Nowadays, because oil prices are getting higher and resource getting scarce, the hunt for efficient renewable energy has become of utmost importance. There are several natural sources that have been marked as clean, renewable energy – geothermal heat, wind, water current, and sunlight. Of all these, the one that has been getting a lot of attention is energy from sunlight, or solar energy. Solar panels are becoming more common, both on business establishments as well as residential areas. Advances in solar energy have also produced smaller, but more efficient solar panels, making them more practical to use on homes than they were before.
But solar panels, especially brand new ones, can prove to be too expensive. That’s where buying used solar panels come in. With the right information and by following some steps, used solar panels can give great power-to-dollar ratio.
Roof space, condition and orientation
Before you even think of buying used solar panels, consider the space available in your property. Solar panels are usually installed on the roof. Measure the area on which the panels will be installed so you have an idea of how many panels you can put on it. Keep in mind that older solar panels occupy a larger area than newer ones while still producing the same amount of energy.
Make sure that the roof is sturdy enough for the solar panels to be mounted on. If you need to repair the roof, work on that one first, since removing and reattaching the solar panels when they have been installed will take both time and money.
There have been debates on the direction the solar panels should be facing to get the most exposure from the sun. Studies have proven that to get maximum total energy production over the course of a year, install the panels on the roof facing south if you are on the Northern hemisphere and a north facing roof if you reside on the southern hemisphere. But there are newer studies showing that solar panels facing west reduce peak loads in areas where air-conditioning is a factor. Consider these two options when deciding on where to install the used solar panels.
There may be scenarios wherein installing the solar panels on the roof might not be feasible because of the factors above. This will require ground mounting which is more expensive because you need to a construct heavy-duty mounting system and allocate a huge amount of space on your yard before installing the used solar panels.
What to look for in used solar panels?
The easiest and probably the most important thing to check is the visual appearance of the used solar panels. Look for cracks, dents, scratches and effects of corrosion like discoloration.
Avoid used solar panels with obvious physical damage like cracked glass, broken connections, burn marks, and appearance of condensation. If buying online, ask for more pictures from the sellers. Make sure all the angles are covered so the damage, if there are some, can be properly assessed. Some of these issues can be fixed but it may not be worth the trouble and can result in a higher total cost. Some contractors might not even sign off or work on the installation if they see damage on the panels or the circuitry, because these are considered fire risks.
Brownish colorations, circuitry, bypass diodes, connections
Brownish colorations on the panels might seem like the panels are unusable, but that’s not generally so. Older solar panels were made of plastic substrates that turn brown under prolonged exposure to the sun. The internal circuitry should be checked especially burned-out bypass diodes, as well as the connections between the solar cells in a panel. But remember these can easily be fixed by replacing the broken components and some soldering. Some sellers even sell used solar panels in this condition as scrap, which means great bargain for buyers.
Find out how old the panels are
Determine the age of the used solar panels. Efficiency of solar panels decrease over time so used ones will not give the same power output that they used to when they were brand new. Brand new solar panels usually put out 10 percent higher output than the indicated rate. Some warranties indicate a 5 percent drop in the efficiency of solar panels after 5 years of normal usage, but only if they are actually used. Solar panels that remain in storage keep their efficiency intact throughout the years. Solar panels have an expected lifetime of 25 years at the very least. But most exceed that number if well taken care of. There are panels that will only drop 15% in efficiency after more than 30 years under the sun.
Check how much electricity you will get out
Check the voltage output using a voltmeter or multimeter. Set the meter to DC volt and measure by placing the leads on the positive and negative terminal of the used solar panel. Under a full sun, a 12 volt panel should give an output of up to 21 volts. Set the meter to DC amperes in a high enough range and measure the current, also in full sun. For a 12 volt panel, the usual rated current is 17 amps. Multiply the rated voltage by the current to get watts of the used solar panels.
Where to buy used solar panels
eBay can be a great source for those who are looking for used solar panels. But it can also be a hit and miss affair because there might be no way to physically check the merchandise. Check the reputation of the seller by looking at the number of positive or negative feedbacks. The feedback comments are from buyers who are satisfied, or otherwise, of the product they got from the seller and therefore a good indicator of whether the seller can be trusted or not. There are lots of sellers of used solar panels in eBay.
Look for commercial buildings and factories that are changing or upgrading their solar panel installations. Since these used solar panels were meant for industrial use, it would mean higher efficiency and more value for your money.
Some insurance companies may sell damaged or broken solar panels which they salvaged from homes owned by claimants of home insurances. They might sell these used solar panels at unbelievable cheap prices. These used solar panels might require some minor fixes before they can be utilized, but if you are looking to get a solar bargain they are the perfect choice.