Solar PV has become a popular choice for South African homeowners looking to reduce their electricity costs. One of the biggest energy users in a home is the geyser, which naturally raises the question: should you use your solar panels to heat the geyser directly?

It sounds like a good idea. However, there is another option worth considering.

Combining a solar PV system with an efficient heat pump can make better use of your available roof space while still providing plenty of hot water for your home.

The problem with using PV to power a geyser element

A conventional geyser uses an electrical element to heat the water. If the element is rated at 3 kW, it uses electricity to produce heat at roughly a 1:1 ratio. In simple terms, one unit of electricity gives you approximately one unit of heat.

There is nothing wrong with this technology. It has been used successfully for many years.

The issue is what happens when the geyser reaches its required temperature.

The element switches off.

Your solar panels may still be producing electricity, particularly during the middle of the day when solar generation is at its highest. That electricity then needs to be used somewhere else in the house, stored in a battery, exported to the grid where possible, or potentially curtailed.

There is also the question of roof space. If a large portion of your solar PV system is being sized around the electricity needed to heat water, you may need more panels than you otherwise would.

A heat pump changes the equation

A heat pump works differently from a traditional geyser element.

A heat pump works a little differently from the element in a normal geyser. A heat pump doesn’t heat water in quite the same way as the element in a normal geyser. It takes heat from the air around the unit and moves that heat into the water. Electricity is still needed, but far less of it is required to produce the same amount of hot water.

For example, a heat pump with a COP of around 3.5 to 4 can deliver roughly 3.5 to 4 units of heat for every unit of electricity it uses. That’s a big difference when you compare it with a standard geyser element, where one unit of electricity gives you about one unit of heat.


Of course, the exact performance won’t always be the same. Things like the outside temperature, the temperature of the water and how the system has been installed all make a difference. Even so, the saving compared with a traditional geyser element can be significant.

Your solar power can be used throughout the home

This is where the combination of solar PV and a heat pump becomes particularly useful.

During the day, your solar panels produce electricity. If the water temperature has dropped, the heat pump can use some of that available electricity to heat the water.

Once the water reaches the required temperature, the heat pump stops.

The solar panels can then continue supplying electricity to the rest of the house.

Your refrigerator, washing machine, computers, lights and other appliances can all make use of the available solar energy. If you have batteries, they can also be charged.

Instead of dedicating a large amount of solar generation to a conventional heating element, the energy can be shared across the household.

Making better use of your roof

For many homeowners, roof space is limited. You want every solar panel to contribute as much as possible to reducing your reliance on grid electricity.

Using an efficient heat pump means you don’t necessarily need to generate as much electrical energy specifically for water heating.

This can be particularly helpful in designing a new solar installation. Instead of just adding more panels to a high demand geyser element, you can think about the total energy needs of the house and use a heat pump to reduce the amount of electricity needed to produce hot water.

A practical combination for South African homes

Solar PV and heat pumps work well together because they perform different jobs.

The solar panels generate electricity. The heat pump uses that electricity efficiently to produce hot water. When the hot water is ready, the heat pump switches off and the solar power becomes available for other household requirements.

It is a simple concept, but it can make a meaningful difference to how efficiently your solar system operates.

At SunScan, the focus is on helping homeowners find practical and energy-efficient solutions for hot water.  A heat pump, combined with correctly sized solar PV, can help you make better use of your available roof space while reducing the electricity required to heat your water.

The goal isn’t simply to install more panels.

It is to get more useful energy from the panels you already have

If you’ve already have a geyser at home and are thinking about solar, you might be wondering whether you have to replace the geyser as well.

In many cases, you don’t.

This is actually one of the first things worth checking before spending money on a completely new hot-water system. If the geyser is still in good condition, it may be possible to keep it and add a heat pump, solar thermal collector, or a combination of the two.

That can be a much more practical way of improving the system.

Adding a heat pump to an existing geyser

A heat pump can be used with an existing geyser in suitable installations. The geyser continues to hold the hot water, while the heat pump does the job of heating it.

The difference is in the way the water gets heated.

A heat pump works differently. It takes warmth from the air around the unit and uses it to heat the water. The electricity is mainly needed to run the heat pump and move that heat where it is needed.
The result is that you don’t need as much electricity to get the water up to temperature. That’s the main reason people look at heat pumps when they want to cut down on the cost of running their geyser.

And if your existing geyser is still in good shape, there’s no reason to throw it away just because you want to change the way you heat the water. In the right setup, the heat pump can work with the geyser you already have.

The existing tank may still have plenty of life left in it.

What happens if you already have solar?

Solar PV is slightly different because the panels produce electricity rather than hot water.

That electricity can be used anywhere in the house. You can run appliances with it, charge batteries and, of course, use it to run your hot-water system.

This is one reason solar PV and a heat pump make such a good combination.

During the day, your panels are producing electricity. If the water in the geyser needs heating, the heat pump can use some of that power. Once the water has reached the required temperature, the heat pump stops.

The solar panels don’t stop, though.

Whatever electricity is still being produced can go towards the rest of the house.

Can you have solar and a heat pump on the same geyser?

In a suitable installation, yes.

This is probably one of the better ways to get more out of an existing geyser.

The solar PV system supplies electricity, the heat pump uses that electricity efficiently to heat the water, and the existing geyser provides the storage.

There is no need for the heat pump to be running simply because the sun is shining. It runs when the water needs heating.

That point is worth considering when you’re looking at the size of a solar installation. If you use a conventional geyser element, a lot of electricity will be needed to heat the water. With a heat pump, much less electrical energy is required for the same job.

The difference can help you get more from the solar panels you already have.

Is every geyser suitable for a retrofit?

Not automatically.

The condition of the geyser is important. If the tank is old, leaking or already showing signs of trouble, putting additional equipment onto it may not be the best use of your money.

The size of the geyser needs to be considered too. A small household with relatively low hot-water use has different requirements from a large family.

Then there is the installation itself. The position of the geyser, available space for the heat pump, pipework and electrical supply all need to be checked.

It’s much better to look at these things before buying equipment than to discover afterwards that something needs to be changed.

Retrofitting can save you from replacing a perfectly good geyser

The idea behind a retrofit is fairly simple. If something you already own is still useful, why replace it unnecessarily?

A good existing geyser can potentially become the storage part of a more efficient hot-water system.

You can add a heat pump to reduce the electricity needed for heating, and solar PV can provide the electricity for the heat pump while also supplying the rest of the home.

For some households, installing both at the same time could make sense. For others, starting with a heat pump and adding solar later may be the better route.

There isn’t one answer for every house.

At SunScan, we can recommend an installer who can assess your existing geyser and look at what can realistically be added to it. The condition of the geyser, your hot-water requirements and the available space all form part of that decision.

So before you remove a geyser that is still working properly, have a look at the retrofit options first.

You may already have the most expensive part of the system sitting in your home. It might just need the right technology added to it.

Water heating takes 30 to 50% of a South African household’s electricity bill, by Eskom’s own estimate, and the geyser is usually the single biggest item on it. That’s the number a solar geyser and a heat pump both go after, and both do it well, cutting that portion of the bill by more than half in a typical home. Which one suits your house is a different question, and it’s the one we spend most of our week answering, so this is the walk-through we’d give you at your own front door.

When a Solar Geyser Is the Right Call

The whole system depends on direct sunlight, so the first thing to check is your roof:

• An unshaded, north-facing roof: collectors want direct sun through the middle of the day. Get that right and the tank has done most of its heating before lunch.
• A long lifespan: a well-maintained system runs 15 to 20 years, and the simplest versions have almost no moving parts to service.
• An electric backup for winter: systems carry a backup element for overcast weeks, so you still have hot water after days of rain.
• A geyser too young to replace: a conversion keeps your existing tank and adds the collector, which costs less than a full new system.

When a Heat Pump Wins

A heat pump works like a fridge in reverse, pulling warmth out of the outside air, and it delivers three to four units of heat for every unit of electricity it draws:

• No roof required: it sits at ground level beside the geyser, which settles the question for shaded houses, flats and estates with rules about what goes on the roof.
• Cloudy weather has little effect: it runs on air temperature, so it loses a little efficiency in a cold week and keeps working.
• A straightforward retrofit: it connects to the electric geyser already in your ceiling, and the tank stays where it is.

What They Cost in 2026

Current market pricing in Cape Town runs like this, installed:

• A solar geyser: R22,500 to R39,500 depending on tank size and system type, with conversions of an existing geyser coming in lower.
• A heat pump: R25,000 to R45,000 depending on capacity.

Both routes typically pay for themselves in three to five years through the electricity they stop using, and both keep working for a decade or more after that. Exact pricing depends on your tank size, your roof and how much hot water your household uses, so a final figure needs a quote.

The Bill Only Moves in One Direction

Eskom’s tariff rose 13.67% in April 2026, and every month of heating water on a plain electric element is another month at full price. SunScan supplies SABS-tested solar geysers and heat pumps with warranties of up to 5 years, fitted through our network of accredited installers across Cape Town and the Western Cape, and in most homes the roof settles the choice.

 

At SunScan, our commitment to innovation and excellence in solar water heating has always been at the forefront of what we do. We are thrilled to announce the launch of our new range of high-performance flat plate collectors, the Premium Performer, a testament to years of dedicated research, rigorous testing, and an unwavering focus on quality. Read more below or watch our YouTube video

The Edge of Experience: Tested at SABS

For over a decade, SunScan has invested countless hours in comprehensive product testing at the South African Bureau of Standards (SABS). This isn’t merely a formality; it’s a crucible where our designs are pushed to their limits, revealing insights that are invaluable. This deep well of knowledge, gained from real-world simulations and stringent performance evaluations, has given SunScan a distinct advantage. It allows us to engineer products that not only meet but consistently exceed industry benchmarks for both performance and durability, especially crucial in South Africa’s diverse climate.

Unpacking the Premium Performer: Technology That Delivers

The Premium Performer isn’t just an incremental upgrade; it’s a leap forward in solar thermal technology. At its heart are two critical advancements:

1. High-Grade Copper: The Conductor of Efficiency

We’ve chosen to utilize high-grade copper for the header and risers tubes within the Premium Performer collectors. Copper is renowned in the solar thermal industry for its exceptional thermal conductivity, meaning it transfers heat from the sun’s rays to your water with remarkable speed and efficiency. This superior conductivity ensures that more of the sun’s energy is captured and converted into hot water, reducing the need for auxiliary heating. Furthermore, high-grade copper offers unparalleled corrosion resistance, guaranteeing longevity and consistent performance even in challenging water conditions often found across South Africa.

2. The Latest Blue Selective Coating: Trapping Every Ray

Complementing the high-grade copper is the application of the latest blue  selective coating. Unlike standard black paints that merely absorb sunlight, a selective coating is engineered to maximize solar absorption while minimizing heat re-emission. This advanced surface acts like a one-way valve for heat: it efficiently captures solar radiation (short-wave energy) but significantly reduces the amount of thermal radiation (long-wave energy) that escapes back into the atmosphere. The result is a collector that retains more heat, performs exceptionally well even on cooler or windier days, and ultimately delivers hotter water more consistently.

Together, these innovations enable the Premium Performer range to outperform most other panels on the market, setting a new standard for efficiency and reliability. 

A Legacy of Performance, Expanded for Your Needs

Our existing Class 1 flat plate collector range has been a cornerstone of countless successful solar installations, known for its robust performance and reliability. We are proud to continue offering this trusted range. The Premium Performer builds upon this solid foundation, leveraging the same proven engineering principles but integrating the advanced materials and coatings to unlock even greater thermal output.

During extensive real-world testing, the performance figures for the Premium Performer have consistently exceeded our expectations, demonstrating its capacity to deliver superior hot water generation and energy savings for homeowners.

Tailored to Your Home: New Sizing for Modern Demands

Understanding that every home and family has unique hot water requirements, we have refined our sizing range to align with evolving market trends and consumption patterns. This ensures optimal system design and maximum efficiency for every installation.

Our Class 1 Flat Plate Collector Range:

• 1.5m² vertical: Ideal for a 100L geyser, perfect for smaller households or supplementary heating.
• 2.0m² vertical: Suited for a 150L geyser, a popular choice for average family needs.
• 2.5m² vertical: Designed for a 200L geyser, providing ample hot water for larger families.

For larger systems, such as a 300L geyser, these panels can be easily connected in parallel. For instance, you could use either two 1.5m² panels or, for higher usage demands, two 2.0m² panels to ensure consistent hot water supply.

Introducing the Premium Performer Range:

Our new Premium Performer range offers even greater flexibility and performance:

• 2.0m² vertical: A high-performance option for standard installations.
• 2.0m² horizontal: Perfect for aesthetic integration on roofs with limited vertical space or specific architectural requirements.
• 2.4m² vertical: An optimized size for enhanced performance, particularly effective for 200L-250L systems, offering rapid recovery rates.
• 2.4m² horizontal: Combining high performance with flexible horizontal mounting, ideal for modern roof designs.

The SunScan Promise: Quality You Can Trust

In a market flooded with options, remember this crucial distinction: if it doesn’t say SunScan, then it isn’t the real deal. Our name is synonymous with quality, durability, and performance, backed by years of South African expertise and rigorous testing. Choose SunScan, and choose confidence in your solar water heating solution.