[Symbiote]

  GNU Units version 2.19
  with readline, with utf8, locale en_IE

and no customizations.

  units '500W * 1 year * 0.20/kWh' '1'

would also work.

[anthk]

Do you have a custom ~/.units file?

    user@xirl>units '500W * 1 year * 0.20/kWh' '1'
        * 876.58128
        / 0.0011407955