Sorting out your own home power system – and what it costs

As beleaguered South Africans battle to organise their schedules around Eskom’s 6-hourly load-shedding programme, most have realised that waiting in the candlelight for the lights to come on no longer works. They have to make alternative arrangements – but where to start? MyBroadband offers some suggestions. – Sandra Laurence

Backup power systems to get through Stage 6 load-shedding

By Myles Illidge

South Africa has been plunged into stage 6 load-shedding from 16:00 on Tuesday, 28 June 2022, increasing the frequency and length of rotational power cuts.

Eskom chief operating officer Jan Oberholzer said they did not decide to escalate load-shedding lightly, as stage 6 is a step-change from the lower stages of load-shedding.

Stage 6 load-shedding doubles the frequency of Stage 3 power cuts, meaning power is cut to areas for 36 hours over four days — an average of nine hours each day.

When the country is under stage 6 load-shedding, the rotational power cuts are implemented in bouts of two and four hours, with an additional 30 minutes to restore power.

The “uptime” you get between bouts of load-shedding typically lasts between three-and-a-half and five-and-a-half hours at stage 6.

MyBroadband considered what kind of battery backup system you would require to power some basic electrical equipment through four-and-a-half-hour load-shedding sessions.

Our requirements were to power a Wi-Fi router, TV, DStv decoder or streaming stick, and a couple of LED lights.

According to Energy Use Calculator, the average Wi-Fi router draws 6W. This works out to 27Wh over four-and-a-half hours.

The average 55-inch TV draws less than 60W of electricity or 270Wh over four-and-a-half hours.

LED lights are known for using less power than other light bulbs. We selected 5W-rated LED lights for our analysis.

Over four-and-a-half hours, a 5W bulb will use 22.5Wh. Two bulbs will use 45Wh.

The power consumption of DStv decoders varies depending on the model. A DStv Explora has a maximum power consumption of 45W, which means it will use 202.5Wh over four hours.

Streaming sticks use less electricity, often using a standard 5W power brick.

The average power usage of some basic electrical equipment is summarised then the table below.

Four-hour backup solutions

During stage 6 load-shedding, power can be cut for 4.5 hours at a time, with around 3.5 to 5.5 hours of “uptime” between bouts to recharge batteries.

While uninterrupted power supplies (UPSes) are often sufficient to power a few pieces of equipment simultaneously during 2.5 outages, most can’t last through longer power cuts.

It is also important to note that most UPSes — and many battery backup solutions — use lead-acid batteries that are not designed to discharge below 50%.

The watt-hour capacity of a backup system should therefore be at least double that of the total consumption of the electrical equipment you want to run through load-shedding.

Several battery backup systems that could power your electrical equipment through 4.5-hour bouts of load-shedding are listed below. Your needs will vary based on the power consumption of your equipment.

Mecer Home Office Inverter Trolley UPS — R7,399

Mecer Trolley Inverter (720W) — R7,699

Solarwize Smart power backup trolley — R9,100

Gentech 800 Watt Hybrid Inverter System — R9,495

Kapa Energie-1000 Pure Sine-Wave UPS Inverter (1,000W) — R11,999

Power4Less Mobi Volt 1.2kWh sinewave inverter backup — R14,999

PowerOak EB150 1,000W Inverter with  1.5kWh Lithium-Ion Battery — R20,999

EcoFlow DELTA 1260Wh Portable Power Station — R22,589

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