FAQ – Backup Power Systems

There are 4 ways to determine the energy usage of an appliance.

• Look at the nameplate on the appliance
• Lookup the applicant model number on the manufacturer’s website.
• Lookup the energy usage in the manual that came with the appliance.
• Measure it with an energy meter or current meter.

This PDF file lists the most common appliances and will give you an indication of typical energy ratings. Click here to download the PDF file,  GES appliances, typical energy usage  

One can put the whole distribution board of a house on backup power. But this is not recommended as the amount of backup power and energy is limited.

Typically one would like to exclude high energy consumption appliances that are not essential from being supplied with backup power. Appliances such as stoves, ovens, geysers, pool pumps and underfloor heating.

So one would divide the distribution board up in two sections, or even add an extra DB board next to the existing DB board if there is not enough space.

The one section of the DB or the new external DB would be supplied just with grid power, and the other section with grid power and backup power.

An extra earth leakage protection(ELP) switch is installed in this new DB board. So each section/DB has it’s own dedicated ELP.

Then certain existing circuits can be moved over to the new “backup power DB Board”.

Alternatively, extra plugs can be installed in addition to the existing plugs, that are only for backup power, if one circuit supplies both essential and non-essential equipment.

 

Example of a dedicated external extra DB for backup power.

• Your current electrical installation must be up to standard and have a valid certificate of compliance before we will install our backup power solutions. We can arrange this for you.
• An assessment of exactly what equipment and circuits need to be on backup power. The total load of all the equipment on the backup power equipment and circuits needs to be calculated, in order to stay below the maximum power rating of your chosen inverter. We can assist in this.

• An inverter is required for each phase that requires backup power.
• One can combine three inverters, and then set up communication between them to create a three-phase supply.
• But as inverters can be costly, we recommend the following: Only install one inverter to supply one of the three phases with have backup power. So the other two phases will have no backup power.
• Then move all the essential loads that must be backed up, to this one phase. The high consumption equipment such as geysers and ovens can be left on the other two phases.

There are basically three ways to calculate the power and energy requirements of a solar power / backup battery system.

1. From your monthly electricity bill. The total amount of energy used per month will give you an indication of how much energy needs to be generated by a solar system
2. Install an energy logging device, this device will tell you the peak amount of power drawn at once, and the total energy consumed per day and per month. These devices are widely available to buy online, one good example is the Efergy Energy Logger.  https://www.sageonlinetools.co.za/Render/EcomProduct/blxcmk?cat=57427
3. Download and complete our “Energy Usage Calculator” This can be completed and emailed back to us. Click here to download our “Energy Usage Calculator.