In a forum contribution, Heltec just announced a new solar driven LoRaWAN gateway, available until Oktober 2020.
This would be interesting für all LoRaWAN outdoor activities in rural areas. But obviously there are some obstacles to be overcome.
"HT-M02S uses the latest SX1302 baseband chip, just completed the verification of the RF function last week, but there is still a long way to go. We hope that it can work 365 * 24, but HT-M02S may be deployed in Cold Antarctica may also be near the hot equator. Therefore, we must consider whether the light intensity in different regions of the world can provide enough power? How big is the battery? How to guarantee the life of the battery? Anyway, we believe our team can make that happen!"
Probably, we only guess, it will be well related in some sort to HT-M02.