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Why turning off the lights is a waste of your time

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nth_degree:
Alright I’m hoping someone on this forum can set me straight on a contrarian opinion I’m forming to piss off my math professor roommate. Here is the problem;

My irritating AF roommate follows me around the house turning off the lights everywhere I go and I’m living in darkness. I’m all for saving energy (I replaced all the bulbs w LEDs last year) but what he’s doing IMO is a repetitive task for dopamine payoff and virtue signaling. Little different to the behaviors encouraged by many religions. I’m thinking rosary beads. Anyway

I don’t think what he’s doing either saves energy or money. For one thing if you turn off the lights while it may slow the meter, if that energy isn’t stored it will still go to waste. And how about this; even if we use the economy bulbs the cost in average purchase consumer quantity of 16 is $35, so say $2 a piece. The energy cost of 24/7 operation at 11W is 12.50 a year here in Berkeley at 0.13KWH. Each bulb has a quoted MTBF of 15,000 hours but I believe the manufacturers are stating the LED MTBF not the driver MTBF there. For the bulb as a unit it’s the lower of course but the difference is if you frequently turn the power on and off the driver will have a significantly reduced life and your 13 years of service for $2 just became 10 months of service. So you lose $1.85, per bulb. Furthermore there was an energy cost to manufacturing every component of the bulb so there go your energy savings as well, if there ever were any.

I think turning off the lights was a 60’s habit to save money when incandescent bulbs were 150W and the cost of energy was sky high. I don’t think it ever saved energy either except in the sense that if the power station saw lesser demand collectively it would reduce the quota for an area and waste less in that sense.

Please tell me why I’m wrong

DrG:
By my analysis over the last few days, I have turned on my bathroom light 8 times and turned it off 11 times. I am surprised that the two numbers do not show greater agreement.

Could this be related to the pandemic culture war?

wraper:

--- Quote ---if that energy isn’t stored it will still go to waste.
--- End quote ---
Nothing will be lost since power generation is adjusted according to consumption.

--- Quote ---For the bulb as a unit it’s the lower of course but the difference is if you frequently turn the power on and off the driver will have a significantly reduced life
--- End quote ---
Unless it's a badly designed bulb, it will not significantly lose it's lifetime from frequent switching. Heat is what wears them the most. And running for a long time increases the temperature bulb experiences.

--- Quote ---MTBF of 15,000 hours
--- End quote ---
MTBF is not a lifetime. https://www.controleng.com/articles/learn-or-review-the-difference-between-mtbf-and-lifetime/

Capernicus:
What about the amount of power the industry uses compared to the "public civilian sector"  I bet its more than 1000x more power usage,  but I'm only guessing.

fordem:

--- Quote from: wraper on January 02, 2022, 01:50:03 pm ---
--- Quote ---For the bulb as a unit it’s the lower of course but the difference is if you frequently turn the power on and off the driver will have a significantly reduced life
--- End quote ---
Unless it's a badly designed bulb, it will not significantly lose it's lifetime from frequent switching. Heat is what wears them the most. And running for a long time increases the temperature bulb experiences.

--- End quote ---

Aren't you neglecting the impact of "inrush" current every time the lamp is powered on?  I switched to LED lighting around 2010/2011 and I've had about a half dozen or so bulbs fail, every one has been a driver failure, not the LEDs and it's on the LED end that the heat is being generated.

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