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Get off the grid step-by step with a Hybrid Solar PV solution

Many people are looking for back-up power solutions for their homes and businesses to see them through unpredictable and productivity-killing Eskom load shedding. They are also fed up with the rocketing costs of electricity and mooted penalties for making alternative arrangements to get the power that Eskom cannot reliably or affordably supply. The parlous state of municipalities should also be of great concern, with outright collapses of services and governance a daily occurrence. It all compromises your productivity, safety, security, income and quality of life.

Any investment you make into an energy back-up solution must be with a long-term view to getting you closer to greater grid independence, step-by-step. It’s crucial to consider where South Africa’s energy future is headed, and what this means for your home, your business, your productivity and your security. Any money spent on an unsuitable back-up solution today detracts from your ultimate objective of grid-independence and self-sufficiency.

Start your journey effectively and affordably, with a scalable, quality solar PV hybrid solution that takes care of your immediate needs for back-up power during load shedding and power failures and allows you to scale up in future to self-generation by adding solar panels. Initially your system is configured as a back-up UPS type solution to provide backup only during outages. Then, as budget allows, expand with solar panels to generate your own power, providing back-up AND saving you a fortune in electricity costs.

Not all inverters offer this scalable functionality so it’s essential to work with a renewable energy partner who is experienced in this field and understands and works with your long-term objectives. Work with a qualified renewable energy partner with a solid and long-standing track record in the industry, and that will be around to support your system for many years to come.

In the current environment where everyone is scrambling for a solution to load shedding, fly-by-night operators and product manufacturers have exploded onto the market, with dire consequences for unsuspecting consumers. Avoid at all costs the cheap, quick fixes sold by newcomers to the industry looking to make a quick buck. No doubt they will be promising you the world with cheap inverters and substandard installations to save on costs in a quest to close a quick deal – which will ultimately leave you in the lurch and out of pocket.

There are inherent risks in buying products from unproven newcomers as they do not have the track record to prove they will be around to service the products and uphold warranty claims if necessary. They also do not have the experience, track record and hard-earned school fees of understanding which tech solutions are best suited to the South African market, are grid approved according to NRS-097 standards, and able to provide the back-up and support that your system will need over its’ lifetime and your changing needs. This is particularly the case in solar power where products have long warranty periods and expected lifetimes of 20 years+.

This is how you get off the grid step-by-step with a hybrid solar PV solution

Step 1:  Convert your electric geyser to a solar geyser

If you want to radically reduce your monthly electricity costs at the same time and get your home ready for solar PV and greater grid independence, take your water heating off the grid with a solar geyser. An electric geyser accounts for between 30-40% of your monthly electricity usage in a typical mid-income home, so this is the most crucial starting point to reducing your daily electricity load, and which means you can also buy a smaller and more affordable PV solution.

A 200-litre solar geyser, fully installed is around R27 000. Do this first!

Looking at an average electricity bill of R3000 per month, a family of four could expect to conservatively save about 30% of this bill by installing a correctly sized solar geyser.

That’s R900 per month which is R10 800 per annum. Your solar geyser will completely pay for itself in under three years. From day 1, you will cut your electricity spend to Eskom by around 30% – every month.

Step 2: Start with a hybrid inverter and li-ion battery solution that is initially configured like a UPS to provide back-up for load shedding and outages.

Then as your budget allows, you can add solar panels and additional li-ion batteries to provide you with a full hybrid system for self-generation, electricity savings and battery-back up.

For purposes of this illustrative exercise, we used a Sunsynk inverter configuration, however there are other quality Hybrid inverter solutions available – if we don’t offer a specific product/brand, there’s a really good reason for this! Don’t get duped into cheap inverters and installations. Quality and reliability are fundamentally important in this decision. Entry level, cheap inverters simply don’t offer this scalability or reliability.

Option 1: 

  • Install a 5kW Sunsynk inverter with one 3,6kWh Batterich li-ion battery set up as a UPS config initially – this means it will provide back-up for your essential loads (which we split at your DB board) during loadshedding and power outages only. Starting cost is around R72k including professional installation and all the required electrical protection and a COC.
  • If you need a bigger inverter, then go for a Sunsynk 8kW Hybrid Inverter & 7.2kWh Batterich li-Ion battery. Set up as a UPS configuration initially.  Expandable with solar panels and additional batteries. From R115k.


Option 2:

  • Install a 5kW Sunsynk inverter with 7,2kWh Batterich li-ion batteries and a 2.7kW solar array. Starting cost is around R124k including professional installation and all the required electrical protection and COC. This is a full hybrid system that provides for self-generation (electricity savings) and battery back-up.
  • Or a Sunsynk 8kW Hybrid Inverter, 10.8kWh Batterich li-Ion battery & 4.5kW solar array. Full hybrid system for self-generation, electricity savings and battery back-up. From R188k.


Option 3:

  • Install a 5kW hybrid inverter, 10.8kWh Batterich li-ion battery and 5.4kW solar array. Starting cost is R182k including professional installation and all the required electrical protection and COC.
  • Sunsynk 8kW Hybrid Inverter, 14.4kWh Batterich li-Ion battery & 8.1kW solar array. Full hybrid system for self-generation, electricity savings and battery back-up. From R260k.


The beauty with any of these Sunsynk hybrid inverter options is that they are scalable, which means you can add additional panels, batteries and even an additional inverter (Sunsynk is stackable) if your needs drastically changed in time. So you can start with the inverter and battery only, and then add the panels and additional batteries if needed at a later stage.

Starting your journey this way is a massive step towards greater grid-independence and lot more affordable than people realise. If your power requirements are more than this (after putting energy efficiency measures in place), then you can also start with a bigger inverter from the outset and build up in the same way as described above.

With the advances in solar technology and pricing, you can hedge your electricity costs for the next 20-25 years and secure your supply at around 50% of current prices that Eskom can supply it, by making savvy investment decisions today. Any investment you are going to make into alternative energy solutions must take into account the long-term view of where SA’s security of electricity supply and costs are headed – and that’s down the tubes and through the roof respectively.

Avoid at all costs the cheap, quick fixes sold by fly-by-nights who promise you the world with a R10k inverter – if it were that easy and capable of taking you off the grid, everyone would have done it long ago.  There are many unqualified fly-by-nights who have popped up, with even more questionable tech offerings and sub-standard installation quality. You’re going to be installing your solar system on your single most valuable asset and its pivotal to your quality of life, productivity and safety – so be sure to invest in the best quality systems and qualified installers, who are able to stand by the warranties.

 What is an essential vs non-essential load?

Your essential load consists of the appliances and equipment that you want to be able to power up in an outage while non-essential is exactly that – items that are not necessary or vital during an outage.

By splitting your loads, you are able to use your batteries for longer to power up the essential equipment.  Secondly, you also reduce the capital outlay needed on a bigger PV system and battery capacity if you were to try and power up everything in your home/office.

By splitting your essential and non-essential loads at your distribution board, a 5kW Sunsynk inverter with 10.8kWh li-ion battery, 5kW solar panels and a solar geyser will take an average household currently using around 20-25kWh of power per day to around 90% off the grid. No more outrageous electricity bills and you won’t even know when there is load shedding or a power outage.

Essential loads                                         Non-essential loads (heavy loads)

Lights                                                         Anything with an element – geyser / kettle / dishwasher

TV and routers                                         Aircons

Fridge/freezer                                          Heavy machinery and pumps eg pool/borehole pump

Laptops/Computers                               Ovens/Stove (electric)

Electric Fence / Alarm                           Underfloor heating/electric heaters

How long will my battery last? 

The amount and duration of battery back-up is dependent on two factors – the size of the battery bank and the size of the load drawing power from it – in other words how many appliances you have running at the same time, and the total wattage being drawn by these appliances.  It’s one of the reasons why we split essential and non-essential loads, to extend the battery capacity.

For purposes of this exercise, we used one 3.6kWh li-ion battery which allows for an 80% depth of discharge.  This means that once your battery is discharged to having 20% power left, it is automatically disconnected by the inverter to protect your battery’s lifespan. You can of course add additional li-ion batteries if you require more back-up.

Estimated battery running times based on a 3.6 kWh li-ion battery:

2000W = 1.4 hours

1000W = 2.9 Hours

800W = 3.6 Hours

600W = 4.8 Hours

400W = 7.1 Hours

200W = 14.3 Hours

Lithium Ion versus lead acid batteries?

The primary reason to take a step-by-step approach is cost and catering for your changing needs – a good quality, scalable, expandable system that’s going to last you a good 20 years is a key investment – and you want to get it right first time with the right technology and back-up and support.

By adding solar panels later, your system will generate its own electricity and charge your li-ion batteries using the sun’s energy, and not the grid. If you need additional and longer battery back-up to supply more of your home/office electricity requirements, you can also add more Li-ion batteries.

Li-ion batteries have a phenomenal life span – with 6000 cycles at an 80% DOD – that’s a lifespan of 16 years (based on one cycle per day)! You can also expand your li-ion battery bank at a later stage and add more batteries within a certain time frame which you cannot do with outdated and cheaper lead-acid battery technology, which also only allows for a 50% depth of discharge (DOD). Essentially this means you can only use half of your lead-acid battery’s capacity, and the lifespan is 2-3 years at absolute best.

Until recently the majority of homes with energy storage used lead-acid batteries, particularly those that were entirely off-grid, but in the past few years, home energy storage systems using lithium-ion batteries have overtaken the market and provide exceptional performance and lifespan compared with outdated lead acid batteries.

Here’s a rundown on the two technologies:

  • Li-ion batteries do not contain hazardous materials where lead-acid batteries contain lead which is toxic to the environment.  Both battery types are recyclable.
  • Lithium-ion batteries require less energy to keep them charged than lead acid batteries. Lead acid batteries also self-discharge at a higher rate than Lithium-ion.
  • While the initial capital cost for lead-acid batteries is lower than lithium ion batteries, which tends to make them more attractive for homeowners, the downside if that the cycle life of a lead-acid battery is much lower than that of lithium ion. Some last as long as 1,000 cycles while others will only last for 200 charge and discharge cycles.
  • Lithium-ion batteries offer 6 000 cycles and more and will last around 16 years (at one cycle per day) and typically discharge to 20% which means you have at least 80% usable power in your battery.
  • Most lead batteries will typically cycle between 1,000 and 2000 cycles and last about 3-5 years, with a maximum depth of discharge of 50% – essentially meaning that only half of the battery capacity is useable. Over the lifetime of a solar array, a homeowner will have to replace lead-acid batteries numerous times, which makes the total cost of ownership uncompetitive with li-ion.
  • Discharging lead acid batteries too deeply significantly reduces their life expectancy so a bigger capacity battery is required than the actual useable energy it can provide. Lead acid batteries therefore require a lot more space than lithium ion batteries do. Lead acid batteries may produce hydrogen gas so need a well-ventilated situation.
  • Lithium-ion batteries are lighter, far more compact (easier to accommodate) and generally aesthetically more acceptable than lead acid batteries.

The new cost of a Lithium-ion battery system keeps coming down and has already reached a point where cost over time is much less than the rate you can buy power from Eskom or your council.  Longer cycle life, cost per kW and no maintenance costs makes li-ion batteries a far better option to outdated lead acid technology.

Pylontech Li-ion batteries

Why does my choice of inverter matter?

To take a progressive, step-by-step approach to grid independence, you need a scalable, quality solar PV hybrid solution that takes care of your immediate needs for back-up power during load shedding and power failures and allows you to scale up in future to self-generation by adding solar panels.

Not all inverters offer this scalable functionality so it’s essential to work with a renewable energy partner who is experienced in this field, understands and works with your long-term objectives, and really knows their products and pros and cons. Work with a partner with a solid and long-standing track record in the industry, and that will be around to support your system for many years to come.

Anyone who tells you that a R8-10k inverter is good enough to take you towards grid independence is telling you a bare-faced lie. While we understand the appeal of a quick fix solution at a lower cost, the old saying applies, you do get what you pay for. That is very much the case here.

Cheap inverters are very much entry level products, both in terms of quality and functionality, and are simply not geared for a long-term solution towards grid-independence. A low-frequency transformer-based hybrid battery inverter is always a better option, but comes at a higher cost, and for good reason. They are far more robust and dependable and more suitable for reliable daily off-grid energy supply.

To further confuse matters, many of these cheap systems are cloned and repackaged under different brand names and are made by different factories all over China – these again can be of suspect quality, and unlikely to have any aftermarket supplier support and back-up after the sale, and certainly not all the way here in South Africa.

A few very important considerations you need to look at:

  • Is your inverter compliant with the NRS-097 standards (South African grid connection certification)? While this is currently only a requirement in Cape Town and a handful of other councils that have a formal solar PV registration programme, the likelihood that this will roll out to other metros is very high, in which case a non-compliant inverter will not qualify and may not be legally connected to the grid – your money will be wasted.
  • Quality systems will carry a minimum of a 5-year warranty, whereas cheaper systems will offer a one-year warranty – this alone speaks volumes. Many battery manufacturers will also not offer warranties or have very strict connection/usage parameters if connected to these cheaper inverters – not many installers realise this.
  • Most low-cost inverters are uni-directional, so solar power can only address the essential services circuits and savings cannot be made on the high load items not on the backup side of the DB. More sophisticated inverters are bidirectional and allow savings upstream and downstream of the inverter.
  • Low-cost inverters will switch to grid power when the load exceeds the solar generation, and cannot use a combination of grid and solar as do the more sophisticated inverters, so this significantly reduces the savings you will get from your solar system.
  • Remote access to these low-cost inverters can only be achieved with aftermarket devices at additional cost and that are not fully integrated. Be prepared for headaches in this regard.
  • In most instances, the MPPT charge controller is bundled with the low-cost inverter so is less flexible. If either the inverter or charge controller fail, the whole system is down. These systems are also not as easily scalable, if at all.

Why One Energy?

With so many new renewable energy products and suppliers in the market with varying levels of quality, performance, technical expertise and installation experience, its often very difficult to know what the right system is for your needs. Be sure to work with a supplier that complies with safety regulations, that your installation is 100% safe, sound and optimised for your needs, that your products are top tier quality products that provide the savings you expect and will be around for years to come to fulfill on warranties and other servicing requirements.

Check out these important reasons to put One Energy on your list for serious consideration:

  • One Energy was established in 2011 and we have a solid track record and reputation in the industry. We have many years of experience working with the top products and solutions on the market, with an intricate understanding of all the complexities and inter-dependency between components and systems.
  • One Energy has completed over 13 000+ perfect installations as at the end of 2021. As a national franchise group, our clients are assured of having the backing of a national head office and branch network that will be there support you and provide back-up and ongoing maintenance and support. This means you are not at the mercy of solo operators who may not be around in months or years to come to fulfill on servicing, support and warranty requirements on your solar system, which typically has a 20+ year lifespan.
  • Standards and regulations are crucial. We only install tier one products with solid manufacturer warranties and support, and that are aligned and approved to the standards defined by the NRS for embedded generation and thus legally allowed to be connected to the grid. Additionally, we only work with manufacturers who offer in-country support and warranty fulfillment.
  • Another important aspect is the installation of the system. Cutting corners can have dire implications for the safety of the systems and even present a fire hazard. One Energy complies with the highest industry standards in terms of safety and system quality and all our people undergo regular product, technical and safety training.
  • Within our network, we have qualified electricians, PV Green Card installers and plumbers to ensure adherence to standards and best practice. One Energy is also a member of the South African PV Industry Association (SAPVIA), the go-to organisation for all matters relating to the development, regulation and promotion of solar PV in South Africa and sub-Saharan Africa.
  • After sales back-up and support is essential. Dealing with a reputable supplier with a good service ethic that you know is going to be around for years to come and honour warranties is important. Our ethos of perfect installations backed by quality work, service and products means that every one of our clients is a contactable reference. Every installation is tracked with an installation report, photographs and saved to our CRM system for quality checking, warranty management and performance monitoring. 
  • No shooting in the dark – some providers will ask you only for an electricity bill and attempt to provide a PV solution based on this, but the approach is fundamentally flawed and inaccurate since your bill cannot reveal day and night usage, selective loads or peak demands which need to be factored into your PV solution. A thorough load analysis is a must. One Energy can tell you how much your system will generate and what you will save with absolute confidence – because we do the proper groundwork upfront.
  • Our product and technical knowledge is world-class. We believe it’s essential to establish that you are dealing with people who have the required knowledge, expertise, integrity and qualifications. We pride ourselves on our 100% quality guarantee that will see you saving money and the environment from the moment it is up and running, with an expected life span on many products in excess of 25 years.
  • Not all companies offer a range of products. This inevitably results in their pushing the product they stock which may not be right for your needs. At One Energy we never sell a product simply because we want the sale. We always provide the best possible product to suit your needs and we always conduct a thorough needs analysis.
  • We believe in investing the time and effort into educating clients about the finer workings of renewable energy solutions and the benefits both in terms of savings, self-sufficiency and living a greener lifestyle.
  • We are fierce proponents of quality and integrity in the industry, taking a firm stance in educating clients against fly-by-night operators and sub-standard equipment, which does untold damage to the industry and consumer confidence in renewable technologies.
  • One Energy was awarded:
    • Best Renewable Energy Network – South Africa’ in the MEA Markets Business Awards 2020,
    • Most Trusted Renewable Energy Network – South Africa in the MEA Markets Africa Excellence Awards 2021 and,
    • Renewable Energy Network of the Year – South Africa – MEA Business Awards 2021.


Be sure to work with a renewable energy partner that that complies with safety regulations, that your installation is 100% safe, sound and optimised for your long-term needs, that your system is aligned to the NRS 097-2 for embedded generation, and that provides the savings and performance you expect and will be around for years to come to fulfill on warranties and other servicing requirements. Established in 2011 and with over 13000+ perfect installations, we have the track record and experience to walk the journey to grid-independence with you, step-by-step, and get it right first time.