Energy & power metering

1. Wire your RS485 energy meters to a gateway and add each as an rs485 device, mapping registers (voltage, current, kWh) to tags.
2. Use a line-chart for power trend and a kpi-card for today's kWh.
3. For totals across meters, use a computed widget summing each meter's power tag.
4. Add a rule on current > rated_amps to catch overloads.

For long time ranges, prefer the rs485-query data source so the backend buckets history efficiently.