Warranty vs performance guarantee – BIG DIFFERENCE.
You need to know this if you are planning a solar lighting project.
Warranties on the respective components are just that, and the terms and duration may differ on each of the components.
A performance guarantee is a guarantee of the predetermined lighting levels (whether it be to Australian Standards or not), the hours that the light is to be on (at 100% of that level), and with how many hours (or nights) battery back-up the system will provide.
You really should make sure you get both strong warranties and a performance guarantee.
The relevance to this is that many solar lighting systems start to dim as soon as the battery starts to lose voltage, therefore in a fairly short period of time is giving less than the pre-agreed light levels for the pre-agreed hours. This is not usually noticeable to the human eye until it is quite extremely dimmed.
This how some solar lighting suppliers miraculously offer high lighting levels from a disproportionately small solar panel and/or battery. Remember it is a straight power in/power out equation, nobody has the silver bullet when it comes to batteries or solar panels.
If one supplier is offering a brighter light with the same size solar panel/battery, or the same wattage light for the same hours with a smaller solar panel/battery, you are not receiving more for less, you will end up with an unreliable solar light and a premature battery replacement (batteries are one of the most expensive parts of a solar lighting system, and the added cost for labour and travel time to site to replace makes this a very expensive exercise).
Pleases note, a performance guarantee does not mean the supplier will guarantee a solar light will not go out for the duration of the guarantee. If prolonged bad weather exceeds the battery back-up (autonomy), or the solar light is installed in a location with shade (or more shade than pre agreed with the supplier) the performance guarantee will not necessarily stand.