Probably none.
For energy sensing (current sensors), you have some serious rewiring to do. You also need a supply for each device. The ESP would be the only practical solution for this many appliances, if you have WiFi everywhere in the house.
For monitoring alone, your device would be made up of:
- Clamp on current sensors (not cheap), a current transformer + circuit, or a shunt circuit/board
- ESP micro-controller for WiFi connectivity
- Any adapter for 5V supply
However, there are much cheaper and easier ways to monitor (and also control) appliances:
- Ready made smart switches with their own dashboard/app and energy monitoring tools.
- SONOFF with
espurna firmware that has some fancy features like Alexa, IFTTT, OTA updates.. but no energy monitoring, only status.
If you have a big house or complicated equipment, it would be better to call a home automation specialist with an expensive Lora/Zwave/yourflavor solution.