Microgreen Program Expenses
The Grow Rack
A grow rack is the apparatus used for the growing of microgreens in a vertical format with a minimal footprint on the ground.
It consists of a 6-level chrome rack, with LED grow lights above each of the 5 lower levels. The lights are controlled with a timer that controls the amount of light the microgreens receive throughout the day. Also on each level is a small fan to circulate the air over the microgreens. The fan is also attached to its own timer, so that the fans can be intermittently activated, rather than being on full time.
Each level on the rack holds 4 trays of microgreens, for a total of 20 trays on each rack. Each grow tray is composed of 2 separate trays, one with holes in the bottom, and one without holes. Soil or other growth medium is held in the tray with the holes, which is then held in the tray without the holes. The holes allow the growth medium to drain water and be collected in the lower tray without the holes.
As you can image the cost of a grow rack is not insignificant, but once assembled, the rack will last for the entire life of the program.
Actual Cost of a Grow Rack
Operating Expenses for a Grow Rack
Operating a microgreens grow rack generates ongoing expenses. These expenses include electricity for the lights and fans, soil or other medium to grow the greens in, and the seeds to grow. Each tray takes about 2 weeks to grow and then needs the soil replaced and be reseeded. Electricity consumption is from the 40 watt grow lights and fans which are in operation for about 18 hours a day.
Seed Cost:
In general each microgreen tray will need about 50 to 200 grams of seeds, at least 2 times per month. That equates to about 5 kg of seeds a year for each microgreen tray that is in production. So an entire rack of 20 trays uses up to 100 kg of seed a year. As you can imagine seeds are very expensive so this is not an insignificant expense.
In general each tray will need about 50 grams of seeds, 2 times per month, at $25.00 per kilogram of seed, that results in a seed cost of:
$2.50 per month per tray
Electricity Cost:
As you can imagine electricity is one of the major ongoing costs of operating a growing rack, since the lights are on for at least 18 hours a day and the fans are on intermittently depending on the ventilation needed.
A 40 watt light shines for 18 hours per day for 28 days per month, resulting in 20.16 Kilowatt-hours per month and at a rate of $0.26 per kilowatt-hour totals $5.24 per month, and that covers 4 trays, that results in:
$1.31 per month per tray
Growth Medium Cost:
1 bag of soil is enough for about 10 trays, and each tray needs to be filled 2 times per month. That equates to about 2.5 bags a year per tray, or about 50 bags of soil for a complete grow rack each year.
There are non-soil alternatives such as coconut media mats, or locally sourced hemp mats from Drayton Valley which are organic and fully compostable. The main drawback to these alternative growth mediums, is that they are generally significantly more expensive than soil, but more environmentally friendly.
Each mat costs approximately $2.00 and can be used once per tray, and each tray needs to be filled 2 times per month, that results in a cost of:
$4.00 per month per tray
Total Yearly Cost to Operate a Microgreen Grow Rack
Seed Cost: $2.50 per month per tray
Growth medium Cost: $4.00 per month per tray
Electricity Cost: $1.31 per month per tray
These 3 costs total $7.81 per month per tray
And with 20 trays per rack results in:
A yearly operating cost of:
$1,875 per rack per year
