Although generators are cheaper than an equivalent battery backup, the cost to run them can be quite high depending on load-shedding intensity.
MyBroadband determined how much smaller generators — capable of running your internet, computer, TV, and a few other appliances — cost to run at varying frequencies of stage 2 and 4 load-shedding.
For our calculations, we used varying periods of load-shedding for both Stage 2 and 4 power cuts.
The periods we used were:
- 60 days — 180 hours at Stage 2, or 360 hours at Stage 4;
- 120 days — 360 hours at Stage 2, or 720 hours at Stage 4; and
- 180 days — 540 hours at Stage 2, or 1,080 hours at Stage 4.
A breakdown of the cost per hour to run a range of small petrol generators is provided in the table below. We used June’s unleaded 93 fuel price of R23.94 per litre.
The table also includes the expected cost per bout of stage 2 and stage 4 load-shedding, and the generator’s price.
|Generator fuel costs|
|Generator||Price||Consumption||Cost per hour||Cost: Stage 2||Cost: Stage 4|
|Ryobi 1200W 4-Stroke Pull-Start Generator||R3,999||1.07L/h||R25.62||R64.05||R115.29|
|MAC AFRIC 2.8 kVA (2 KW) Standby Petrol Generator||R4,495||0.82L/h||R19.63||R49.08||R88.34|
|Ryobi 1200W Inverter Generator Open Frame RG-1280I||R4,999||0.83L/h||R19.87||R49.68||R89.42|
|MAC AFRIC Inverter Generator (1,800W)||R7,250||1.00L/h||R23.94||R59.85||R107.73|
The most fuel-efficient generator compared is Mac Afric’s 2.8kVA standby petrol generator at 0.82 litres per hour. It is available from Adendorff Machinery Mart for R4,495.
We also included two inverter generators in the comparison, as they might be more appealing to those looking for a quiet backup power solution.
The inverter generators often carry heftier price tags. In the case of Mac Afric’s 1,800W inverter generator, it uses more fuel too.
Notably, Ryobi’s 1,200W inverter generator is more fuel-efficient than its 1,200W 4-stroke petrol generator.
The table below provides the expected cost to run these generators for one year at various intensities of stage 2 and stage 4 load-shedding. Totals include the cost of buying each generator.
|Generator costs over time|
|Generator||Stage 2 load-shedding intensity||Total cost (incl. generator price)||Stage 4 load-shedding intensity||Total cost (incl. generator price)|
|Ryobi 1200W 4-Stroke Pull-Start Generator||60 days / 180 hours||R8,610.60||60 days / 360 hours||R13,222.20|
|120 days / 360 hours||R13,222.20||120 days / 720 hours||R22,445.40|
|180 days / 540 hours||R17,833.80||180 days / 1,080 hours||R31,668.60|
|MAC AFRIC 2.8 kVA (2 KW) Standby Petrol Generator||60 days / 180 hours||R8,028.40||60 days / 360 hours||R11,561.80|
|120 days / 360 hours||R11,561.80||120 days / 720 hours||R18,628.60|
|180 days / 540 hours||R15,095.20||180 days / 1,080 hours||R25,695.40|
|Ryobi 1200W Inverter Generator Open Frame RG-1280I||60 days / 180 hours||R8,575.60||60 days / 360 hours||R12,152.20|
|120 days / 360 hours||R12,152.20||120 days / 720 hours||R19,305.40|
|180 days / 540 hours||R15,728.80||180 days / 1,080 hours||R26,458.60|
|MAC AFRIC Inverter Generator (1,800W)||60 days / 180 hours||R11,559.20||60 days / 360 hours||R15,868.40|
|120 days / 360 hours||R15,868.40||120 days / 720 hours||R24,486.80|
|180 days / 540 hours||R20,177.60||180 days / 1,080 hours||R33,105.20|
Certain generators are relatively cost-effective compared to battery backup systems when Eskom’s load-shedding intensity is low at Stage 2. Costs, including the generator’s price and fuel consumption, range from R8,028 to R11,559.
Comparatively, a small backup battery system such as the 1.4 kWh RCT Compact Lithium Back-Up Kit, costs around R12,000.
Battery system prices vary based on the type and capacity of the system — for example, Omnipower’s 2kW Long Backup Power System Kit costs around R21,000.
As load-shedding intensifies, generators can become much more costly than battery backups.
At 60 days of Stage 4 load-shedding, small generator costs equal or exceed the price of equivalent battery backup systems.
In the worst-case scenario, these generators cost between R25,695 and R33,105 to buy and run for 180 days of Stage 4 load-shedding.
It is important to note that batteries for backup systems must be replaced after approximately five years of use.
However, considering that the most fuel-efficient generator in this comparison can cost around R40,000 to run for five years, at stage 2 load-shedding and including the generator’s price, it is safe to say that battery backup systems are more cost-effective in the long run.