Indoor cultivation of marijuana takes lots of electricity, and mixed-light takes some.
Humboldt County, California, will decide in November on an environmentally friendly cannabis tax. The rates are:
$1 per square foot for outdoor cultivation area,
$2 per square foot of mixed-light cultivation area,
$3 per square foot of indoor cultivation area.
Text of the proposal is downloadable at https://humboldt.legistar.com/LegislationDetail.aspx?ID=2807214&GUID=851B7280-CBDD-4573-A5EC-4C9BAC8DB874&Options=&Search=
Press report of approval is at https://lostcoastoutpost.com/2016/aug/9/supervisors-vote-unanimously-place-pot-tax-measure/.