5 things to watch for when buying used solar panels

Though solar panel systems can offer a dependable, cheap and environmentally-friendly source of energy for your home, they're expensive. Some systems can cost several thousands of dollars depending upon the materials from which they're built and their ability to absorb and transform sunlight into power. In fact, the upfront investment of new solar panel systems can often require decades in energy cost savings to recoup. Because of this, buying and installing used solar panels can seem attractive. While you can find a great bargain, there are also several potential pitfalls to buying them used. Below, you'll find a list of 5 things to watch for when shopping for used solar panels.

Things to watch for

#1 - Energy output

As solar panels age, they lose some of their ability to output power. This is especially true if the panel uses amorphous silicon. That, in itself, should not discourage you from buying used solar panels. Just be aware that you'll likely need a greater number of panels to produce the same power of new units. That means you'll need more room to set up the panels in order to absorb sufficient sunlight.

#2 - Loose connections

If you're not looking for them, loose connections between the solar cells in the panels can remain hidden. If the connections are loose, it's going to affect the performance of the solar cells. It may even prevent the panels from absorbing sunlight properly. If you're willing to fix the connections, the panels may still be a bargain. But, understand that fixing them requires an electronics solder and can be more trouble than it's worth.

#3 - Damaged panels

Older solar panels can often take plenty of abuse. As a result, you may notice cracks in the glass, moisture underneath the cover, or connections that are completely broken. Similar to loose connections, if you're willing to fix the problems, the used panels may still be a great deal.

#4 - Dollars per watt

Because older solar panels generally output less power than newer panels, you need a way to compare value between them. The best way is to test the power output with a voltmeter. To do so, you would measure the output across the "+" and "-" terminals of each panel. If the used solar panel is a 12-volt unit, the voltmeter should show close to 21 volts. That reflects the simulated output of the panel while it's completely exposed to the sun. By converting the number to watts, you can approximate the dollar value per watt the used solar panels will yield.

#5 - Unsteady current

Often, used solar panels are damaged under the surface. The problems aren't easy to identify. For example, the panels may have sustained moisture in the internal circuitry. If this happens, you may see fluctuations in the voltage output while testing. This occurs most often with amorphous silicon panels. Needless to say, bad circuitry implies a solar panel that doesn't work.

Where to buy used solar panels

Now that you have some guidelines of what to look for when shopping for used solar panels, it's time to hunt for bargains. Two of the best places to look are eBay and CraigsList. As people upgrade their current solar energy systems, they'll offer their used panels for a fraction of the price of buying them new. But, be diligent. Inspect the panels and test them. With a keen eye, you're bound to find a great deal.