Seiko Solar Watches

Introduction to Seiko Solar Watches

Solar watches have been around since 1976, and Seiko released its first solar model in 1977. Since then, solar has evolved from a novelty to a useful feature that eliminates the unavoidable hassle of replacing a quartz watch battery. Today, the Seiko catalog includes countless solar watches including divers, chronographs, dress watches and more.  

The History of Solar Watches

Photovoltaic solar cells were developed in 1954. More than two decades later, Roger Riehl succeeded in miniaturizing the technology to power the futuristic Synchronar solar watch, which hit the market in 1976. In place of a typical watch face were solar cells hidden beneath two rectangular windows. The digital display was on the case’s side. While the Synchronar clearly had an engineering-driven design, the technology captured sufficient energy from light to power the watch indefinitely. 

Soon after, Seiko, along with Citizen, Casio and others, integrated the technology into more attractive analog and digital watches. Seiko’s first, the steel LCD alarm chronograph A156-5000 with the classic late-1970s chunky digital design, debuted in 1977. In addition to the standard version, Seiko also produced the Sports 100 and the plastic-bezel Silver Wave, which is the rarest of the three. The exposed solar panel on the face of the A156 and many future Seiko solar digital watches was a common design element that was both functional and attractive. Modern digital and analog watches, however, are often indistinguishable from those powered by traditional automatic or quartz movements.  

Solar Technology and Benefits

Solar watches are equipped with solar cells that convert light into energy. The energy is stored in a rechargeable battery, which is then used to power a watch’s quartz movement. Any light source will provide energy, but the intensity determines the amount of power converted and how quickly the battery recharges. The unit of measure for the light intensity cast on a surface is the lux. At roughly 100,000 lux, direct sunlight is the most intense light source; a typical office environment might be 500 lux. Harvesting a day’s worth of power for a modern men’s solar watch takes about a minute of sunlight compared with 60 minutes of exposure to interior light. Charging a women’s solar watch takes approximately twice as long. A depleted solar watch usually just needs to be exposed to a light source to resume normal operation.

The primary benefit of solar is years of maintenance-free operation. At a minimum, the rechargeable battery in a Seiko solar watch should last 10 years. With battery efficiency gains, newer models should last significantly longer before a battery change is necessary. Replacement batteries typically cost $20-$30. The clean energy source also has environmental benefits since fewer batteries end up in landfills.

Popular Seiko Solar Watches

Seiko currently produces a wide range of solar watches across several collections including Prospex, Astron, Coutura, Seiko Premier, the women’s Diamond collection, and dozens of Classic and Core Series three-hand and chronograph models. Steel is most common, but gold-plated steel and titanium models are also available. Gone are visible solar cells. Instead, the solar cell is placed beneath seemingly opaque dials in white, black, blue and even ornate textured and mother of pearl finishes that allow light to pass through. Modern solar watches will operate for more than six months on a full charge. Popular models include:

• The Astron GPS Solar collection, which includes both production and limited-edition models that automatically sync using GPS to provide +/- 1 second per 100,000 years accuracy across all world time zones. There are four generations of Astrons, including new releases like the Japanese domestic market (JDM) Women’s Solar GPS 3X series.
• Coutura Radio Sync Solar watches that receive radio signals and automatically adjust to the precise time. Chronograph, world time and dual time zone variants are available.
• Prospex Solar dive watches, which are true tool watches with water resistance to 200 meters. The 47.5mm analog/digital hybrid Arnie Tuna (Reference SNJ029) is driven by the Seiko in-house H851 movement. The Save the Ocean Special Edition (Reference SCC701) and classic dive-watch styled PADI Reference SNE549 are also great choices. Several Radio Sync models including the World Time chronograph Reference SSG017 with 100-meter water resistance are also available.  

Seiko Solar Watch Value and Collectibility

From a value perspective, Seiko Astron GPS Solar watches tend to sell at the highest prices. New limited editions including the Kintaro Hattori 160th Anniversary model (Reference SSH073) sell for nearly $4,000 while new and preowned titanium PVD Reference SSH023 and the 2020 Djokovic regularly sell for more than $2,000.

Standard production models frequently appear for well under half that amount. New Prospex solar divers list for around $500, and preowned versions can easily be found in the $150 to $300 range. Hundreds of Core Series Seiko solar watches are available at any given time for less than $150, and great bargains at prices below $20 are abundant.

Vintage digital Seiko solar watches remain highly collectible and appear frequently priced at less than $100, with a few pristine examples selling for roughly twice as much. For Seiko collectors who also collect Star Wars memorabilia, look for the Seiko Brightz SDGA005 LE solar digital for roughly the same price as an LE Astron.