A SIMPLE WAY TO DETERMINE POWER NEEDS
HOW MUCH ELECTRICITY DO YOU REALLY NEED?
​
STEP 1: What would you like to keep 'on' when there is load shedding - make a list.
​
STEP 2: Find out how many Watts it uses per hour. You will find it on the label which is usually on the back or underneath the device. Now capture this number next to the listed item. Should you not find 'Watts' on the label, you should find the 'Output' - this consists of a Volt (V) value and an Amp (A) value. To convert this to Watts, just multiply the V value by the A value - Volt (V) x Amps (A) = Watts (W).
​
STEP 3: Add up all the Watts, but remember you don't use a kettle for an hour - only for 3 minutes until the water is boiled. So, be careful not to over-calculate.
​
​STEP 4: Once you have added up all the Watts you need to replace during load shedding, multiply this by the number of hours you'll need backup power for. Example: if you want to keep them powered for 2 hours, multiply the Total Watts per hour, by the number of hours, and this will give you the total number of Watts needed.
USE THE WATTS NUMBER TO CALCULATE THE SIZE OF INVERTER YOU WILL NEED
WHAT SIZE INVERTER SYSTEM WILL YOU NEED?
Once you have added up all the Watts you need from the 'simple' instructions above, click on this plug-in calculator to find out what your power need is in Amps. Don't worry about why at this stage, it will make sense later.
Now take the number of Amps calculated above and plug it into this calculator to see you kVA inverter size.
EXAMPLE OF HOUSEHOLD POWER USAGE
