There are more on the market, the truth is I haven’t spent much time searching since, the one you see in the picture, is the one that I have been using for over 4 years. This solar keyboard incorporates a panel in its upper part, which thanks to the light feeds a small battery also incorporated in the keyboard for normal operation.
Like I said, this is the keyboard I’ve been using for over 4 years, averaging 5-6 hours a day, so I can talk about its performance without being wrong. By the way, its price was, if memory serves, around $ 35-40.
The keyboard is wireless, with perfect signal, connection via Bluetooth to the device you want to connect, be it a computer, tablet or any other.
This is clear and I recommend that it is better to use a conventional keyboard, with a cable where possible to avoid the use of batteries, but in case you need a wireless keyboard to different reasons, I recommend a solar. You’ll forget about batteries forever. Remember those watches or calculators with a little built-in solar panel? Surely yes, you will remember that they hardly ever failed. Well, this keyboard is the same.
The built-in solar panel is able to generate enough power for the keyboard run for hours and hours without interruption, no direct light from the sun, it works perfectly with indirect light. In fact, the one I use has never been exposed to direct sunlight for 4 years.
As for its good functioning, as a keyboard, no problem too. The keys work like the first day and the connection to the computer is hardly ever lost. I could tell the keyboard works just fine, like the first day.
I use it with Android and with macOS.
My model is the Logitech K750, like the one you can see in the photo. New models are emerging, few in number, especially at Logitech. On its website, it always appears at salebut it seems like lately it’s hard to find any reviews that i have read. On eBay I saw it at more or less the price I bought it 4 years ago.
If you need a wireless keyboard, I recommend it.