THREE MAIN OPTIONS
If you need many of your lights and appliances to stay on during loadshedding, you basically have a choice between a generator and an uninterrupted power supply (UPS). If you want to invest in greater energy security for the future, you could also opt for solar-hybrid systems which will make you less dependent on Eishkom – and lead to big savings in the long run.
A generator uses petrol or diesel, while a UPS is essentially a big battery. Both have pros and cons.
1 GENERATORS
If you want to keep most of your household appliances on, a petrol or diesel generator of 6 400 watts (8 kilovolt-ampere or kVA) is a good choice, says Alwyn Coetsee, managing director of Turner Morris, a company that supplies equipment to the construction and agricultural industries and specialises in power-supply solutions.
“It’s big enough to cover most of a house
Things to be aware of
“A standard generator is noisy. Some people don’t like it or they live in a complex or on an estate, many of which have restrictions on decibel levels,” Coetsee says. “But you do get quiet generators now, purpose-made in a special container with enough air flow to keep it cool – you can barely hear it from 6m away.”
Generators also release pollutants, so never run a generator inside the home or even in the garage – the fumes can cause carbon-monoxide poisoning.
Never refuel a generator while it’s running, Coetsee warns. “If petrol or diesel spill on a spark plug, the whole thing could go up in flames.”
A generator must run outside but you can erect a shelter to protect it from the elements.
Safety first
Some generators can be connected to your hold’s electricity needs, excluding the geyser and the swimming pool pump,” Coetsee says.
A 6 400W generator should be able to power the moderate use of a standard stove too, he adds.
If you mainly want to keep your lights and electronic equipment such as TVs, cellphones and computers on during outages, a 2 000W (2,5kVA) generator should suffice. main power board but be sure to have a certified electrician do this for you. Insist on an electrical compliance certificate, Coetsee says. “Illegally connected generators can lead to malfunction which can cause a fire and affect home-insurance claims.”
With loadshedding there’s been a dramatic increase in power-related products on the market but these can’t necessarily be legally connected to power boards. Use suppliers with a proven track record who’ll be able to supply parts for years to come. A generator can last up to 20 years if you look after it well. “Ensure generators used during loadshedding have an AVR – automatic voltage regulator. If they don’t, they can irreparably damage electronics such as your TV or computer.”
ESTIMATED COST
6 400W – R8 000 to R10 000 2 000W – R3 500 to R4 500
2 UPS SYSTEMS
A UPS consists of a number of rechargeable batteries (a battery bank), controller and inverter, all mounted together in a box. You can ask an electrician to connect your UPS directly to your main power board so it automatically switches on during loadshedding, and off again when the lights come back on.
Alternatively, you can use an extension cord to connect to something specific you want to stay on during loadshedding, such as your fridge. Or you can simply plug a device into the UPS.
The duration of the UPS’ operation and how long it takes to charge depends on the type of UPS, how many batteries it contains
Things to be aware of
A UPS of 1 600W (2kVA) is sufficient if you want to power only lights and electronics such as TVs. This should have a large enough battery bank to last for a loadshedding session.
If you want a bigger UPS that can potentially run fridges and the rest of the household – excluding the geyser and stove – you’ll need a UPS of about and how many devices you connect to it at one time.
“Your running time is important in a UPS system and that’s determined by the size of the battery bank,” Coetsee says.
“The running time will be stated in the specifications. Usually it’ll say if you use 80% of the UPS’ capacity it’ll run for a specified length of time. This also determines the price.”
So it’s not ideal to have a UPS with a small battery bank and a large power output.
“A lot of people will offer you a cheaper UPS but its battery bank won’t be sufficient to run for a long time. So the 4 800W (6kVA). A UPS of 8 000W (10kVA) is ideal for a larger home and could for example also power a stove if need be.
Pros and cons
A UPS is pricey but its benefit is there’s no noise and no changeover – when loadshedding kicks in, there’s no delay in the power supply. But the battery life is sometimes limited, Coetsee warns. “Batteries often don’t last longer than about five years before you need to replace it.”
ESTIMATED COST
1 600W – R15 000 to R20 000 4 800W – R60 000 to R70 000 8 000W – R100 000
3 SOLAR POWER HYBRID SYSTEMS
This is the most expensive of the three options to set up initially – but in the long-term it definitely makes sense, Coetsee says.
“A solar power hybrid system includes a battery power bank and works in conjunction with the Eskom grid,” he explains.
“While the sun is shining it generates power – you use solar power mainly and less Eskom power. When there’s no sun, it switches over to Eskom power; and when there’s loadshedding, it switches over to batteries.
“If you install a 4 000W (5kVA) solar power hybrid system, you’ll be able to run more or less everything in your house on it, apart from the geyser and the stove. With a 12 000W (15kVA) system, you should be able to run everything in the average household.”
Advantages
These systems don’t come cheap, “but you can save up to 80% of your electricity bill, so you’ll pay it off within two or three years,” Coetsee says.
And if you have a business, you can also claim back about a third of the outlay from tax.
South Africa on average gets more than 2 500 hours of sunlight a year, double the solar radiation of Europe, for example. This makes our country the perfect place to install solar panels at homes, says Angela Lee-Wright of online eco store sustainable. co.za.
ESTIMATED COST
4 000W – R85 000 12 000W – R200 000