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Solar-Powered Water Heating Systems

A novel alternative Energy solution using Solar and electricity to heat water in existing and new electrical hot water systems. The simplicity of this system means that there is little modification required to an existing electrical hot water system, and makes the installation of a new system as simple as it has always been with grid electrical supply.

USEDASUN utilizes photo voltaic solar panels to generate electricity in an innovative way to heat water, while saving you on electrical bills.

• No more complicated vacuum tubes on your roof.
• No more recirculating pumps required.
• No more complicated heat pump installations.
• No more extra weight on your roof from all the extra equipment to heat your water.
• No batteries required as it runs directly off the sun.

The use of a boost converter, means less power lost over long distances whilst allowing an easier transmission of power with the boosted voltage. Innovative Maximum Power Point Tracking (MPPT) techniques, increases the energy that is converted into the hot water system. These innovative ideas allow this system to use solar energy more efficiently, reducing the amount of equipment required.

Making it Easy: A Simple Guide to Our Process

When clients express their desire to provide their own panels, a range of options becomes available for them to fulfill their requirements. This choice grants clients the flexibility to explore various pathways and strategies to meet their specific needs and preferences.

  • ONE

    For use with a 3KW geyser element, the minimum input voltage to the controller is 180V MPPT D.C. voltage to get any power flowing into the element.

  • TWO

    The highest open circuit input voltage the solar geyser unit can handle is 400V D.C.


    The maximum amount of solar power the standard solar geyser controller can handle is 1,600W or 1.6kW.

  • FOUR

    The minimum PV input recommended, depending on your area is 900Watts for the single geyser controller. The amount of power can be increased at any time, provided the DC to DC converter is matched accordingly if required.

  • FIVE

    The maximum geyser element that the solar geyser can handle is 3kW.

  • SIX

    The minimum size of element can be as low as 500W, however the amount of PV panels should be adjusted accordingly to not exceed the element power.


    In the case you use your own panels, and not our high voltage panels, you must use a boost voltage converter between the panels and the controller, referred to as ‘Booster’. Please let us know what panels you are going to use, so that we can match the converter to the controller.

Making it Easy: A Simple Guide to Our Process

When opting for a preassembled unit, installation becomes remarkably straightforward. Essentially, you’ll need to connect just two wires from the solar panel to the input and attach the geyser element to the output. These preassembled units come in two fundamental types for your convenience.

  • ONE

    On a base plate, intended for installation in the ceiling near the geyser.

  • TWO

    In an IP65 orange enclosure, intended to be placed on the outside wall of the house possibly under the eaves, out of direct sunlight, to reduce ambient heating of the enclosure during operation.

Exploring Preassembled Unit Variations

Basic System

  1. Solar Geyser Controller
  2. Mains Back up relay
  3. DC circuit breaker to isolate the PV panels
  4. Mains Isolator
  5. Sturdy metal base plate
  6. Prewired and tested for proper functionality
  7. DIN Rail terminals for easy connection to current installation


  1. Basic system, as above, includes a kW Hour meter with built in time switch, temperature probe and display which is installed in a convenient position in the house, which shows kW Hour saved, real time clock with 3 programmable switching times, and manual over ride.
  2. Basic System as above but installed inside an IP65 wall mount enclosure, includes a kW Hour meter with built in time switch, temperature probe and display which is installed in a convenient position in the house.
  3. The addition of a recommended electrostatic surge arrester, to protect the panels and electronic controllers.

PV Panels

When it comes to selecting PV panels that align with your specific requirements, there is a plethora of options at your disposal.

  1. Use 5 high voltage PV panels, 63V – 265/270W panels which will give 315V D.C. at 1325/1350W – direct connection to geyser controller no convertor/booster required
  2. Use 5 off standard 270W panels with a voltage convertor/booster on each panel – 305V D.C. at 1350W (5 off HVPVCB-30V300V265W and one HVPV-5W – High Voltage Converter Connector unit)
  3. Use 5 off standard 270W panels with a voltage 150V to 300V convertor/booster  – 305V D.C. at 1350W (1 off HVPVCB-120V300V1200W – requires suitable MC4 ended extension from PV panels to geyser unit)
  4. Use 4 off 330W panels with a voltage  150V to 300V convertor/booster  – 300V D.C. at 1320W (1 off HVPVCB-120V300V1200W  – requires suitable MC4 ended extension from PV panels to geyser unit)
  5. Use 4 off 350W panels with a voltage 150V to 310V convertor/booster – 310V D.C. at 1400W (1 off HVPVCB-120V300V1200W  – requires suitable MC4 ended extension from PV panels to geyser unit)

Additional Information & Requirements

Our solar water heating system is an excellent choice for a family of four who use hot water conservatively. If you require additional hot water, you can seamlessly switch over to the grid. To ensure optimal performance, it’s essential that the solar panels face north with a typical angle of 22° and remain free of shadows throughout the day. Conveniently, the panel placement should also allow for easy cleaning when necessary. Please be aware that any quoted prices do not include VAT and installation costs, which can vary between R3,500.00 and R6,500.00 depending on site-specific factors determined during an inspection. Prices are for collection at our Selby, Johannesburg premises, and the quoted price is valid for 30 days, subject to the availability of current stock. Payment in full is required before collection.

If you require assistance in selecting a booster or have any questions, please don’t hesitate to contact Usedasun for expert guidance. Additionally, we’re excited to introduce our Dual Geyser System, capable of heating two geysers simultaneously. Keep in mind that this system requires double the number of PV panels compared to the single geyser setup. In the case of the Dual Geyser system, doubling up on PV panels and the potential omission of a booster due to higher voltage bring the advantage of redirecting full power to the remaining geyser when one switches off.


Options Based on Budget and Application

Select the system that best suits your budget and application needs for efficient and convenient solar water heating.

Any question?

This system is manually controlled with a switch or geyser timer inside your house. It can also include a temperature indicator if needed.

Join the Alternative Energy Revolution Today!

Are you ready to take your first step towards a more sustainable and energy-efficient future?

With our solar and solutions, you can reduce your carbon footprint, lower your energy costs, and contribute to a greener planet. So what are you waiting for? Contact us now!