SPOTLIGHT on load-shedding solutions

Load shedding doesn’t have to mean lights out at your home or business. Now there’s a range of effective, and affordable load-shedding solutions to keep you switched on. Whether you require battery backup, renewable energy or a mixture, we have the expertise and products to design a package to suit your unique requirements and your pocket.


In this newsletter, we offer a series of typical domestic and commercial scenarios along with possible product/system solutions and estimated costs.
Please be sure to click on links to read our success stories and get a first-hand report from satisfied clients now enjoying energy security and or off-the-grid urban living.

Please note: All prices are indicative, subject to change and excluding VAT. Delivery and installation incurs an additional cost as indicated.


Scenario 1:

awpower Scenario 1.A: You have a small office or work from home. During load shedding you need to ensure that essential operational equipment continues to function: Laptop or PC, WiFi, LED lamp.
awpower Scenario 1.B: You run a small retail outlet and cannot afford to lose business during load shedding. Your essential operational equipment: POS workstation, printer, cash drawer, WiFi.


Our solution to Scenarios 1.A & 1.B:

With this solution you can continue to run your essentials on battery power during load shedding.

Our Solution #1: Multi-Function Inverter 1.2kW/12V 100Ah Battery Storage

  • Multi-Function Pure Sine Wave Inverter 1.2kW/12V
  • 1 x 12V 100Ah Deep Cycle AGM Battery with fused disconnect
  • Stand-alone or connected to electrical DB
  • DIY battery cabling, extension lead included
  • Battery Box (plastic)
  • Installation not included (option)


Total: R 10,745

Scenario 2:

Scenario 2.A: You run an office with up to 10 laptops, WiFi, Projector, telephone and security system on your essentials circuit.
awpower Scenario 2.B: Your retail business essentials are a PC/POS workstation, slip printer, pay-point, WiFi and LED lights.
awpower Scenario 2.C: You wish to maintain power to essentials in your home such as Fridge, PC, TV & DVD, LED light circuit and alarm.

Our solution to Scenarios 2.A, 2.B & 2C:

With this solution you can continue to run your essentials on battery power during load shedding.

Our solution #2: Multi-Function Inverter 5kW/48V 100Ah Battery Storage

  • Multi-Function Pure Sine Wave Inverter 5kW/48V
  • 4 x 12V 100Ah Deep Cycle AGM Batteries, expandable to 240Ah
  • Custom Stand-alone Electrical sub-DB or attached directly to DB
  • Battery Boxes (plastic)
Total: R 32,485
  • Upgrade to Industrial quality battery enclosures: + R949
  • Upgrade to 240Ah AGM/Gel Hybrid Batteries (4x): + R19,950

Estimated cost of delivery & installation: R 3,995

Click on the following links to read more about relevant AWPower Success Stories:

Scenario 3:

awpower Scenario 3: Get off the grid – the pocket-friendly option

You wish to get off the grid as far as possible, without breaking the bank, and use renewable energy to power your medium-size house, with single phase supply, geyser, pool pump and borehole.

Our Solution #3: Off-Grid Inverter 6kW/11.5kWh AGM/Gel Batteries/3.3kWp PV
  • Load shifting managed with Geyserwise controller, geyser element reduced to 2kW
  • Modular and highly expandable to full off-grid
  • You can expect to recoup your cost in 5 to 6 years
  • City of Cape Town registration and certification included
  • MLT Oasis 6kW/48V Off-Grid Inverter (single-phase)
  • 3.3kWp Solar PV modules (incl. roof mounting structures)
  • 3.2kW MPPT Charge Controller
  • 4 x 12V 240Ah AGM/Gel batteries (2,500 Cycles), expandable to Li-Ion
  • Including Switchgear, cabling & 40m solar wiring
Total from: R 139,995
Estimated installation cost: R 18,987


Click on the following links to read more about relevant AWPower Success Stories:

Scenario 4:

awpower Office Block 650m2 with 4 office units, each with aircon, 10 laptops, WiFi, telephone, alarm, projector, 3-phase electrical supply and communal geyser
Our Solution #4:

Grid-tied solar inverter per phase (3 x 4.6kW with 15kWp PV) for main building + 5kW/48V Multi-Function Inverter with 100Ah battery storage per office unit.


  • Grid-tied inverter for main building solar generation (energy savings) plus battery backup system for individual office units (energy security). Battery backup upgradeable to full off-grid battery inverter with PV (like solution #3)
  • 13.8kW Grid-tied Solar PV System for complete building
  • Multi-Function Pure Sine Wave Battery Backup Inverter 5kW/48V per office unit

Grid-tied system:

  • 15kWp PV array
  • 3 x Solis Direct Grid Tied Inverter – 4G Single-Phase Dual MPPT 4.6kW
  • Including switchgear
  • Payback between 3 to 4 years
  • Savings could potentially exceed monthly premiums
  • Professional Engineer Signoffs and CoCT registration included
Total from: R 230,000
Estimated installation cost: R 26,000

Battery backup system per Office Unit:

  • Multi-Function Pure Sine Wave Inverter 5kW/48V
  • 4 x 12V 100Ah Deep Cycle AGM Batteries, expandable to 240Ah
  • Custom Stand-alone Electrical sub-DB or directly connected to DB
  • Battery Boxes (plastic)
Total from: R 33,000

Upgrade to Industrial quality battery enclosures …………………….. + R949
Upgrade to 240Ah AGM/Gel Hybrid Batteries (4x) …………………… + R20,500
Estimated delivery & installation ……………………………………………… R 3,995


FAQ: How many hours of power can a multi-function inverter with battery storage provide?

This depends on the load. By reducing your load during a power outage, the batteries will last longer. For example, using 1kW of power on a 1kWh system will deplete the batteries in an hour, but by turning off non-essential equipment and reducing the load to 500W the system will last 2 hours. Typically, battery back-up systems should be sized to combat load shedding which occurs in up to 2.5-hour segments and up to 3 times a day (Stage 4). The battery back-up system should be sized sufficiently to have time to charge fully between load shedding periods.

FAQ: Does the battery back-up system automatically switch to battery power when the grid falls away and does it charge the depleted batteries when the grid returns?

Yes, the system will seamlessly switch to battery back-up when the grid falls away and automatically use the grid power as soon as it becomes available to recharge the depleted batteries. There is no down-time for your essential equipment when load shedding kicks in.

FAQ: What are the three typical configurations for RESIDENTIAL AND COMMERCIAL PV systems?

Grid-Tied Feed-In PV Systems. These systems have PV (photovoltaic) panels connected directly to an inverter. The electricity generated is used locally on the property. Excess generated electricity is fed back into the electricity grid. A grid-tied solar power system is required by law to have an anti-islanding function, which senses when a power outage occurs and shuts itself off. Such systems have no batteries.

Grid-tied PV Systems with Reverse Power Blocking provide electricity to the property when there is a demand for it, but blocks any excess electricity generated from feeding back into the grid. When insufficient solar energy is available, electricity drawn from the mains grid can make up the shortfall. These systems also have no batteries. They currently offer the best return on investment.

Standalone (off-grid) PV Systems usually have batteries and a charge controller. The PV (photovoltaic) solar system produces electrical power to power the property as well as charge banks of batteries during the day for use at night when the sun’s energy is unavailable. A stand-alone small-scale PV system employs rechargeable batteries to store the electrical energy supplied by a PV panels or array. This offers the best solution for energy security and grid independence.

FAQ: On a rainy day, will my off-the-grid solar powered system still power my house or office?

During a rainy or cloudy day, the generation capacity of PV modules is reduced to as far as 30%, hence more PV modules would be installed to counter regular adverse weather conditions. The battery power would kick in to supply power during such conditions, but it is normally more economical to increase the installed capacity of solar modules.

FAQ: How often will my system require maintenance?

PV modules should be cleaned once a year, good quality Inverters may require servicing every five years. These days batteries are generally sealed and hence maintenance free. However, the inverter may require adjustment for battery cycling to ensure efficient operation during the rainy season.

FAQ: How long do the batteries last?

This depends on the battery:

High durability deep cycle flooded lead-acid batteries have a discharge efficiency of approximately 60% with typical cycle life of 1,600 cycles. With a depth of discharge (DoD) of 50% and may need to be replaced within 3 to 4 years.

Deep Cycle AGM/Gel Hybrid batteries have an estimated cycle life of 2,500 cycles, with a depth of discharge (DoD) of 50%, lasting up to 7 years. These batteries are sealed and thus are virtually maintenance free.

Lithium-ion batteries have a discharge efficiency of approximately 96% with a cycle life of 7000 cycles and are guaranteed for 10 years. These are virtually maintenance free.

FAQ: Can I run large appliances like my dishwasher, washing machine, vacuum cleaner and pool pump at the same time if I’m using solar power?

It depends on the capacity of the inverter, state of charge of the batteries and the solar PV generation capacity. If a 6kW inverter with matching batteries and solar PV is installed, the system may cope with the above load from about 10:00 to 15:00, but earlier or later, or at night, such a load will put undue pressure on the battery bank and may result in the system switching over to the grid to feed the load and also to charge the batteries. However, if the load in above example exceeds 6kW (exceeding peak load – see below) for more than 30 seconds, the system will shut down to protect itself.

Living with renewable energy does require an adjustment in both attitude and the way you operate in either your household or office. With a PV system, one soon learns to productively extract as much energy during the day while the sun is bright and shining, but when the sun goes down, to reduce demand, commonly referred to as the load. When sizing a PV system for the requirements of the household or business, the following factors are taken into consideration: What is the peak load, and could this be reduced by load shifting? Load shifting is accomplished when the high-energy devices and appliances (geysers, pool pumps, dishwashers, micro-wave ovens, heaters, air-conditioners, etc.) are prevented from being used simultaneously by either installing time switches or by implementing changes in the daily routine of the household, for example never run the dishwasher when the sun is not shining. When running solar it is important to know that the inverted power has a maximum capacity, commonly referred to as the kW rating, and that the highest demand from the load at any point (peak load) should not be allowed to exceed the installed kW rating of the inverted power for an extended period.

FAQ: Can a Stand-Alone (off grid) PV System support a conventional household geyser?

Yes, provided that the standard 3kW geyser element is replaced by either a 1.5kW or 2kW element, which may take a bit longer to heat up, but drastically reduces the load in support of a lower capacity inverter. Naturally such geysers should be controlled by time switches to ensure effective load shifting. The Geyserwise intelligent controller is highly effective for managing geyser power draws.

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