Power Solutions – Frequently Asked Questions

We recently released our latest Power Solutions Information brochure and thought the Frequently Asked Questions would be a valuable addition to our blog.

Let’s get right into it:

Q:  What’s going on with all this load shedding?

A:  Eskom’s aging fleet of power stations and lack of regular maintenance has led to an unprecedented amount of breakdowns.

This, together with Eskom’s delayed response of adding additional generation capacity, has led to the worst Energy Availability in South Africa’s history. To put this into perspective, please review the 2016 to 2022 Energy Availability Factor graph below, which shows how much of Eskom’s generational supply is operational:

Eskom Generational Supply | 2016-2022
Eskom Generational Supply | 2016-2022

Q:  What are my options?

A:   You can choose to do nothing, or you can escape the power interruptions by investing in a Battery Backup Solution, with Solar as an optional extra.

Q:  What is kW?

A:   It’s shorthand for Kilowatt, or 1000 watts, which is a measure of electricity usage.

Q:  What is kWh?

A:   It’s shorthand for Kilowatt Hour and denotes the usage of electricity over time. Sometimes people refer to these as “units” of electricity. As an example, if my Pool Pump uses 1100 watts (1.1kW) of electricity, and I run it for 7 hours a day, it uses 7.7kWh of electricity. It is calculated by simply multiplying out the electricity usage and time: 1.1kW x 7h = 7.7kWh.

Q:  How much electricity do my appliances use?

A:  It depends. As a generalization, we will list some appliances with their individual power rating:

  • Below 1kW:  TV, Fridge, Freezer, Fan, General House Lights
  • 1kW to 2kW:  Air Conditioner, Heat Pump, Food Processor / Blender, Toaster, Coffee Machine / Nespresso
  • Around 2kW:  Air Fryer, Microwave, Kettle, Iron, Hair Dryer, Washing Machine, Tumble Dryer, Vacuum Cleaner, Electrical Heater
  • Over 3kW:  Geyser, Oven

Q:  How much electricity does a typical house use?

A:  From our experience, it varies quite dramatically. In a “normal” single-phase home, we’ve seen daily use of 20kWh to 80kWh, with the average being around 30kWh.  1kWh tranlates to 1 Unit on your electrical meter/bill. To find out your usage, please refer to your Municipal Account or your Prepaid meter purchases.

Q:  How can I lower my Electricity Usage?

A:  There are too many things to list, but the biggest is changing your Geyer to a Heatpump or Solar Heating.  Please note that it’s always less expensive to invest in ways to reduce your electricity usage compared to investing in additional Solar/Batteries.

Q:  What warranty / hardware lifecycles can I expect?


  • Inverter – SunSynk and Victron both carry a 5 year warranty
  • Battery – SunSynk provides 6000 cycles at 80% DoD (Depth of Discharge) whereas FreedomWon provides 5500 cycles at 80% DoD
  • Solar Panels – They have 80% performance/yield warranty after 25 years

Q:  What is Off Grid?

A:  An Off Grid system implies that you’re not connected to Eskom/City of Cape Town’s electricity Grid. Practically, it just means that you need to supplement your Solar Array with alternative means of generation for rainy days – such as a Generator and/or Wind Turbine. Having said that, the cost of adding alternative generation is generally not worth it, and one can rather easily reduce your reliance on the electricity grid by 95% and be totally unaffected by any form of grid outage.

Electricity Usage Graph
Statistics from one of our clients showing a 5% Grid Electricity usage – Courtesy of Victron Remote Management Portal

Q:  What size inverter do I need?

A:   It depends. If you’d like a small system to only run the low utilization items such as lights, internet, television and fridges/freezers, then the 3kW options with a single 5kWh battery is enough for your needs to last you through Stage 8 Load Shedding. If you can’t live without coffee for 2-4 hours, then a 5kW solution should be considered, and if you can’t live without air conditioning, then you should look at the 8kW option.

Q:  Why do you only sell Lithium Batteries?

A:  Lead Acid type batteries (Deep Cycle, GEL, AGM) are obsolete and have a very limited cycle (one discharge and charge) life, typically no more than 1300 cycles. To get to the maximum number of cycles, you must also conform to their limitations:

  1. You keep them at a mild temperature, typically 25 degrees centigrade.
  2. You must charge and discharge the batteries at the recommended ‘C’ rating, typically C20. This means that you can get the full rated capacity out of the battery over 20 hours.
  3. You can only discharge 50% capacity (Also know as DOD, Depth of Discharge).

Doing all these things, will ensure the longevity of your Lead Acid battery.

By contrast, Lithium batteries typically have a cycle life of around 5000-6000 cycles, rated to charge and discharge their entire capacity in 1 hour, can discharge all the way down to 0% and not nearly as sensitive to temperature fluctuations. Not to mention that they are more energy dense (so they take up less space) and come in a more aesthetically pleasing form factor.

Q:  Don’t Lithium Batteries catch fire?

A:   There are various chemistries of lithium batteries. The one we use, LifePO4, is the safest type of Lithium batteries and will not overheat or result in thermal runaway.

Q:  Why Victron?

A:   Victron is a Dutch brand founded 50 years ago. In South Africa, they have been the market leader for decades and cannot be beaten on reliability, functionality, and support.

Their architecture is modular, meaning it’s easy to add to the solution down the line. Their remote web-based system management and reporting solution allow for monitoring, reporting and configuration anywhere in the world.

If you want the best, you want a Victron.

Q:  Why SunSynk?

A:   A Chinese brand that seemingly took South Africa by storm in the last few years! They stand out from the generically Voltronics Power rebrands by providing just the right number of features and quality, while also sporting a 5-year warranty.

If you can’t have Victron, get a SunSynk!

Q:  Must my system be registered with the City of Cape Town or Eskom?

A:   Battery Backup Solutions do not need to be registered, but Solar Solutions do.

Q:   Is an Electrical Certificate of Compliance (COC) required?

A:   Strictly speaking, a COC is not required when installing a Battery Backup Solution. For Solar Solutions – it is however required as part of the Solar registration process. We supply COCs with every installation, Battery Backup and Solar, to certify that our installations comply with all requirements, and to provide peace of mind.

Q:  What is SSEG and how does it work?

A:  SSEG is short for Small Scale Embedded Generation and is what the City of Cape Town defines adding a Solar Array as. The process for registering your Solar Solution with them works as follows:

  1. We work out a technical solution, fill out their application form and submit it to them.
  2. They approve the installation.
  3. We install the solution and get an ECSA qualified engineer to sign it off and submit additional documentation thereafter.
  4. They then provide a letter of registration.
  5. Finally, we can take the Solar Solution live.

Q:  Do I require Solar?

A:  If you’d like to generate electricity to offset the ever-rising cost of electricity from Eskom / City of Cape Town, then yes.

Q:  What size Solar Array do I require?

A:  It depends. If you’re looking to offset some of your daytime (daylight hours) electricity usage, then a small Solar Array will most likely work best. If you are looking for maximum savings, then you’ll need to invest in a large Solar Array with lots of batteries.

An example of a North Facing 3kW Solar Array Average Yield during the day
An example of a North Facing 3kW Solar Array Average Yield during the day

Q:  Why does my Standalone Grid Tied Solar Solution switch off when there is a Grid Outage such as Load Shedding?

A:   Grid Tied Solar Solutions need to shut down in the event of a Grid Outages in order for it to not push electricity back into the grid and potentially shock anybody working on the Electricity Line. This is a safety feature and a requirement for connected to the Grid. If you’d like a Solar Solution that does not switch off during a Grid Outage, we suggest you look at the Battery Backup Solutions with Solar Add On.

Q:  Why are batteries so important for Solar?

A:   If you would like to maximize the potential saving from your Solar Array, then you will need a way to store the generated energy for later use (at night when the sun isn’t shining). At that time, your inverter will then discharge your batteries until a specific Depth of Discharge is reached, leaving enough reserve capacity to cater for up to Stage 8 Load shedding

Q:  Why is my Solar Yield so low?

A:  This can be due to several reasons:

  • A Solar Panels power rating is determined in STC (Standard Test Conditions). Unfortunately, this is done in a controlled lab environment, and not indicative of real-world conditions. Always expect a lower yield than your Solar Array rating.
  • In Cape Town, our Summer to Winter Solar Yield varies considerably. Refer to the image below the “What size Solar Array do I require” question to provide insight into Summer vs Winter Yields.
  • Your Solar Array is potential energy. This means that if it’s not used, it’s lost. As an example, if my 3kW Solar Array is generating 3kW power, but my House is only consuming 1kW of power, the other 2kW is not generated. It’s got nowhere to go! If I had additional batteries, it could have been used to charge my batteries.
  • Your Solar Array might be excessively dirty, or partially shaded by a new obstruction (typically a tree).

Q:  Which Way should my Solar Array face?

A:  The short answer is anywhere except South! We favour East and West layouts over the traditional “just point it North” configuration, because it spreads the Solar Yield out over a longer period, therefore leading to longer utilization of the available Solar Energy.

Q:  What Maintenance is required for my Solar Array?

A:   No maintenance is required, but we recommend that the solar array be cleaned every year with cold water and a sponge. Sunlight liquid is also fine. Please don’t use a high pressure water system.

Q:  Do you offer financing?

A:  We do not, but banks are much more informed about solar solutions and could most probably assist. We suggest you get in contact with your banker to enquire.

Q:  Can I sell my excess electricity back to the City of Cape Town?

A:  Yes, you may! The City of Cape Town has made it more accessible for you to feed back into the grid and will refund you 78.98c per kWh. There is an additional incentive amount of 25c per kWh until 30 June 2025.

Please Note:

  • The daily administrative fee required for the privilege of feeding back into the electricity grid was dropped a few years ago.
  • You must stipulate at the time of Registration whether you’d like to feed back into the electricity grid.
  • You must be a net electricity consumer, which means you must use more electricity than you export to the electricity grid in a 12-month period. *
  • There is an additional cost of R 12 850 inc. VAT, payable to the City of Cape Town, to replace your pre-paid meter to the newer AMI version, which can measure electricity flow in both directions.

* With Mayor Lewis’s announcement of the Cash for Power incentive in January 2023, the requirement to be a net consumer will fall away. However, this initiative will only be implemented for residential customers at the end of the year, and therefore this requirement still stands for now.

Q:  How long is my Return on Investment for my Solar solution?

A:  It’s a simple calculation we provide as part of our final quotation. Typically it’s around 7 years.

In this calculation we consider:

  • Existing electricity prices (R2.63 for the first 600 kWh, R3.63 for each unit thereafter)
  • Year on year price increases in electricity (18.65% for 2023 and 12.74% for 2024 for Eskom)
  • Your average electricity usage
  • Projected Solar Yield savings

Q:  How long is my Return on Investment for my Battery Backup solution?

A:   A Battery Backup Solution is purely a Commidity for convenience. If you’d like a return on investment, your should invest in solar.

Q:  What additional costs can I expect?

A:   Once we’ve agreed on your solution, a final quote will be emailed to you – the pricing on this quote will be the final cost. Should there be any unforeseen complications with your electrical DB we will bring this to your attention, including any additional costs that may be required to resolve.

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