Has Japanese solar watches come this far? Citizen's new 2025 model, Eco-Drive One

Every year, we hold an end-of-year project in which prominent watch journalists highlight their "one watch they're interested in" or "one watch they recommend" from among the new models released in 2025. While not particularly well-known, Chieko Tsuruoka of the watch magazine Chronos Japan and webChronos editorial department felt she had to do it, so she introduces the Citizen Eco-Drive One Ref. AQ5010-01A as one of her favorite watches of the year.

The wave of evolution and sophistication of watch dials is also affecting solar watches.

　The watch industry also has its trends, and 2025, like last year, saw smaller case diameters and a more diverse range of dials. This article focuses on dials. While colors were previously limited in variety, neutral colors and gradients have been added, and the decorations available have become more diverse. As a result, this year's new releases are a riot of dials, overflowing with the ingenuity and ingenuity of each manufacturer.

　Solar watches are no exception to this evolution in watch dials. Most solar watches have a solar cell placed under the dial, which receives light and converts it into electrical energy to power the watch. The secondary battery installed alongside them can repeatedly charge and discharge this electrical energy, so unlike quartz watches that are powered by primary batteries such as button batteries, they do not require frequent battery changes. However, to ensure the energy needed to run the watch, the solar cell must be exposed to plenty of light to charge. For this reason, many solar watch dials have used transparent plastic materials such as polycarbonate. While solar watches are convenient, these dials can inevitably end up looking cheap, which is why they are said to be difficult to convey a sense of luxury.

　However, in recent years, models featuring a wide variety of dial expressions, primarily from Japanese brands specializing in solar watches, have been popping up in the watch market thanks to their innovative ideas and technological refinement. Among these, I personally believe Citizen stands out from the rest. And as you can see from the models already released, this year was also full of outstanding pieces. The quality and design of all of them, including the dials, are guaranteed. It was difficult to choose, but I chose the Eco-Drive One Ref. AQ5010-01A, which surprised me the most.

At the new product launch, the professor says, "There's something dangerous over there!"

　I first saw the AQ5010-01A at Citizen's new fall/winter collection launch event in September. The entire Chronos editorial team headed to the event, and in the spacious venue, we all took our time touching and feeling the actual watch at the booths of the new models that caught our eye, taking photos. I think I was looking at The Citizen (The Citizen's new releases were also great, of course). Suddenly, Hakase, or Editor-in-Chief Masamasa Hirota, came over to me with a certain Ms. M from Citizen, and said, "There's something awesome over there!" If these two watch nerds thought it was awesome, there was no reason not to go and check it out, so I headed over right away, and that's when I came across the AQ5010-01A.

　At first glance, I couldn't help but say, "Wow! Isn't it too white!?" The dial wasn't silver, but a matte white (off-white).

　As mentioned above, solar watches need to have a transparent dial. Therefore, if they are painted or made of opaque materials to give them a luxurious or unique look, they will not receive enough energy to power the watch. However, this model is completely white, with no sense of transparency at all.

　However, the dials of Citizen's solar watches in recent years, especially the Eco-Drive One and Attesa, are completely opaque and almost look like they're made of brass. In fact, I had a hard time deciding between the Attesa "Platinum Shine Collection" and the "DEAR Collection" for this article.

　However, considering that the silver and white dials of solar watches tend to disperse light and are more likely to be transparent, making them less likely to give off a sense of luxury than black or blue, the extraordinary qualities of the Eco-Drive One AQ5010-01A are more clearly conveyed.

　The dial is actually painted white. While one might think that light is drawn in through the small seconds, it is in fact a solar cell placed under a black ring around the outer edge of the dial that captures the light. Other companies have also taken the approach of overcoming the constraints of dial expression by using highly efficient small solar cells, but the Eco-Drive One in this watch is equipped with a movement measuring just 1mm. Seeing this watch, which has a matte white finish while maintaining a power reserve of approximately seven months on a full charge in this extremely limited environment, he was amazed, saying, "Japanese solar watch technology has evolved and deepened to this extent."

　With a black and white color scheme, three hands, and a case that is 36.6mm in diameter and 4.5mm thick, it is full of classic elements, making it a high-end dress watch for adults.

　The only downside is that it's a limited edition model that will only be sold at select stores, with only 160 units produced. This watch was just released in December, so be sure to check it out in store before it sells out. You'll surely be able to experience the latest in Citizen's solar watch technology and look forward to what's to come next year.