Project design > Pumping systems > Pumping system procedure

See also the Basics about pumping systems.

This page gives the full procedure for the development of a Pumping system in PVsyst.

First step:

As for any calculation variant in PVsyst, you should begin by defining rhe collector array orientation.

In the present time, a pumping system may be defined with one only sub-array, so that you cannot define several orientations. However tracking is allowed.

Second step:

Choose the "Water needs" button, page "Pumping Hydraulic Circuit".

You have to define the pumping circuit, i.e. choose among one of the three available systems:

-Pumping from a deep well, to a tank storage,

-Pumping from a lake or river, to a tank storage,

-Pumping into a pressurized tank, for water distribution.

and define the Hydraulic Circuit configuration (Storage Tank and Pipes).

Third step:

Page "Water needs and head definitions"

Define the water needs in m3/day (may be yearly, seasonal or in monthly values).

Define the pumping static depth if varying along the year (may be seasonal or monthly). The value defined here corresponds to the value "Level depth" or "Static depth" specified on the preceding page.

Fourth step:

Choose the "System" button, observe and play with "Pre-sizing suggestions"

The pre-sizing suggestions on the top of the dialog pre-evaluates some parameters (tank volume, pump and PV array power) required for meeting your pre-defined water needs requirements. See also "Pumping sizing" for the principle. You can play with the parameters for getting orders of magnitude. However this pre-evaluation is difficult and may be inaccurate, as performances are very different from one to another pump.

This tool only proposes some values, these values are not really used in your project.

Fifth step:

In the "System" dialog, page "Pump definition".

Choose a pump model, taking the nominal Head into account (pumps are coloured in green for suitable, orange for not optimal, or red for not suited devices).

Choose the number of pumps for reaching the required nominal power or FlowRate (all pumps wired and operating in parallel).

You have a summary of the pump capabilities, as well as of the set of pumps if you choose several ones.

This dialog also provides a little too for the calculation of the Hydraulic Power corresponding to a given Head x FlowRate product.

Sixth step:

In the "System" dialog, page "Sub Array design".

Choose a PV module (also Green/Orange/Red), and a suitable PV array configuration (proposed by PVsyst).

NB: This last choice may be dependent on the System Configuration which will be chosen during the next step (especially with direct coupling), . You will perhaps have to come back to this choice after your Configuration choice.

Seventh step:

Here you have to choose the control mode.

Again the Green/Orange/Red colours indicate the suitable choices, according to the previously chosen System type, Pump model and Pumps number. A collection of specific Warning messages explain the reasons of incompatibilities or poor design.

The chosen Regulation strategy fixes the available set of control devices.

There is a Universal Control device corresponding to each strategy, with all parameters automatically adjusted according to your system (the system-dependent parameters will be re-evaluated just before the simulation). You are strongly advised to use these Universal components during the pre-study of your system, getting ride of the controller constraints. A commercial device may be chosen when your whole system is well established.

If "Battery Buffered" configuration, you still have to define the battery pack.

In a next version of the program, it will be possible to specify an eventual back-up generator.

Eighth step:

You can open the Controller Device and check its parameters

All system running specificities are defined in the Controller/Regulation device. This includes namely the boundary operating conditions (Tank full, dry running, Power, Voltage, Current limits, etc.)

In most cases the controller holds parameters specific to the system configuration strategy, which should be defined by the user (for example, Irradiance thresholds for pumps cascading or array reconfiguration, converter input voltages, etc).

Nineth step:

PV array design, number of modules in series/parallel.

For MPPT converter devices, the procedure is analogous to the design of grid connected systems: you can specify a planned power and PVsyst will propose a configuration (use the button "Resize" for a complete resizing). You have to choose a number of modules in series for which the Voc(Tmin) doesn't exceed the VmaxAbs of the converter, and the Vmpp(TOper) should not be under the VmppMin of the converter.

The PV array sizing is particularly difficult when dealing with Direct coupling configurations: in these cases you have to match the Array Voltage with the Pump Characteristics. The "I/V matching" button shows a specific graph which should help for this task. A direct coupling configuration requires sometimes a specific kind of PV modules (number of cells is series). Modules which are not well suited will appear in orange in the PV modules list.

The number of strings is to adjust according the the power requirement of the pump in operating conditions. this is not always easy to obtain, due to constraints on the MPPT inputs of the real controllers.

Tenth step:

If no error in red, you are ready for the first simulation of your system.

Ultimate step (after your first simulations):

You may open the usual Array Losses dialog for modifying special array and wiring parameters (perhaps define the wire sizes … ).