Illuminating the Dark Side of Solar Lights

What’s not to love about solar garden lights? These radiant beacons of sustainability light the path to reduced carbon footprints and lower electricity bills. Ah, the joy of harnessing the power of photons! 

But before you fill your yard with glowing plastic orbs, let’s shed some light on the darker side of these luminescent wonders. Like those cheap solar lights that barely emit enough glow to guide a confused moth. Or finding nothing but darkness after a cloudy week. Or when they stop working completely after just a few months. Talk about a solar eclipse of hopes and dreams!

So, are they truly eco-friendly? As any artist can tell you, green is not a singular color. I’ve broken it down into all the color components—the hue, saturation and brightness of solar lighting—so you can decide if solar lights are truly a green investment for your yard. 

Construction/ Materials:  Sure, solar lights save on energy consumption, but their manufacturing and disposal carbon footprints can be high. Many are plastic and, even worse, black plastic. Many communities (including mine) do not accept black plastic for recycling. That’s because MRFs (Materials Recovery Facilities) often use optical scanners to sort plastic based on light reflection, and since black doesn’t reflect light, the scanners can’t pick it up. If possible, opt for lights made from recyclable materials. If your light comes with LED bulbs, be sure to recycle those properly since they contain tiny microchips that contain heavy metals such as lead and arsenic. The solar panels themselves can’t be recycled—at least not yet anyway! 

Batteries: Solar lights come with rechargeable batteries. Most of the batteries are nickel cadmium (Ni-Cd), nickel metal hydride (NiMH), or lithium (Li-Ion) and many of the smaller, cheaper lights use a AA size battery. NiMH batteries are preferred since they’re longer-lasting than Nicked Cadmiums, and contain fewer environmental pollutants. When your solar light stops working, the battery is often the problem. You can replace the battery with another rechargeable battery of the same size voltage. (The AA batteries are often 1.2v.) It may be possible to increase the mAh (a measure of the amount of energy charge a battery can hold which affects how long the lights will run) when you replace the battery, but you’d have to do some research on that to make sure it’s safe for your lights. Another measure to consider is Lumens, a measure of the brightness of the solar lights. The higher the lumens, the brighter your lights. 

Finally, be sure to recycle your rechargeable batteries properly! They do not belong in the trash. You can recycle your rechargeable batteries (and also your disposable batteries) at your local Staples store (which recycles all kinds of electronics) or visit Call2Recycle to find local and mail-in options for recycling your batteries. When storing your rechargeable batteries for recycling, be sure to follow safety guidelines. The EPA’s website includes the following handling precautions when storing or transporting rechargeable batteries: “Place each battery in a separate plastic bag or place non-conductive tape (e.g., electrical tape) over the battery’s terminals. Handle any damaged battery with care and appropriate personal protective equipment.”

Longevity: Solar lights can last up to 10-15 years if maintained properly! In addition to replacing worn-out batteries, you can clean the solar panel surface regularly to avoid build-up that would impede the panel’s ability to absorb sunlight. Lights with LED lights will use less energy and last significantly longer than other types of lights. 

Now that all your burning questions about solar lighting are (hopefully!) answered, go forth and choose wisely!