Article By: Logan Hannen

What is up, watchfam?! Today, we’re going to dive into the two distinct kinds of light-powered movements: solar powered and Eco-Drive.

So let’s get a pretty important difference out of the way – “solar powered” simply refers to any watch movement that uses the power of the sun to power the watch, and has been used over the last couple of decades by a great many brands, typically Japanese but with the odd Swiss in there as well. Then we have “Eco-Drive” which is a technology pioneered and used exclusively by Citizen. That, however, is far from the only difference.

How Seiko Solar Watches Work
Source: ABlogtoWatch

When we discuss a solar powered movement, there are really three basic parts to its construction and design that make it especially functional. The first is the dial which, on many a modern solar watch, is transparent to some degree. This allows for the rays of sunlight to penetrate directly into the layer below the dial, which is essentially a miniature solar panel. This collects the light energy, converts it to electricity, and then transfers that electricity to the movement. All in all, pretty straightforward.

How Citizen Eco-Drive Works
Source: Citizen

Now let’s take a look at Eco-Drive. Right off the bat, this movement gets some serious credit, being the first wristwatch powered by only light using a solar cell under the dial. Prior to this, solar powered watches had to fix the solar cell as a part of the dial design, which often resulted in some truly atrocious looking pieces (see: most solar watches from the 70s and 80s). What Citizen had accomplished was incorporating the solar cell into the design of the watch by making it unseen behind a semi-transparent dial. Sure, most modern solar powered watches do the same thing, but Citizen Eco-Drive was the first, and also the first to accept natural and artificial light as sources of power.

Eco-Drive watches also have the capacity to run anywhere from 5 months to 7 years, depending on the model. But more importantly, because the pieces use a primary and backup power cell, they can last, in theory, for well in excess of 20 years with the proper care and maintenance. The result is not having to constantly be disposing of batteries every 3-5 years, along with other environmentally friendly advancements that won the brand the Eco-Mark Gold Prize in 2014, the first watch brand in history to do so.

Alright, that’s all good and well, but is there really a benefit to one over the other? Empirically, I’d say probably not. The Eco-Drive technology is by far the more environmentally friendly option, and it also comes with the added panache of being the first proper solar powered watch to incorporate the technology into traditional watch design. Beyond that, though, when it comes down to it, any kind of solar powered movement is still one step ahead of the game, both in terms of practicality and environmental consciousness, and with how elegant some of them look these days, it becomes easy to see how a solar powered or Eco-Drive movement can make a great addition to your collection to help you keep it classy, watchfam.