DESIGN OF A MICRO-HYDRO-POWER PLANT IN SISIMIUT.pdf
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Transcript of DESIGN OF A MICRO-HYDRO-POWER PLANT IN SISIMIUT.pdf
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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.