Options for back-up power
A NATIONAL state of disaster was recently declared and gazetted to deal with the energy crisis in South Africa.
While delivering the State of the Nation Address, President Cyril Ramaphosa said the declaration would enable the government to intervene to ensure the energy crisis was given the focus it deserved.
Ramaphosa said load shedding could not be solved without enlisting other ways of generating energy. This, he said, included gas, nuclear and renewable energy.
A minister of electricity has been appointed and would assume full responsibility for overseeing all aspects of the electricity crisis response.
But it could take South Africa 12 to 18 months to improve energy provision and end power cuts, Enoch Godongwana, the Minister of Finance, said recently.
In his recent Budget speech, he announced a rebate system for South Africans who wish to install rooftop solar panels. He said from March 1, 2023, individuals could claim a rebate of 25% of the cost of the panels, up to a maximum of R15 000.
This is expected to help South Africans who are looking into alternate power solutions.
Power experts, meanwhile, provided several options for back-up electricity. These include:
◆ Portable power stations: A batteryoperated device that can be recharged. It is a plug-and-play system that can keep essential appliances and devices running.
◆ Inverter power systems: Works by storing energy in batteries and converting it into electricity when needed.
◆ Uninterruptible power supplies: Provides a back-up source of power when the main power supply is interrupted.
◆ Portable generators: Works by converting fuel-based power into electric power.
◆ Solar panels: A device that collects sunlight and converts it into electric current.
◆ Hybrid system: Combines solar panels, batteries and an inverter to provide a renewable source of power.
Reston Matchado is a private electrical installation technician who specialises in alternate power solutions.
He said for those looking for an affordable solution, a portable power station was cost-effective and priced at around R2000 to R10000.
“This can be used to plug in your fan on hot summer days, your TV, wi-fi and charging cables,” said Matchado.
He said this, in conjunction with a gas stove and battery-powered lights, would lessen the impact of load shedding.
“The cost of a gas stove in Durban can vary. It depends on factors such as brand, size and features. On average, you can expect to spend anywhere from a few thousand rand to tens of thousands of rand for a high-end model.”
The price of battery-operated lights can start from R150 upwards.
Matchado said choosing solar power was a more expensive option. It requires an inverter, solar panels and a lithium battery.
“For solar power energy, you need solar power panels. Normally, one would need at least five panels of 500 watts each. Each panel costs on average R3 500.
“For this, you would need a separate DB (distribution board). It must be placed close to your original. The cheapest option for solar power can be R55 000, but this is with a cheap non-lithium battery that is not of good quality. With a good lithium battery, it can cost up to R100000.”
Matchado advised against generators.
“Generators are quite a nuisance. You need to put it on and off unless you get an automatic one, which is incredibly expensive. Then you need to fill it with oil and fuel. It's like a car. It's not worth it.”
He said the inverter system, which could cost up to R90000, was a good investment and lasted at least 15 years.
Builders, a home improvement supplier, provided a list of power solutions on its website.
They said there were benefits to opting for power inverters because they were silent, overload and short-circuit protected, portable, and provided automatic mains to battery switch over.
Mpeyake Khosa, a Builders SA Electric and Alternate Power Buyer, said when installing solar power, one could start small and increase the storage at a later stage.
“An average home in South Africa would need a 5 kilowatt (kW) unit to run essential appliances. (One kilowatt is equivalent to 1000 watts). To make the solution even more economical, it is recommended that you install a gas stove, a gas geyser or a heat pump and emergency lights to not overload/use the unit.
“You can start small with a 3kW capacity and expand on storage. The cost of a kW complete solar solution can vary between R100000 and R200000, depending on the number of panels required, quality, and brand of inverter and batteries. There should be a trade-off to what you currently spend on power to finance the unit over a number of years (5 years).”
He said there were also new portable power solutions available.
“These come with advanced battery capacity, fast charging ability and strength to run some high consumption appliances like fridges, microwaves, coffee machines and so on.
“An example of such a portable machine is the Ecoflow River Pro, which can attach a battery for extra capacity, and Ecoflow Delta, which can be paired in series to add more capacity.”
Ross Müller, the technical director for the Grid Freedom Group (solar and water specialists), provided four non-solar options for a back-up electrical system from the least to the most expensive.
1. A 1 kW battery back-up: This is a plug-and-play system that would need to be positioned next to a TV to run a lamp, wi-fi and sound system. “This is a 1 000W Pure Sine Wave Inverter with a built-in 100Ah (100 amperes an hour) gel battery with a 1-year warranty. This costs R8 625.”
2. A 3kW battery back-up: “This will be mounted and connected to the DB. It will run the light circuits in the home as well as the plug for the TV and wi-fi. This is a 3kW inverter with a 3.5kWh lithium battery, and installation is included with a certificate of compliance. The inverter has a 3-year warranty, and the battery has a 10-year warranty. This costs about R49 000.”
3. A 5kW battery back-up: It will also be connected to the DB and will run the light circuits as well as the plugs for the TV, wi-fi, and bedrooms, and it has a dedicated plug for the fridge. “If the air conditioners are plugged into the plug socket, we recommend getting this rewired to not run through the inverter. This is a 5kW inverter with a 5-year warranty and a 5.5kWh lithium battery with a 10-year warranty, also with full installation and a certificate of compliance. This costs R82 000.”
4. An 8kW battery back-up: This can run the home’s lights, plug circuits and two air conditioners, depending on their sizes. “This is an 8kW inverter with a 5-year warranty and 2 x 5.5kWh lithium batteries with a 10-year warranty and full installation and certificate of compliance. This costs R130 000.”
When it came to solar power, Müller explained how it worked.
He said electricity converted from sunlight was in direct current (DC), which was sent to the inverter/charge controller to charge batteries.
“It can even run the power in the home during sunlight hours.
“The inverter will convert this DC power into alternating current which is the type of power that we use in our homes for our appliances and lights. This type of solar does not just help with load shedding but also reduces your costs of electricity on a day-to-day basis.”
He said when looking to purchase such a system, there was no one-sizefits-all solution.
“Each person uses power differently and has different day-to-day habits. If a person in a one-bedroomed home wants to run only their lights, TV, wi-fi, bedroom plugs and fridge versus a three-bedroomed home, then yes, there will be a difference in the size of the system. A one-bedroomed solution would be a 3kW system versus a three-bedroomed home requiring a 5kW system.”
Müller said the price difference between running essentials and the entire home was substantial.
“If you are happy to have the basics running, for a three-bedroomed home, you would need to look at a 5kW hybrid system, which would be in the region of R135000. This includes 9 x 450W solar panels, 1x5kW hybrid inverter and a 5kWh lithium battery, with installation and a certificate of compliance.
“If this same home wants to run the entire property, this system size would then need to double, essentially. The biggest power-consuming appliances in a home are stoves/ovens, geysers, air conditioners, pool pumps and electric heaters. These are the appliances that would not run on a 5kW hybrid system as it would cause the inverter to overload. Installing a gas stove will help make your load shedding experience much easier.”
He said the costs did not vary according to the area one resided. It only depended on the distance it was situated from the purchasing company.
When it came to the durability of the system, he said it depended on the brand.
A good quality system, he said, could last between 25 to 30 years. This technology requires very little maintenance but has a yearly service where the contractor comes through and inspects the system.
An imperative aspect of solar is to ensure your solar panels are clean.