Before you buy a solar system
Most disappointment with solar comes from not knowing what you were buying. This page is the short version of what to know first.
The inverter does not make power, and it does not store it
In everyday talk, "I bought an inverter" usually means the whole system: the panels, the batteries and the inverter together. On this page, "the inverter" means the box itself, and that box neither makes power nor stores it.
The panels make the power. The batteries store it. The inverter only converts it from the direct current the batteries hold into the alternating current your appliances use.
This is the correction that matters most. If you think the inverter is where the power comes from, you will buy the wrong parts and be disappointed by the night.
So a bigger inverter does not give you more hours. More hours come from more batteries, and more charging comes from more panels.
How to work out what you need
List everything you want to run. For each one, find its power in watts (it is usually on a label on the back or underneath) and how many hours a day it runs.
Multiply the watts by the hours to get the energy it uses in a day, in watt-hours. Add them up. That total is what your batteries and panels have to supply.
Separately, note which of them run at the same moment, and add up those watts. That is what the inverter must be able to carry at once.
Appliances that start with a motor, such as a freezer or a pump, ask for more power for a moment when they switch on. Tell whoever is quoting you which ones you have.
Our checkout asks the same thing, "What do you want to power?", so that whoever helps you starts from your list.
Why a system fails to meet expectations
It was too small for what is plugged in. The battery bank was too small for the night, so it runs flat before morning. Things you forgot are on all the time, such as a router, a fridge or a charger. The cable is too thin for the current and gets hot. There is no earthing and no surge protection. The batteries do not suit the inverter.
Every one of these can be checked before you pay, if the quote says what is in it.
What a proper quote lists
Ask for it broken down: the panels, the inverter, the batteries, the protection (breakers, surge protection and earthing), the cable, and the labour. Each with a brand and a size.
A single figure with nothing under it tells you nothing, and you cannot compare it with another seller's. Ask every seller for the same breakdown, us included.
What to check before you pay anybody
A real address you can visit. A registered company you can look up: a company's registration number can be searched on the Corporate Affairs Commission's public register. A written list of what you are getting.
When you pay by bank transfer, check that the name your bank shows for the account is the company's name before you confirm.