DESIGNDOCUMENT

FORSOLARPOWER

DRIVENWATER

SUPPLYSCHEMEIN

LORENKACHEW

CLUSTER

INNYANGATOM

DISTRICT

By:- Fasil Ayele

Design

Contents Executive summary ....................................................................................................................................... 2

Design Document for Solar power driven water supply scheme in Lorenkachew cluster in Nyangatom

District ........................................................................................................................................................... 3

Solar Resource .......................................................................................................................................... 3

Pump selection.......................................................................................................................................... 4

Selected Pump specification ................................................................................................................. 6

Controller Selection .................................................................................................................................. 6

CC2000 Controller ................................................................................................................................. 6

Controller Specifications ....................................................................................................................... 7

PV sizing .................................................................................................................................................... 8

Selected PV Module .............................................................................................................................. 9

Sizing Array( Array configuration) ........................................................................................................... 12

Array Mounting Method ......................................................................................................................... 13

Mounting Orientation ......................................................................................................................... 13

Mounting structure ............................................................................................................................. 14

Foundation .............................................................................................................................................. 15

Sizing Cabling .......................................................................................................................................... 15

Pipe sizing ................................................................................................................................................ 16

Water level sensors and pump controls ................................................................................................. 16

Float switch () (open on rise) .............................................................................................................. 17

Float switch (ss100 water sensor) (close on rise) ............................................................................... 17

ss100 water sensor ............................................................................................................................. 17

System Connection Diagram ................................................................................................................... 17

Grounding ............................................................................................................................................... 18

Lightening Protection .............................................................................................................................. 18

Design Revision and designed system capacity ...................................................................................... 19

Power supply circuit ............................................................................................................................ 19

Pump delivery ..................................................................................................................................... 19

Reservoir size recommendation ............................................................................................................. 20

Executive summary

The Nyanngatom territory is located in the south Omo zone, consisting a community of about

20, 000 people. The Nyangatom area is a dry and hot in the very south of the country

bordering Kenya. The area is situated at 360 m.a.s.l. The annual precipitation in the area is

estimated to be about 400mm. The communities’ livihood depends on livestock as well as

agriculture.

The district is located at 4.681N, 35.946E on the globe.

Design Document for Solar power driven

water supply scheme in Lorenkachew cluster

in Nyangatom District

Solar Resource The Nyangatom District is popular for low rain regions in Ethiopia and dry most of the time throughout the year.

Theoretically from its location on the glob, i.e 4.6810

Latitude and 35.9460E which is a region believed to be the

solar belt, it is not wrong to estimate a productive solar system.

According to the data we have collected from Homer Energy website, the solar data for the specified location

shows same

Clearness Daily Radiation

Month Index (kWh/m2/d)

January 0.645 6.136

February 0.619 6.199

March 0.6 6.244

April 0.529 5.54

May 0.549 5.526

June 0.583 5.722

July 0.56 5.503

August 0.609 6.212

September 0.619 6.405

October 0.603 6.074

November 0.63 6.038

December 0.661 6.145

Let us select Design month to be July, because that is the worst solar resource month in the location.

Water Demand for the Lorenkachew Kebele is 15,000 litres per day

Therefore with the design month insolation Peak sun hours (PSH) is 5.503 perday

With the available solar resource we can pump

���� ��� ����� � ������� =����� �� ����� � ���

PSH per day x

hr

60min

���� ��� ����� � ������� =%&'''

&.&') x

*+

,'= 45 litres per minute

Pump selection

The contracting Authority recommends SC series pumps. We also recommend using SC series pumps for the

following reasons.

1. SD series pumps need diaphragm replacement yearly

2. SC series pumps are able to pump higher volume of water

3. SC series pumps are capable of pumping from greater depth.

4. SC series pumps are best suitable for village water supply and this is a village water supply project

The pump we supply is from Kyocera

For selecting the surface pumps we need to determine Flow rate per minute and the total dynamic height

Determining total dynamic head

The total dynamic head of a water system must be considered when determining the size of pumping equipment

to be installed. It determines the various head losses that the pump must overcome.

Total dynamic head= elevation head + friction head loss + pressure head

Using the following data from the given specification to TDH calculator

Specifications

1. Pump flow rate =45 lt/min

2. Pipe diameter =1.25 inch

3. Pipe length =300m

4. Differential elevation=30m

5. Pipe material= Plastic

Computation for total dynamic head gives us

TDH=40 m

The most economical pump from the chart will be SC 100 60-45.

Selected Pump specification

Model Optimal

flow

LPM

OPTIMAL

HEAD m

POWER

watt

Pump

outlet

connection

size

Nominal

voltage for

optimal

operation

SC 100 60-45 61 45 1050 1-1/4” NPT 120

About the selected pump

The Kyocera SC Series solar pumps are high quality, Maintenance free, DC powered pumps specially

designed for water delivery in remote locations

SC 100 60-45 operate on 1000 watts of direct current and 120Vdc. The power may be supplied from a

variety of independent sources including solar modules and/ batteries.

The motors are state of Art, brushless DC, permanent magnet type constructed from marine grade bronze

and 304 stainless steel

Controller Selection

Like the contracting Authority we recommend utilization of CC2000 controller

CC2000 Controller

• The CC 2000 pump controller is designed to connect solar modules to Kyocera Solar’s SC series

submersible motors and centrifugal pumps.

• The controller provides current boosting combined with true Maximum Power Point Tracking (MPPT) of

the solar modules.

• The pump controller’s microprocessor constantly monitors the incoming solar power and boosts current

to operate the solar modules at their peak power point and maximize pump output.

• The controller is entirely self-configuring and requires no setup or adjustment by the user to ensure

proper operation.

• The CC 2000 controller will accommodate two to twelve solar modules in series. Any combination of

modules can be used as long as the total Open Circuit Voltage (VOC) does not exceed 300 Volts. Strings of

modules can be wired in parallel to maximize daily water production.

• In addition to solar modules, the controller will also operate from 24 to 144 Volt battery banks for use in a

broad range of applications.

• The controller’s unique design simplifies control and troubleshooting of pumping systems. Inputs are

provided for remote switches and Kyocera Solar’s unique water level sensor. Indicators provide

convenient information about voltages, switch and sensor status, and overload conditions.

Controller Specifications:-

PV sizing The PV sizing is based on the power requirement of the pump system and nominal voltage of the pump.

Nominal Voltage of the Pump= 120V

Power rating of the pump is =1050W

Pump manufacturer recommendation in sizing the PV

1. Depending on the size and number of solar modules, the array configuration, the array

mounting, location and time of year, the pump will produce the optimal flow for 2 to 8

hours per day. Kyocera suggests multiplying pump power watts by 1.16 to derive PV

watts required at STC.

2. Optimal performance above is based on nominal PV voltage of 120V for SC 1000 Series.

Therefore the size of our PV will be= 1.16*1050=1218W

The other important factor in sizing PV is the ambient temperature of the area. Because at PV cell output greatly

decreases with increase in module temperature. Usually cell temperatures are greater than environmental

temperature. And the NOCT (Nominal operating cell temperature) at a nominal temperature of 200c is 45

0c for the

selected product.

Selected PV Module

The selected location is in the solar belt and irradiance can be taken as 800w/m2

for ensuring maximum result.

The temperature at the peak sun hours in the location according to

M e a n d a i l y m a x i m u m t e m p e r a t u r e f o r c o n t r o l

p e r i o d ( 1 9 6 1 - 1 9 9 0 ) , i n t e r m e d i a t e p e r i o d ( 2 0 2 1 -

2 0 5 0 ) a n d f a r f u t u r e ( 2 0 7 0 - 2 0 9 9 ) d o w n s c a l e d u s i n g

H a d G M C 3 f o r c i n g a n d B 2 e m i s s i o n s c e n a r i o f o r J i n k a

s t a t i o n .

From the above graph we can understand that the average peak sun hour temperature in the area is about 27

0C.

We shall determine the cell temperature to calculate PV sizing.

Cell temperature can be determined using

We have the following parameters from the above explanations

TAir=270

C

NOCT=450

C

s=80mw/cm2

Therefore, Tcell=520C

Now using the temperature coefficient for the selected Pannel

From the datasheet of the product we can see that under Nominal cell operating conditions the output of the

module was 230W

Now for a module temperature of 520C and temperature cooefficient of -0.45%/

0c, the module output will be

Pdc,PTC = 230W[1 − 0.0045(52 − 45)] = 223 W

Sizing Array( Array configuration) The system voltage for the pump is given to be 120V for optimal operation

Therefore the number of module in one string will be,

M=120/35=3.42=3

We have selected 3 modules in a string because the normal operating voltage of the pump is between 30-120V

The power output from a string is p=V x I=105 x 6.4=672W

It is calculated Above that the PV should supply the load a total power of 1218w

Therefore we are expected to have n strings

N=1218/672=1.8125=2

For system voltage similarly using the temperature coefficient

Vdc,PTC = 36.1V[1 − 0.0051(52 − 45)] = 35V

The total system therefor will have two strings each having three modules. Therefore we need 6 modules of the

specified type for the project.

Array Mounting Method We can adopt two kinds of array mounting configuration Fixed mounting and tracking mount. The tracking mount

is a mounting arrangement that provides us the best solar resource utilization. However, we will adopt Fixed

mounted arrangement for this project for the following reasons

1. The place is a very remote place and installation that does not require frequent maintenance is a wise

choice

2. The location is under the sun belt so fixed arrangement of mounting still gives a good performance

Mounting Orientation

The mounting structure will be oriented to the south at 4.68 degree tilted.

Mounting structure

Frame structure

The frame structure for locating the PV modules is constructed from L-profile and T-profile 20x20x2mm steel

profile.

All joints are made of High carbon welding

Stand structure

The stand structure is made of 30x30x2.5mm RHS steel.

Foundation

On the location where the stand is to be installed we should avoid growth of any vegetation as it may result in

shading effects later when grown.

Therefore, the Area which is 6.5m x 9.5 m will be cleared excavated to a depth of 60cm. selects compacting will be

made to the bottom 20cm height and the remaining will be filled with C-25 concrete.

Anchors to mounting the stand structure will be buried under the concrete.

Sizing Cabling

The proper sizing of an electrical (load bearing) cable is important to ensure that the cable can:

• Operate continuously under full load without being damaged

• Withstand the worst short circuits currents flowing through the cable

• Provide the load with a suitable voltage (and avoid excessive voltage drops)

• (optional) Ensure operation of protective devices during an earth fault

The following data must be known for selecting cable size for DC systems

1 - Percentage cable loss acceptable: - Up to 2% loss can be tolerable to make the cabling cost reasonable for the

specified project

2 - System voltage: - our maximum system voltage is 120Vdc

3 – Maximum current (amps) to be carried by the cable =12A

4 - Length of cable run required 100m.

Using these data we can select a cable size using appropriate standards.

Accordingly, the cable size will be 25mm2

Yet the controller input for solar and pump shows that the maximum cable diameter is 16mm2 so we will select

16mm2. This in turn results the drop in the cable to about 3%.

The cable type we have selected is 2*16mm2 PVC insulated PVC sheath power cable Pure Copper

Conductor

Pipe sizing The piping between the pump and reservoir is selected to be 1-1/4”NPT plastic pipe.

Because the selected pump outlet connection size is same.

Material 1. PVC

2. Cotton Polyester Yarns

3. Calcarea

4. Oil

Grade (Quality ) Excellent Techniques & Super Quality & Standard Quality

Working Pressure

2 bar, 3 bar, 4 bar, 5 bar, 6 bar, 7 bar and 8 bar. (1bar = 14.5 psi )

Size

1.25 inch

Features

1. Light weight, good flexibility, bright color, smooth layer. Hongfei hose.

2. Roll flat and easy for take back, convenient for moving and none limit of length..

Hongfei hose.

3. It is capable of keeping the flexibility and elasticity in the low-temperature water.

Hongfei hose.

4. It is Anti-high pressure, corrosion resistance and ageing resistance. Hongfei hose.

Water level sensors and pump controls The water level sensor control of pump operation depending water levels. Adopting these sensors in to the system helps:

1. To avoid dry running of the pump in cases of low water level of the river 2. To avoid over flowing of water when the reservoir is full.

For both operations we select to use SS100 water level sensor. However the mode of operation for the above two functions is different.

Float switch () (open on rise)

This sensor is used in the reservoir or water tank. The principle of operation is that the water level gets

higher and the reservoir is almost full, the float switch gets higher and it open circuit. Therefore the

pump stops pumping.

Float switch (ss100 water sensor) (close on rise)

This sensor is used in the river or water well. The principle of operation is that the water level low and

the well or river is almost empty or too low for pumping, the float switch gets lower and it opens circuit.

Therefore the pump stops pumping. And when the water level rises the switch closes and the pump

starts to pump.

ss100 water sensor

Installed near the pump to protect the pump from dry running

System Connection Diagram

Off position

On position

Pipe

Float switch to controller

Float switch to controller

CC2000

PV Array

Float switches

Open Rise

Op

SS100

SC 100 60-45

Grounding

It is wise to ground /earth Electrical system for giving fault current an alternative path to flow through.

Pure copper grounding bar will be installed and every metallic body of the system will be grounded.

Lightening Protection

As an expensive set of Equipment in the project we should design it a lightening protection system.

Design Revision and designed system capacity

Power supply circuit

Pump delivery

The pump optimal flow rate is 61 litres / minute

With the practical irradiance of 800w/m2 the design month peak sun hours will be 4hrs. Therefore the

pump can supply

Supply of water (Litre per day) = 61Lpm x 4hrs/day x 60m/hr=14640 Litre per day.

In the worst scenario our pump can supply 14,640 Litres per day.

However, the location average practical peak sun hours is 5 (5.93 at 1000w/m2 irradiance)

Supply of water (Litre per day) = 61Lpm x 5hrs/day x 60m/hr=18300 Litre per day.

The average amount of water the pump can deliver a day therefor is 18300litres per day.

The pump selection has also provided a very positive result so the system can be implemented.

Reservoir size recommendation

It is very practical that solar systems face cloudy days where they cannot perform well. So to insure

maximum security of supply the reservoir capacity should be 45,000 liters. This ensures three days of

storage.