as specified in https://github.com/SignalK/specification/blob/master/schemas/groups/electrical.json the yieldToday value should be in Joule, but the BLE data contains the daily energy yield in Watt-hours, not in Watt-seconds (aka Joule), so the value returned by the BLE code needs to be multiplied by 3600 before being pushed to SignalK.
as specified in https://github.com/SignalK/specification/blob/master/schemas/groups/electrical.json the yieldToday value should be in Joule, but the BLE data contains the daily energy yield in Watt-hours, not in Watt-seconds (aka Joule), so the value returned by the BLE code needs to be multiplied by 3600 before being pushed to SignalK.