MTN’s general manager for engineering Zoltan Miklos has reduced his electricity bill to below R1,100 per month using a cost-effective solar backup system and power-saving techniques.
Apart from being an experienced telecommunications executive, Miklos is also an expert in electrical systems and energy efficiency.
MyBroadband spoke to Miklos about his setup at home, and he gave tips on how to implementing a similar system at your home.
Eskom recently implemented an average tariff increase of 17.8% on electricity supplied to municipalities, while its direct customers have paid 15.06% more since 1 July 2021.
Municipal customers in Cape Town, Johannesburg, and Durban pay between 13.48% and 14.59% more than last year.
With Eskom expected to hike prices further in the coming years, and with the constant threat of load-shedding looming, many homeowners have resorted to self-generating power and battery backups.
Large solar PV and battery installations can be expensive, with costs taking a long time to recoup. At the same time, smaller solutions can be ineffective.
Miklos uses a solar backup system consisting of eight solar panels, a 5kW Victron inverter, and three 3.6kWh Pylontech lithium-ion batteries.
Miklos said the key to bringing down your bill was understanding your consumption habits and requirements.
“Understanding your load requirements in terms of demand and time thereof is a start,” Miklos said.
To do this, he installed an energy meter on the incoming feed to his house to measure energy consumption.
This allowed him to set the best times on his system for the house to draw power from either solar, his batteries, or the grid.
“For example, I schedule certain loads to take advantage of solar output during the day, such as the pool pump,” he stated.
With the data provided by the meter, you can also see which appliances use the most electricity.
Miklos said appliances with a motor or heating element are the prime suspects.
“Electrical geysers, ovens, heaters, pool pumps are major culprits; to a lesser extent, hair-dryers because they are not on for long enough,” Miklos said.
To reduce the impact of some of these appliances on his usage, Miklos shifted several appliances to gas.
This includes a gas hob, a gas geyser for the bathrooms, and an under-counter geyser in the kitchen.
“The under-counter geyser was one of the best investments in my view because the hot water is instantly delivered, and you are not pulling hot water from the geyser,” Miklos said.
“This is especially a factor in winter where you waste power waiting for hot water to arrive where you need it.”
Miklos’s gas geyser was installed inline to the electric geyser.
“I get the electric geyser to the required temperature in the day using a timer and solar yield,” Miklos stated.
“The gas geyser detects the incoming temperature and compensates accordingly.”
“If there is load-shedding, my gas geyser is on the critical loads-circuit on my backup system as it requires a small amount of power to operate.”
“On cloudy days, I turn off my electric geyser via the timer and only rely on the gas geyser,” Miklos added.
With the interventions above, Miklos’ battery backup can support his critical load requirements of less than 500W, including an energy-efficient fridge, lights, TV, decoder, fibre ONT and Wi-Fi router.
His backup system also has a sensor on the incoming feed to the house, which provides more accurate data on voltage and current.
Importantly, demanding appliances such as air conditioners and the washing machine are not connected to the backup system.
To compensate for times when these may need to be used during load-shedding, Miklos also has a stand-alone generator on standby.
This type of setup has allowed him to keep his home’s grid electricity usage below 600kWh, despite having a household of four people.
At this usage, he remains on the Block 1 Eskom tariffs for a single-phase 60A household, which is currently priced at 182.21 cents per kWh. Going above this threshold would cost much more — 309.71 cents per kWh.
This means Miklos would pay a maximum of around R1,093.26 for his household’s electricity usage.