In some cases, devices may require more power than a reasonably sized solar panel can produce. If the device doesn’t need to run continuously, a solar solution is usually still possible.
The simplest solution is to use a solar panel to charge a battery.
The battery can charge while the device is off, then provide adequate power when the device is on.
As long as the energy produced by the solar panel is greater than the average energy used by the device, the battery will be maintained.
Another simple method is to collect energy and then turn the device on once you have stored up enough to run the device. This pulse-like method works well with higher power consumption applications where the frequency that the device turns on is not critical.