In order to determine the inverter and battery size required you will need to get that calculator out.
For the Inverter Calculation:
- Decide what appliances you want to power during an outage – normally TV, Beer Fridge, Router, Small LED Bedside Lamp, Laptop
- Make a note of the Wattage as displayed on the back of each device
- Add all the Wattage numbers up together
- The wattage numbers will give you the inverter size – normally 600W is sufficient
Battery Size Calculation:
- Multiply the total Wattage by the number of hours you expect to run the inverter for
- Divide the total Wattage by battery voltage – normally 12 volts – that will give you the Amp Hour Battery Size required
- Lead Acid batteries fail if you drain them by more than 80%
- So, just to be safe, take the figure from 2 above and times it by TWO – this will allow for battery drainage down to 50%
- This will also allow for a quicker recharge to be ready for loadshedding again if we go past Stage 3.
What type of inverter is best?
If you will NOT be running any electronics off of the inverter then a Modified Sine Wave Inverter will be fine.
If you WILL be running any electronics off of the inverter then a Pure Sine Wave Inverter is highly recommended.
In Pure Sine-wave inverters the output wave-form is a sine-wave with very low harmonic distortion which outputs clean power like Eskom supplied electricity. This allows inductive loads like microwaves and motors to run faster, quieter and cooler, educes audible and electrical noise in fans, fluorescent lights, audio amplifiers, TV, fax and answering machines and prevents crashes in computers, weird print outs and glitches in monitors.
A Modified Sine Wave Inverter will cost less than a Pure Sine Wave Inverter.
Straton Solar has 3 Portable Inverter Kits (Eskom in a Box) available from their premises in Mangold Street, Newton Park:
- KIT 1: 1 x 12V Pure Sine Wave Inverter 600W plus 1 x 100Ah 12V Deep Cycle Battery (Ideal solution to back up power for TV + DSTV with an LED light): R6250.00 Inclusive
- KIT 2: 1 x 24V Pure Sine Wave Inverter 1000W plus 2 x 100Ah 12V Deep Cycle Batteries (Ideal solution to back up power for TV + DSTV with an LED light for higher output power and longer backup times): R10250.00 Inclusive
- KIT 3: 1 x 24V Pure Sine Wave Inverter 1000W plus 2 x 200Ah 12V Deep Cycle Batteries (Ideal solution to back up power for TV + DSTV with an LED light for higher output power and longer backup times): R16500.00 Inclusive
Pre-ordered Kits can be picked up from Straton Solar Offices at 13 Mangold Street, Newton Park. Delivery and plug in anywhere within Nelson Mandela Bay will cost R500.00. These are portable solutions only. Availability subject to supplier stock. Prices are subject to change without notice and includes VAT. E&OE COD only,
But I Want to Run My Whole House With No Interruption When Loadshedding Kicks In?
In order to do this you have two off the shelf choices:
- Auto Start Generator
- Fixed Inverter and batteries
Both have pros and cons and once the cost of installation and setup are factored in both solutions are much the same price – Straton Solar has installed 4 KW Solar Panel Ready Hybrid inverters and 800AH of batteries for R65 000.00. Auto Start Generators excluding installation and setup start at around R40 000.00
The Inverter advantage is that it has a 5 year standard warranty (as opposed to 1 year on a generator), runs silently, you do not need to top up with petrol and it is green.
The number of inverter choices can be quite confusing and, in a word to the wise, non-experts would be well advised to purchase from a local supplier/installer who can give advice and support in the case of a warranty claim. Inverters and batteries are heavy items to send back to another city should they need to be repaired. Factor into that the frustration of a long wait and daily loadshedding one is tempted to ask if the price is worth the effort.