by Dr Andrew Dickson, CBI-electric: low voltage
Between March 2022 and June 2023, there has been a 349% increase in solar rooftop PV installations. With households and businesses now producing over 4400 MW, electricity generated from the private sector is predicted to exceed the output from Eskom’s generation fleet by 2025. But if those who have invested in these systems aren’t careful about how they use them, they could end up back in the dark.
When people switch from using electricity derived from the grid to electricity generated by these systems, they often assume that they will be able to power their homes in the same way, especially during outages. Unfortunately, however, they run the risk of draining the battery, which can only store so much electricity, or tripping the inverter. This is where smart home technology can prove useful.
Four ways this technology could be used to help protect backup power systems:
1. Determining essential and non-essential loads: To avoid being left in the dark when the power goes out, it's crucial to manage the backup system properly to prevent draining the battery or overdriving the inverter with multiple loads operating at once. This means understanding which loads are essential and which are not, as well as when they should be turned on during power outages. To do this, you need to know the electricity usage of different loads and your household's energy consumption patterns.
Smart home devices with monitoring capabilities can provide valuable insights to help you make data-driven decisions about which loads to connect when using backup power situations. For example, in my home, I've connected the security system, internet, entertainment system, kettle, and lights in my childrens' bedrooms. This ensures that the essential loads, like lights, stay on during power outages while making the best use of the backup power system's capacity. By being conscious of electricity consumption, you can optimise your backup power setup and cost.
2. Automating loads: With real-time monitoring, users can see how much solar energy is being used and where it's being consumed. If connected loads are drawing excessive electricity, especially on days with frequent power outages, smart home technology can automatically turn off energy-intensive devices. This helps to balance the energy generated by the solar system with the load, ensuring power is available for all times during challenging periods.
3. Allocating energy: Essential loads shouldn’t all be used at the same time or else this might drain the battery faster than planned or, in an unwanted case, trip the inverter. Smart plugs can be set up in such a way that if one is switched on, the others won’t be able to turn on. This way, users can direct backup power to the most important appliances and systems in their homes first. For example, in my case, my wife and I prioritise powering the kettle since we have a baby, and we need boiling water ready for making formula whenever our little one needs to be fed.
4. Avoiding voltage fluctuations: Undervoltage often occurs once power is restored after load shedding. This is when the grid voltage dips for a short period. Most inverters are equipped with an adequate level of protection against this, but if power is being switched on and off more frequently or voltage dips occur a number of times while the supply is stabilising, it could result in failure of the inverters protection. With a smart controller, users can delay when power from the grid is returned to the system, ensuring that the systems operational lifespan is maintained.
With rooftop solar installations costing between R80 000 and R200 000, smart home technology can help South Africans who have undertaken this investment to optimise their spend, maintain power and energy availability and protect these systems to preserve their longevity and ensure their effectiveness. Ultimately, this will help keep your lights on as well as those of the country.
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