Cost-effectiveness of DIY lettuce with grow lights

I suggested to dad we compute the cost of our DIY grow lights (for growing lettuce) and see if it’s cheaper than buying at the store.

“Why in the [censored] should I care if it’s cheaper?” He said.

“Cuz then you might as well buy it in the store,” I said.

“You’re missing the point son. I ain’t growing my own lettuce to save money. I’m growing my own lettuce so when the [censored] hits the fan, I’m not eating spam and dog food, waiting my sorry [censored] in a government-sponsored shelter, hoping the Red Cross or FEMA or the Mormons come ‘n save me from going all Donner party on my neighbors. Thanks, but no thanks. I’ll grow my own lettuce.”

(I wanted to point out he’s still relying on “capital cronies” to supply the electricity, but then I’d a had an hour long lecture on how, any day now, he’s going off grid and how I need to prepare to start crapping in an outhouse.)

So, I installed a Kill-O-Watt (affiliate link) to figure out how much the electricity’s costing us. Sure, I could look at the specs off the shop lights and use their usage ratings. But, I guess a little of dad has rubbed off on me and I don’t trust those crony shop light manufacturers.

So, I plugged the thing in and hit the kwh (kilowatt hours) button.


Two days later, I checked the reading:


So, .91 kwh over two days, or .455 kwh per day. Here, we’re charged 13 cents per kilowatt hour, so that’s costing us 5.9 cents per day.

The package says they’re ready to harvest at six weeks. So, a little math:

6 weeks x 7 days x 5.96 cents = $2.50.

And the grocery store charges us $1.49 for a head of lettuce.

Well that sucks.

Except…

That’s one head. We’re hoping this thing will yield 4 heads total, or 63 cents a piece.

Not bad.

If it works.

I’m still not sure it will.

(By the way, if I used the watt ratings on the box, it estimates I’d spend $4.19 over a six week period, so it was overestimating by almost 100%. Good thing I didn’t trust those crony capitalists, eh?)



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