Electricity for lighting is the most expensive part of growing marijuana indoors. Indoor growers tend to use HPS and MH bulbs both of which use relatively large amounts of electricity. LED lights use much less power.
Alice will have an advantage over Bob if she makes intelligent choices about her lighting fixtures, growing cycles, etc. Lower operating costs, higher profits.
Electric rates are often a fixed cost per kilowatt hour: cost in KWH x total wattage x hours
The Electricity Rate Calculator spreadsheet is available as a Google Sheet and as an Excel spreadsheet.
We encourage growers to use the Electricity Rate Calculator to not only keep track of the power they’re using now but to plan future purchases with electricity costs and the associated carbon footprint in mind. This spreadsheet is useful when comparing different light sources (HPS, MH, CFL, LED, etc) or different lighting cycles. It’s a modest attempt to help growers use less electricity, save money, and reduce their carbon footprint.
The time intervals (18 & 12 hours) represent the common daylight cycles for growth and flowering respectively. Different light cycles have an impact on your electric bill. See how much you’ll save by flowering at 11/13 vs 12/12, even when you account for a longer flowering time using a shorter daylight cycle.
If your plants are night owls they’ll help with load balancing. Ideally consumer demand should be even throughout the day but it isn’t. Most electricity is used during the daytime. Less of a utility’s generating capacity is used at night. Do your part by setting your timer so your lights come on when demand is low.
We want any & all feedback. What would you like to see it do or not do?
The Electricity Rate Calculator is free software released under a Creative Commons Attribution-ShareAlike 4.0 International license (CC BY-SA 4.0).