Wilo-Actun OPTI-MS | Wilo

Wilo-Actun OPTI-MS

Wilo-Actun OPTI-MS – Autonomous, optimised water supply using solar power.

Your advantages
Wilo-Actun OPTI MSH

Wilo-Actun OPTI-MS – Autonomous, optimised water supply using solar power.

Ensuring a reliable water supply in arid and remote regions not connected to the power grid is a challenge. The new solar-powered Wilo-Actun OPTI-MS, provides a solution which is independent of the mains power supply for an effective and reliable water supply.

Your advantages

  • Fully autonomous and cost-efficient water supply utilising solar power
  • Easy electrical installation via integrated frequency converter and without the need for parametrisation
  • Optimised water output thanks to high hydraulics and motor efficiencies and dynamic MPPT (Maximum Power Point Tracking – ensures the operation of the solar panel at maximum performance level)
  • System-specific flexibility thanks to wide range of services
  • Increased durability and reliability through high-quality materials and an encapsulated motor design
  • Additional operational reliability by using integrated safety devices

The autonomous water supply using solar power – for irrigation and drinking water supply

Key Facts

650 people can be supplied with water using a Wilo-Actun OPTI-MS* *80 m³/d at 6 kWh/m²/d; 120 l/person, source: solar.wilo.com

149.6 million kilometres is the distance the sun travels on the centre path to reach the Earth in order to power solar pump systems

< 1 year amortisation time: amortisation time of less than one year for the solar pump station as a replacement for diesel-generator-based systems is feasible


Optimum water supply in all weathers

Dynamic MPPT

Integrated Maximum Power Point Tracking guarantees maximum water output and efficiency.

If there is a change in the exposure level of the solar modules, the maximum performance point (MPP), current, and power are offset in relation to the voltage. The MPPT algorithm identifies the ideal ratio between electric current and voltage to consequently dynamically actuate MPP. As a result, the available exposure to sunlight is optimally converted into electrical power to maximise the water supply.

This means: For the same solar radiation intensity and the same configuration of photovoltaic modules, Wilo-Actun OPTI can pump more water than other solar-powered submersible pumps.

Dynamisches MPPT für Wilo-Actun OPTI
Landwirt/Bauer steht im Feld

“Easy installation and excellent support from Wilo.”

Mohamed Bouchta, installer, Morocco

Contractor Uwe

“An autonomous system thanks to solar power.”

John Stuart, operator, UK

Configuration information and tips

Easy selection guide for solar pump systems

The geographical conditions on site play a crucial role when using submersible pumps with solar power. Different regions are subject to more or less exposure to sunlight and this affects the volume flow of our solutions.

Here are guide values for the average hours of sunshine in your region to enable you to design your solution better. You are welcome to use our configuration service and our online configuration software Wilo-Select SOLAR as part of your planning.


Additional help in configuration is provided by our calculation, which you can use to calculate the typical volume flow to help select the solar pump system:

Easy selection guide for solar pump systems

Find out which solution is suitable for your individual situation here.

Grafik zeigt die tägliche Sonneneinstrahlung für Europa in kW/m3/d

Wilo-Select SOLAR configuration software

Flexible, convenient, efficient and powerful – Wilo-Select SOLAR
Find out how to select your system here step by step.


Do I have to start the solar pump every day?

No, both the OPTI-MS and OPTI-QS have sophisticated electronics which start the pump autonomously, provided there is sufficient solar power.

Which previous knowledge is required to adjust the solar pump?

No previous knowledge is required since the pump’s electronics automatically adjust to local conditions, making adjustments unnecessary.

Do I need an external control device to operate the solar pump?

No, an external control device is not required. However, the Wilo-MS Control can be used to expand functionality, e.g. by using sensors.

Which accessories are required in order to connect a float switch, for example to fill a tank?

The Wilo-Actun OPTI-MS offers a signal cable input that can be directly connected to a float switch using a submersible cable. The Wilo-Actun OPTI-QS can be equipped with the optional Wilo-QS Stop Module which can then be connected to the float switch.

Which additional protective devices are recommended?

The Wilo-Actun OPTI-MS and the Wilo-Actun OPTI-QS come pre-equipped with the most important protective devices. This includes dry-running protection, temperature monitoring and monitoring of electrical parameters (overvoltage and undervoltage, excess current).

Which photovoltaic modules can be used with the solar pumps?

In general, you can use photovoltaic modules from any manufacturer and specification as long as the voltage ranges of the solar pumps are taken into account. The Wilo-Actun OPTI-MS can be operated between 90 and 400 VDC and the OPTI-QS between 70 and 190 VDC. In addition, Wilo offers high-quality, German-made photovoltaic modules that can be combined with the solar pumps.

Can the solar pumps also be connected to an alternating current?

The Wilo-Actun OPTI-MS can be connected to both a direct current of the photovoltaic modules and an alternating current (e.g., 1~230 V, 50 Hz). The Wilo-Actun OPTI-QS can only be operated using the direct current of the photovoltaic modules.

How do I find out which solar pump I need?

For quick and easy configuration, you can use our “Easy selection guide for solar pump systems”. For an especially precise and individualised configuration, we recommend using our online tool Wilo-Select SOLAR available at solar.wilo.com. The tool takes your requirements and installation location into account and provides you with precise predications about the amount of daily water output in different months.

How many photovoltaic modules do I need?

The number of required photovoltaic modules can be found in our “Easy selection guide for solar pump systems” [HA1] or by using our Wilo-Select SOLAR online tool at solar.wilo.com. These take the relevant voltage range of our solar pumps into account: The Wilo-Actun OPTI-MS can be operated between 90 and 400 VDC and the Wilo-Actun OPTI-QS between 70 and 190 VDC.

How can I ensure water supply during night-time?

Since solar energy cannot be used at night to pump, several alternative water pumping options are conceivable. One option is to use a tank that has been appropriately dimensioned as a buffer for the hours at night. Another option is to connect the Wilo-Actun OPTI-MS to alternating current sources, for example, to a diesel generator or power grid.

How can I store solar energy?

We recommend using water tanks as buffers for indirectly storing solar energy. These can contribute to securing the water supply at night and also during lower-performing seasons.

Can I also use the system for heating?

Wilo-Actun OPTI solar pumps are only suitable for pumping clean water up to a temperature of 35 °C. Wilo also offers dedicated pumps for solar thermal technology.

How can I lengthen the cable on the pump?

A cable connector with instructions is included in the scope of delivery. Submersible cables from Wilo can be connected to the short cable of the pump using this connector.

Can existing photovoltaic systems be used?

Solar pumps in the Wilo-Actun OPTI series can be combined with existing photovoltaic systems as long as the voltage ranges are compatible: The Wilo-Actun OPTI-MS can be operated between 90 and 400 VDC and the Wilo-Actun OPTI-QS between 70 and 190 VDC. In addition, the specifications of your photovoltaic modules can be saved in our online tool at solar.wilo.com. Using your specifications, the configuration then validates the photovoltaic system and solar pump combination.

How often do the solar pumps need to be maintained?

The Wilo-Actun OPTI submersible pumps are generally low-maintenance. Regular maintenance intervals do not need to be planned.

Irrigation - Your autonomous irrigation system for agriculture.

Drinking water supply - Your reliable solution for wells and surface waters.

Wilo-Actun FIRST (4")

Raw water intake from boreholes for irrigation.

Wilo-Xiro SPI 6"

Wilo-Xiro SPI (6" – 10")

Raw water intake from boreholes for irrigation.

Wilo-Sub TWI (4" – 10")

Raw water intake from boreholes for drinking water supply.

For more comfort: Discover the Wilo-Assistant app

  • QR code scanner
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    Scan all the product images in our brochures marked with the AR (augmented reality) symbol to obtain more information.
  • Product search
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  • Instructions
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  • Also available offline
    Wilo-Assistant also provides the user with targeted access to product information and know-how relating to pump technology. Most of the data content and functions are installed directly on your smartphone and are therefore available even when you aren’t connected to the Internet


Got a query or need advice on Wilo-Actun OPTI? Then simply fill in the contact form and we’ll get in touch:

Contact form
Series description
Wilo-Actun OPTI-MS


Multistage submersible pump in tie strap version (MSI) or as a progressive cavity pump (MSH) for vertical or horizontal installation


  • Specially designed for operation with photovoltaic modules
  • For water supply and drinking water supply from boreholes and rainwater storage tanks
  • Process water supply
  • Sprinkling and irrigation
  • Pressure boosting
  • For pumping water without long-fibre and abrasive constituents


  • Fully submersible, multistage submersible pump:
    • as centrifugal pump in sectional construction (MSI) or
    • as progressive cavity pump (MSH)
  • with integrated non-return valve
  • with corrosion-free, encapsulated permanent magnet motor with water-glycol filling
  • Built-in frequency converter
  • Integrated software algorithm MPPT (“Maximum Power Point Tracking”) for applications with solar modules
  • Pre-installed signal cable for direct connection to signal transmitters (e.g. float switches)

Scope of delivery

  • Submersible pump with connection cable (2.5 m)
  • Casting resin cable connector with integrated water level sensor
  • Installation and operating instructions
  • Hydraulics for self-assembly (MSH only), incl. installation instructions and installation accessories
  • Adapter for pressure connection 1½" on 2" (only types OPTI-MSI4.08-..)

Type key


Wilo-Actun OPTI-MSH4.02-02


Product family


Series designation


Type name

MS = Multipower Solar


Hydraulic version

H = progressive cavity pump

I = multistage centrifugal pump


Nominal diameter in inches


Rated volume flow in m3/h


Number of stages

Technical data

  • Operating voltage: 90 – 265 V AC or 90 – 400 V DC
  • Submerged operating mode: S1
  • Max. fluid temperature: 35 °C
  • Minimum flow rate at motor: 0.2 m/s
  • Max. sand content: 50 g/m3
  • Max. immersion depth: 150 m
  • Protection class: IP68
  • Pressure connection: Rp 1¼ – Rp 2


  • Hydraulics housing: stainless steel 1.4301 (AISI 304)
  • Impellers: stainless steel 1.4301 (AISI 304)
  • Hydraulic shaft
    • MSH: Stainless steel 1.4401 (AISI 316)
    • MSI: stainless steel 1.4301 (AISI 304)
  • Motor housing: stainless steel 1.4301 (AISI 304)
  • Motor shaft: Stainless steel 1.4057 (AISI 431)


Submersible pump as centrifugal pump in sectional construction (MSI) or as progressive cavity pump (MSH) for vertical or horizontal installation.


A multistage submersible motor centrifugal pump (MSI) with radial impellers in sectional construction or a progressive cavity pump (MSH) with helical rotor inside a twin-helix rubber stator. Integrated non-return valve. All parts that come in contact with the fluid are made of corrosion-free materials.


Single-phase current permanent magnet motor. Sealed and hermetically cast motor, resin-impregnated, with enamel-insulated winding, self-lubricating bearing, with water-glycol filling.

Frequency converter

Hermetically sealed frequency converter for direct operation using alternating current and direct current sources. The integrated software algorithm MPPT (“Maximum Power Point Tracking”) enables the available power to be matched in order to maximise the pumped volume flow (dynamic MPPT).

Safety functions:

  • Overvoltage protection
  • Excess current protection
  • Dry-running protection (via integrated sensor)
  • Temperature monitoring


The motor is cooled by the pumped fluid. The motor must always be immersed when operated. The limit values for maximum fluid temperature and minimum flow velocity must be adhered to. Vertical installation is possible with or without cooling jacket. Horizontal installation must be performed in conjunction with a cooling jacket.


Installation and operating instructions

Wilo-Actun OPTI-MS...

Article Number 6084879
Edition 2019-02
Page format 148.2 x 209.9 mm
Number of pages 372
PDF (6 MB)

General overview (Documents)

General overview 2021 International version

Edition 2020
Page format 209.9 x 297.0 mm
Number of pages 74
PDF (10 MB)

Certification booklet

Wilo-Actun OPTI-MS, Wilo-Actun OPTI-QS

Article Number 6089479
Edition 2020-09
Page format 209.9 x 297.0 mm
Number of pages 12
PDF (2 MB)

Brochure (Documents)

Wilo-Actun OPTI - Autonomous, optimised water supply using solar power

Article Number
Page format 209.9 x 297.0 mm
Number of pages 12
PDF (2 MB)

Easy selection guide for solar pump systems

Article Number
Page format 297.0 x 209.9 mm
Number of pages 2
PDF (682 KB)

Easy selection guide for solar pump systems

Article Number
Page format 297.0 x 209.9 mm
Number of pages 2
PDF (613 KB)

Easy selection guide for solar pump systems

Article Number
Page format 297.0 x 209.9 mm
Number of pages 2
PDF (671 KB)

Certificate REACH (Documents)

REACH regulation

Edition 2020-08
Page format 209.9 x 296.7 mm
Number of pages 4
PDF (1 MB)
Product list
Product descriptionMains connectionMotor diameter DMMax. delivery head HmaxMax. volume flow QmaxRated power P2Gross weight, approx. mArticle number