

Loss of head for sudden contraction or expansion

Loss of head in bends

All of these losses were present in this investigation as it can be seen from the photos of Appendix

B. Their calculation though due to the conditions of the experiment were very difficult to take

place. The total sum of the uncalculated head losses though, could be found as the difference

between the theoretical expected power output and the measured one at part 3.3

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3.3 Frequency and Power Output of the generator

Power Output

Next the frequency and power output of the generator were calculated. The theoretical power

output was given by

P=g*Q*Htot=9.81*4.48*10-3*(8.16-0.023) =359.063 W

In order to measure the experimental power output the electric circuit of the methodology part

another method

needed to be found. In the end only a heating element was connected to the turbine as load, since

it could withstand the changes in voltage. Without the ELC though the AC battery charger and the

car battery could not be implemented into the system. With this configuration the measurements

taken gave the date shown in (Table 5)

Table 5: Voltage and Current measurements of the system

Current (A) 1.49

Voltage(V) 69

This means though that the measured power output was 1.49*69=102.81 W. The difference

between the theoretical and experimental values can be translated as the additional losses of the

system which are found to be Htot =2.339m, which translates into 28.66% of the total head.

Frequency

calculated with the use of this equation:

[7]

Where H is the net head after the losses, D the diameter and p the number of pole pairs.

This gives us a result of 89.984 Hz which is a 50% increase from the nominal value of 60 Hz.

4. Discussion/Conclusions

The expected finding of this investigation was the modelling of a feasible micro hydropower plant, which

would be ideal for the support of remote areas of Greenland (settlements tourist/hunting cabins) that were

not connected to the electricity grid. Two different sites in the close proximity of the town of Sisimiut were

investigated. The system proved to be easy to install and move to other locations, as it only takes a few

days to fully set it up and get it running. The results of the measurements though were not as encouraging

as expected.

The total system losses were 28.9% of the total head, and resulted in a decreased power production by

50% than the theoretical value. This was done mostly because of the unresolved installation issues. The

Pipe although it is flexible and contributes to the mobility of the system, is also one of the main reasons for

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the head losses. The bending, expanding and collapsing of the penstock was a constant problem that could

be fixed only by a small percentage. The frequency of the generator was also found to be a lot higher than

the allowed limit of 60Hz with a calculated value of almost 90 Hz. This probably happened because of the

bending of the pipe which increased the velocity of the water and the turning rate of the turbine. Also the

absence of an electronic controller and different loads may also be a reason for this.

The amount of intervention allowed to be done to the environment is also an issue since the best

conditions for the installation of a hydro plan require the creation of small dams and maybe even the

diversion of the river. Even though the difficulties that the project faced, gave lower results than expected,

overall the idea of the use of MHP was proven doable. The system still produced 102W of electricity and

with better planning, installation and equipment, it could get really close to its nominal power output. The

use of car batteries for energy storage seems to be the most feasible option for systems like the one

ld that MHP could be the

solution for providing electricity to remote isolated areas, with the implementation of those experiences

References [1] Celso Penche, a small hydro site, European

Small Hydropower Association, European Commision 1998.

[2] Morten Holdegaard Nielsen, University lecture, Energy in the Arctic, 2013

[3] CLEAN ENERGY PROJECT ANALYSIS: RETSCREEN ENGINEERING & CASES TEXTBOOK. Ministry of Natural

Resources Canada 2001-2004, ISBN:0-662-35671-3 Catalogue no.:M39-98/2003E-PDF.

[4]Prof, J-L KUENY, Objectives for small hydro technology, INSTITUT NATIONAL POLYTECHNIQUE DE

GRENOBLE

[5]Brian B. Yanity, Cold Climate Problems of a Micro-Hydroelectric Development on Crow Creek, Alaska,

Institute of the North. Anchorage Alaska, 2007

[6]Asian Phoenix Resources Ltd., Canada, Use and Care Instructions for a new PowerPal, High head Micro-

Hydroelectric Generator, 2008

[7]European Small Hydropower Association. ESHA, Guide on How to develop a Small Hydropower Plant,

2004

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APPENDIX A

TECHNICAL

SPECIFICATIONS

MHG-200Hh MHG-500HH

1 Rated power output 200W 500W

2 Maximum allowable

load

250W 650W

3 Intended voltage 110 / 220V~ 110 / 220V~

4 Frequency at rated

power output

50-60 Hz 50-60 Hz

5 Frequency at

runaway speed

70 Hz 70 Hz

6 Rotor runaway speed 1400rpm 1400rpm

7 Weight 34kg 36kg

8 Turbine runner type Turgo Turgo

9 Runner diameter 180mm 180mm

10 Number of buckets 20 20

11 Bucket diameter 68mm 68mm

12 Number of nozzles 1 1

13 Jet diameter 28.5mm 28.5mm

14 Generator Single phase

permanent magnet

alternator

Single phase

permanent magnet

alternator

15 Rotor characteristics NdFeB 3-pair pole

permanent magnet

NdFeB 3-pair pole

permanent magnet

16 Stator wire size 0.5mm 0.7mm

17 Upper bearing size SKF6301-2Z SKF6301-2Z

18 Lower bearing size 6204 6204

19 Seal size 17x40x7mm 20x47x7mm

20 Recommended cable 0.75 sq.mm/A 0.75 sq.mm/A

21 Operating

temperature

5 to 50 C 5 to 50 C

22 Operating humidity 0 to 90% 0 to 90%

SYSTEM INSTALLATION

After locating a suitable site and completing the earthworks (if any), your PowerPal is ready for

installation. To do this:

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1. Bolt the turbine to a turbine stand or base which allows at least 100mm clearance between the turbine

and the ground. The turbine stand should be sturdy and made from concrete or steel as shown on page 4

of this manual. Bolt spacing is 210mm as shown in the diagram.

2. Bolt the turbine to the penstock adaptor flange (A see below). The optimal diameter of the penstock

and PVC fittings is 110mm, to produce the most power. The minimum diameter is 76mm but less power

output may be expected.

3. Turn the handle of the spear valve anticlockwise until the valve is fully open.

Always turn the handle slowly and smoothly.

4. Affix a 135 (or other) elbow bend of PVC into the forebay wall. This should be fitted with an

atmospheric vent (hollow bent pipe), which allows air to escape from the penstock. The upper opening

of the atmospheric vent should be higher than the water level in the forebay. Divert water away from the

forebay or else block the top of the penstock pipe during the installation procedure.

5. Start installing the penstock. Assembly can begin from either direction but it is usually easier to begin

uphill the turbine is much easier to move around than the forebay is. The penstock should be well

secured i.e. supported or buried at regular intervals to support its weight when full this is particularly

important at the bottom of the penstock so that PowerPal cannot be knocked over. At least two people

should handle the penstock, one uphill and one downhill, until it is fitted into both the elbow bend and

the penstock adaptor flange (B). If PVC is used for the penstock then use PVC glue to bind the joints

but note that the PVC must be dry for the glue to work.

6. Once the glue is set the turbine can be started. Fill the forebay and allow the water to flow freely into

the penstock. The turbine runner will rotate and spent water will flow out in front of the turbine stand

(into an escape drain). An alternative is to allow the water to escape through the floor of a purpose-built

platform. Once the water is flowing freely the electrical setup may begin.

7. Earth-bond (ground) PowerPal. Do this by attaching one end of a suitable length of 0.75 sq.mm/A

wire to PowerPal and the other end to a metal object or metal stake in the ground nearby PowerPal.

Although the risk of electric shock is already low, this earth-bonding is still best practice.

8. Run the required length of two-strand, jacketed electrical cable from PowerPal to your house etc. Use

3.75 Ampere wire (0.75 sq. mm / Amp) for both MHG-200 and MHG-500 models. This is thicker than

is required but thinner wires are more fragile. Attach the electrical cable to the red and black connecting

points on the PowerPal generator.

Do not allow electrical contacts to become wet. Use dry hands. Beware of electrocution. 9. Install the electronic load controller (ELC) in a dry place inside the house (or next to the generator)

10. Place the dummy load (immersion heater) attached to the white cable into a water tank of minimum

volume 50 litres. The tank should be made of non-conductive material and the dummy load should be

fully immersed. The ELC is always positioned between the generator and any circuit breaker. Check all

the connections again.

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11. Observe the meter to check the operational state of the ELC - is the voltage at 220V or 110V

(depending on your country) when the water is let into the turbine? If the voltage still increases, then

stop and check the connections, and the voltmeter. Adjust the potentiometer on the circuit board (as in

photograph) slowly until the voltmeter reads 220V or 110V.

12. You can now plug lights and appliances directly into the ELC ready for use, with or without

additional house wiring or a circuit breaker. The voltage needs only to be checked and adjusted if the

water flow rate changes. Heavy rain may increase the flow rate, or a prolonged dry period may

gradually reduce it. Check the voltmeter from time to time and adjust the ELC if necessary.

APPENDIX B

Photograph 1: Site B notice the not easily accessible waterfall

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Photograp 2: Site A before the connection of the MHS

Photograp 3 Photo left The intake with the thrash rack. Photo right. Notice the collapse in the middle of the penstock.