Discussing starting plants indoors for the past couple days got us thinking about the cost of that endeavor...
The first big cost is electricity to run the lights, heat mats, and fans. For the main set-up the fluorescent lights use 320 watts. The lights are on a timer for 14 hrs a day. The 4 heat mats consume 17 Watts each and are on 24 hrs a day. Lastly the 2 air circulation fans each use 13 Watts and are on continuously. The total electricity use then comes to 6.73 KW pr day.
For the secondary set-up the fluorescent lights use 240 watts. The LED light consumes 100 Watts. Both lights are on for 14 hours each day. The heat mat consumes 107 Watts and the two fans add another 13 Watts each. Just as with the other set-up they are in continuous use. The total for the secondary set-up then comes to 7.95 KW pr day.
Running both set-ups then consumes 14.68 KW pr day. Over an average month that's 446 KW. Electricity costs average just slightly less than $0.09 pr KW in our area. The total average monthly cost then is $40.00, with $18 of it going to the main set-up and $22 going to running the secondary set-up.
This year we are doing some experiments with the secondary set-up but normally the secondary set-up wont need to be on until the 1st overflows with plants at the end of March. The first seedlings were started a couple days ago in the main set-up and it will run until planting time in mid May. That means main set-up will run for 3 months and the secondary set-up will run for a little less than 2 months.
The electricity cost of starting our seedlings will be about $98.
If we add the other costs we've spent $140 for the heating mats, $120 for the LED light, around $150 for the fluorescent lights and another $100 on timers, tubing, trays and the like. A total of $480 with an expected operational life of at least 10 years adds another $48 to the table.
A pack of seeds lasts a long time, and often seeds can be saved from the previous years crop with a little effort, but we still spend on average another $60 on seeds each year.
Come planting time we will have $206 invested in our seedlings for this year. While we could not buy seedlings for many of the variates of plants we'll grow, it will be interesting to go to the farmers market and see what it would cost to plant seedlings for similar plants. We'll be sure to update on that when seedlings start going for sale at the market!