6. Solar Pumping

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INTRODUCTION TO PHOTOVOLTAIC

PUMPING SYSTEMS

Yingli Solar Academy

Yingli Green Energy Spain

April , 24th2014

Alic ia Canut Montesinos

Project Engineer


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Table of content

1. Introduction

2. Selection of pump type

3. Photovoltaic Pumping System Components

4. Photovoltaic Pumping Systems more usual settings

5. Sizing

6. New technologies


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Table of content

1. Introduction




5. Sizing

6. New technologies


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Proprietary and Confidential

44

Introduction

In the cases below, the option of Pumping Photovoltaic System is the

most adequate. Even in developed countries, if the grid is located more

than half kilometer:

Solar water pumping option is feasible for many agricultural producers.

The equipment available in the market are reliable, durable and easy to operate.

The initial cost is relatively high compared to other traditional options, but may be more

economical to long term due to its low cost of operation and maintenance.


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Introduction

The benefit of this pump technology has a greater impact when it is accompanied by

an overall improvement of the farming or ranching.

There are still vast rural areas where they do not reaches the conventional electricity

grid.

Water for human consumption or pets, characterized by low power demands, are still

taken from wells or rivers.

People do not have irrigation systems, or those they have, are inefficient.

Fossil fuels supply is very irregular or non existent.


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Table of content

1. Introduction




5. Sizing

6. New technologies


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77

Selection of pump type

Selection of pump technology.

Id N o m b re d e t a r e a D ur ac i n C om ienzo

1 Senelec_Senegal 2 MW p 1 9d a s jue 27/ 03/14 lun 21/ 04/14

2 C ont r act S i gn at ur e 1 9 d as jue 27/ 03/14 lun 21/ 04/14

3Pr ecedent s C ondit i ons C ompli a n c e 2 7 d a s lun 31/ 03/1 4 d o m 04/ 05/14

4 G eot echnical S tu dy 1 7 d as lun 31/ 03/14 lun 21/ 04/14

5 Topographi c S tu dy 4 d a s lun 31/ 03/14 jue 03/ 04/14

6 R ecibo D ow npayment 10dasmar 22/04/1 4 d o m 0 4 / 0 5 /142

7 Acces & St ock area 33dasvi e28/03/ 1 4 v i e 0 9 / 0 5 /14

8 Engi neer i n g 1 05 d as lun 05/ 05/1 4 m i 24/ 09/143

Id N o m b re d e t a r e a Du r a c i n C o m ienzo

1 Senelec_Senegal 2M Wp 1 9 d as jue 2 7 / 0 3 /1 4 l un 21/ 04/ 14

2C ont ract S i gn at ur e 1 9 d as jue 2 7 / 0 3 /1 4 l un 21/ 04/ 14

3 Precedent s C ondit i ons C ompli a n c e 2 7 d a s lun 31/ 03/ 14dom 04/ 05/ 14

4 G eot echnical S tu d y 1 7 d as lun 3 1 / 0 3 /1 4 l un 21/ 04/ 14

5 Topographi c S tu dy 4 d a s lun 3 1 / 0 3 /1 4 j ue 03/ 04/ 14

6 R ecibo D ow npayment 10dasmar 22/04/14dom04/05/142

7 Acces & St ock area 33dasvi e28/03/14 vi e09/05/14

8 E n gi n ee ri n g 1 05 d a s lun 05/ 05/ 14mi 24/ 09/ 143


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Table of content

1. Introduction




5. Sizing

6. New technologies



99

Photovoltaoc Pumping System Components



1010

Modules:

Operation is defined by

I-V curve, radiation andtemperature.




1111

Batteries:

They are not often use in Pumping PV System.

Are necessary if there are no deposits to accumulate water or

when the flow rate, given by the well, doesnt cover demand

during the hours of sun. Also if an alternative use the generator is

given.

They have the advantage of allowing the operation of the pumpat any time and at constant power.




1212

Regulators:

They have assigned two basic functions:

1 -. Prevent Overload Generator batteries.

2 -. Prevent battery discharge more than permissible.




1313

Converters:

They can convert DC / DC and DC / AC.

The topology and control of DC / DC allows the system always

works at maximum generator power. It is called MPPT.

The DC / AC are required for connection of induction motors.

Normally incorporating a MPPT. Those are the inverters.




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Maximum peak power Tracker (MPPT):

Topology.




1515

Maximum peak power Tracker (MPPT):

Control




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Inverters

They have control over the voltage and frequency.

The knowledge of the wave shape is essential.

All current models have high efficiencies




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Single Phase Inverters (Square wave):




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DC Motors:

Classics (blades): maintenance problem

They have the advantage of high efficiency and easycontrol.




1919

AC Motors:

Induction or asynchronous, very robust and economic. Require

little maintenance.

They have the disadvantage of the inverter and its control is

more complex.




2020

Pumps:

Volumetric and positive displacement

Centrifugal



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2121

Pumps:

Positive displacement (of piston and diaphragm, mainly). Ideals

for low flow and high altitudes gauge.



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2222

Pumps:

Require a very high starting torque.



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2323

Pumps:

Dynamic exchange or amount of motion (centrifugal). For large

flows and small and medium altitudes.

They are very simple, they have few moving parts and the starting

torque is very low, so it makes them ideal for using with engines

induction ..

They can be installed on the surface or submerged.



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Pumps:

Surface

Centrifugal pump

.

SumergeCentrifugal pump



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Table of content

1. Introduction



4. Photovoltaic Pumping Systems more usual

settings

5. Sizing

6. New technologies


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Photovoltaic pumping systems more usual settings


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2727



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DC solar pumping:



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2929

Equipment with AC Motor.



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Coupling generator - engine - pump.

Curve A:Centrifugal pumps or

battery systems

Curve B:positive

displacement pumps

Curve C: Point Tracking

maximum power system



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3232

Pumping battery support:



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Table of content

1. Introduction




5. Sizing

6. New technologies


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3434

Electric energy hydraulic energy + losses

Applications

Irrigation

Domestic use

Sizing

Maximumefficiency is

looked for


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Factors determining the configuration:

Hydraulic conditions :Evaluating the necessary hydraulic power.

Depth water level in the well under the surface

Static water lift height

Dynamic head: losses in pipes and fittings

Power supplied by generator

Sizing

Dynamic head: Hd = Pd - did+ Hc + heqt


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Photovoltaic along day: Solar Radiation: Evaluating the available

solar energy.

Weather Condition

Dimensioning the PV generator:Determining the peak power of the generator that is necessary set to

satisfy the water needs throughout the year.

Considerations:

1) It is supposed to work under standard conditions (25 1000 W/m2).

2) Point coincides with the MPPT work all day.

Sizing


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Electric energy needed = E. hydraulic /(average daily generator).Electric power generator (25 - 1000 W/m2).

(1)

Pp: CEM Electric Power (W).

g: gen performance. FV at 25 C.

A: Active Area of the modules.

(2) (2)

Ee: daily electricity (kWh).

fv= monthly average yield on Daily Generator operating conditions.Gdm = monthly average daily radiation incident on the plane of

generator (kWh/m2 day).

Sizing


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(3)

Fm = average coupling factor (ratio of the electrical energy generated in operationconditions and the electricity that would be generated if the system worked in the maximum

power point).

It can be taken as Fm = 0.95 for MPPT systems monitoring, 0.9 to centrifugal

pumps and 0.8 to other pumps.

= Coefficient of variation of the power with the cell temperature(from 0.004 to

0.005 / C).

Tc = daily average temperature of the modules during daylight hours.

Sizing


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The electrical energy required is given based on performance

Average daily motor subsystem - pump.

(4)

Substituting into equation 1 equation 2, 3, and 4, the power required peak

watts, depending on the Eh, radiation and engine performance subsystem

- pump is:

Sizing


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Tc can be estimated from the average ambient temperature and Global

incident irradiance G in the plane of the generator (average values

daytime):

Tc = Ta + 0.03 G.

The correction value of T in the equation can be replaced by

Ft = (1 - (Tc-25)) = 0.8 to 0.9 for warm and cold weather climates

respectively.

Sizing


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Ones the necessary pumping equipment is already defined.

Regarding type of pumps, manufacturers usually specify the diameter and

material of the pipe.

Sizing


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Table of content

1. Introduction




5. Sizing

6. New technologies


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Variable Frequency Drive: The

range of allowable stresses for the

drive MX2 or RX are:

220V models: from 173Vcc to 400VDC,

recommended 310Vcc

400V models: 345Vcc up to 800Vdc,

recommended 535Vcc

New technologies


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Single Phase

New technologies


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Three Phase

New technologies

Documents

6. Solar Pumping