Background
Dust on solar panels reduces power output, and in large fields manual cleaning is slow and expensive. The client developed an automated cleaning system and needed the electronics and communication to run it.
The challenge
A solar field is a large open area, with no Wi-Fi and sometimes poor cellular coverage. Every cleaning unit has to receive commands, report its status and work for years in heat and dust.
What we built
- A controller for the cleaning unit: motor drive, sensors and protection.
- A LoRa network: long-range, low-power communication between the end units and the central controller.
- A master board: the site's central controller, connecting all cleaning units over LoRa and the whole network to the server over Wi-Fi. The master board page.
- Server connection: cleaning schedules, fault reports and tracking of every unit.
- Remote updates: the firmware of the whole system can be updated without visiting the field, including the end units on LoRa. The LoRa channel is very slow, and regulations allow transmitting only 1% of the time. So the update is broadcast to all units in parallel, at a rate that stays under the limit, and only missing parts are re-sent. About the update mechanism.
The result
A system that manages the cleaning of an entire field remotely, with no communication infrastructure in the field, and receives new versions without a site visit.
