Convert value from negative to positive in lovelace card

Configuration
1

Hello,
Did someone help me to convert negative value to positive in Lovelace Card?
The entity is sensor.produzione_power
This is my code:

type: vertical-stack
title: Shelly
cards:
  - cards:
      - entity: sensor.cosumo_power
        severity:
          green: 1
          yellow: 2000
          red: 4000
        type: gauge
        needle: false
        min: 1
        max: 8000
      - entity: sensor.produzione_power
        severity:
          green: 0
          red: 90
          yellow: 40
        type: gauge
    type: horizontal-stack
  - columns: 2
    entities:
      - entity: sensor.cosumo_energy
      - entity: sensor.produzione_energy_returned
    type: glance

Best regards
Stefano