Such a small solar panel will be a useful addition or basis for home-made devices.
The voltage of the socket allows you to create solar charging for cell phones without additional circuits for lowering. True, from one socket, the charging process will last a long time due to the small power of 1 W (about 170 mA), to increase the power, you need to buy several panels and connect in parallel.
For instance: To assemble a “powerful” charge of 6 W (1A), 6 such panels must be connected in parallel. You will spend about 600 rubles (~ $ 8.2) on such a charge.
Cost: ~ 78