Load-shedding will remain a reality for South Africans for the foreseeable future. This has been confirmed by the CEO of Eskom, Andre De Ruyter, during his recent update on the state of the power utility’s generation system.
De Ruyter painted a bleak picture on the prospects of load-shedding over the next few years, as Eskom’s Energy Availability Factor (EAF) has seen a continued decline in the past few years due to its ageing coal power plants.
He highlighted that Eskom’s plant reliability maintenance programme means that load-shedding should be less frequent after September 2021, but stressed that the country would still suffer a power shortfall for the next five years.
Continued load-shedding and power outages mean many people are looking for backup power solutions for their homes and businesses.
Marketing Director of the One Energy Group, Teresa Settas said South Africans are also fed up with the rising electricity prices and mooted penalties for making alternative arrangements to get the power that Eskom cannot reliably or affordably supply.
Settas added that the parlous state of South Africa’s municipalities should also be of great concern, with outright collapsing of services and governance a daily occurrence.
“An alarming increase in cable theft and failing electrical infrastructure at municipal level are as harrowing as Eskom’s dire state of financial and technical affairs,” Settas said.
This, she claimed, compromised peoples’ productivity, safety, security, and quality of life.
Settas advised those looking for a backup power solution should take a long-term view to going off grid.
“Starting your journey this way is a crucial step towards greater grid-independence and lot more affordable than people realise,” Settas stated.
“With the advances in solar technology and pricing, you can hedge your electricity costs for the next 20-25 years and secure your supply at less than half the price that Eskom can supply it, by making savvy investment decisions today.”
She recommended that consumers start with a scalable, quality solar PV hybrid solution that takes care of their immediate needs for back-up power during load shedding and power failures.
“Initially your system is configured as a back-up UPS type solution to provide backup only during outages,” Settas said.
As your budget allows, you can expand this with solar panels to generate your own electricity, providing back-up power and saving you in electricity costs.
Setta said a good starting combination for backup power is a 4.6kW inverter paired with a 3.5kWh lithium-ion battery. This would cost around R71,000 with installation.
While initially configured as a UPS, it also comes with a charge controller that allow you to connect solar panels to operate as a hybrid solar system at a later stage.
Adding 4kW of solar panels will cost around R47,000 with installation that includes the required electrical protection.
After this, you could add another 3.5kWh battery for around R21,000 to increase your storage capacity.
This would mean you effectively have the ability to store 7kWh of energy, with a peak output capacity of 4.6kW at any given time.
How long a battery back-up system will be able to power a home is dependent on two factors:
- Size of the battery bank.
- Amount of load from connected appliances.
To protect the battery’s lifespan, it is automatically disconnected when its battery is drained by 80%.
Below is how long a single 3.5kWh lithium-ion battery would last under various loads, taking into account that 20% of the capacity needs to remain available:
- 2,000W – 1.4 hours
- 1,000W – 2.9 Hours
- 800W – 3.6 Hours
- 600W – 4.8 Hours
- 400W – 7.1 Hours
- 200W – 14.3 Hours
Many people may look for cheaper ways to move off the grid, but Settas cautioned consumers against cheap, quick fixes which promise the world with something as small as a R10,000 inverter.
“If it were that easy and capable of taking you off the grid, everyone would have done it long ago,” Settas said.
“There are many unqualified fly-by-nights who have popped up, with even more questionable tech offerings and sub-standard installation quality. Buyer beware.”
After adding a battery backup system, it is advised that households reduce their daily electricity load by taking their water heating off the grid. This can be done by installing a solar geyser.
According to Settas, an electric geyser typically accounted for between 30% and 40% of the monthly electricity usage in a home.
Substituting this for a solar version will mean you can use a smaller and more affordable PV solution.
A fully installed 200-litre solar geyser would cost around R27,000.
Splitting your essential and non-essential loads at the distribution board will allow this combination of equipment to take the average household using around 25kWh of power per day 80-90% off the grid.
“No more outrageous electricity bills and you won’t even know when there is load shedding or a power outage,” she said.
The table below shows a breakdown of the setup described by Settas, with installation costs included in all cases.
|4.6kW Goodwe inverter + 3.5kWh Pylontech battery||R71,000|
|4kW solar panels||R47,000|
|Additional 3.5kW Pylontech battery||R21,000|
|200-litre solar geyser||R27,000|