Buying used solar panels is a great way to reduce the high cost of going solar at home. However, like anything else you buy used, you must shop carefully to make your dollars go as far as possible. So what is the best way to judge used solar panels? These tips should help you to separate the gems from the junk.
1) History matters – Two panels of equal type, size and age will often perform differently based on their usage history. Panels that have seen more action will not perform as well as an identical panel that has been in storage for most of its life. Find out as much as you can about how the used panel was used in the past.
2) The individual cells are what “collect” the energy from the sunlight. panels with higher numbers of cells can collect more energy and that corresponds to a higher wattage rating for that panel, BUT…
3) Also look for the panel’s original efficiency rating. This describes the amount of energy per square inch that the cells will produce. This matters because a smaller panel with a higher efficiency rating can often output the same wattage as a larger panel with a lower efficiency rating.
4) Match the panels to the job they’ll be doing. If you are going to power a limited number of circuits, or even a single appliance, you have to know how much energy it uses and make sure the assigned panel(s) will handle it.
5) Even new solar panels are only warranted to produce some number less than the stated wattage (for instance, a 200 watt panel may only be warranted to 180 watts). This means it is better to use a panel that has a higher capacity than the application requires.
6) Your system will use an inverter to change the energy from direct current (DC) to alternating current (AC). Like the panels, inverters have an efficiency rating to consider. An inverter with a lower efficiency rating will lose more of the energy produced by the panels than one with a higher rating. The capacity of a high efficiency panel can be restricted by a low efficiency inverter.
7) Test used panels for wattage and voltage before purchasing whenever possible. It’s also helpful to test the individual cells within a panel in certain circumstances. Sometimes an under-performing panel can be improved by re-wiring around a bad cell or two. If the price is right, this might be a smart move.
8) Look for free panels that can be used for parts. If the cells are good, these can often be re-assembled into a new panel.
9) If you intend to convert your home to solar power yourself, get a good quality instruction guide. It will definitely save thousands of dollars over the cost of having it done professionally., and guide you step-by-step through the assembly and installation process, plus provide excellent information on where and how to find the components you need – including used panels.
You can find out more about used solar panels here.