Choosing the right electricity backup
- October 25, 2022
- 7:35 am
As load-shedding continues, citizens are depending on generators. However, how does one choose the correct system?
Use the energy pyramid for efficiency:
- Energy saving (no or low cost): Switching off lights, setting geyser thermostats to a lower temperature, using less hot water, unplugging devices and appliances not in use, etc.
- Energy efficiency (low cost): Energy-efficient globes and other devices, geyser timers, heat pumps or solar panels for geysers.
- Renewable energy (higher cost): Alternative energy sources like solar water heating and solar panels provide excellent value, along with independence from the network and a lower impact on the environment.
Focus on efficiency and address the biggest electricity consumers in your home. Look at backup systems and batteries. Consider energy generation through alternative sources like solar panels.
When choosing a system, the best solution is determined by your current consumption and how energy efficient you are, not the size of your house or the number of people in it and secondly, by your requirements during an outage.
Requirements during a power outage:
- Lights: Small system of around R15 000, for sporadic outages of a few hours. It charges from the grid and switches to battery power when supply is interrupted. Energy-efficient globes help get the maximum runtime from batteries. Solar panels don’t make a notable savings difference.
- Lights and essential devices: Need to keep devices like TVs, computers, Wi-Fi, electric fences, alarms and fridges running, a 3kW inverter with 2.4kWh battery capacity (3 hours standby) is the minimum requirement. A 5kW inverter is recommended for upgradability. For around R60 000, a system with 1.8kW solar panels can be installed, with savings of about 8kWh to 10kWh on a sunny day.
- Lights, essential and non-essential devices: Adding devices like washing machines, pool pumps and microwave ovens, a 5kW inverter with a 4.8kWh battery (3 hours standby) is the minimum requirement. A 8kW inverter is recommended for upgradability. For about R90 000 one can install a 5kW system with 3kW solar panels and a 4.8kWh lithium battery, with savings of 15kWh to 18kWh on a sunny day.
- Heating systems: Includes geysers, stoves and heaters. The latter two can be powered by a solar panel or gas system, but for geysers a solar water heater system, i.e. using pipes, not solar panels, is strongly recommended smart investment.
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