Saving on house lights electricity by using an LED flashlight

My MTE SF-23, a single LED single 18650 cell flashlight bought in 2010, pushing out a claimed max of 900 lumens (which a number of reviewers claimed was more like 3-400 lumens), with the kind of smooth transition between hot spot and flood that comes from an "orange peel" reflector, was my first flashlight that was bright and portable enough that I often carried it around the house, switching it on instead of turning on the light switch in dark halls and rooms. In a small room with the light bounced off a white ceiling it gave acceptable room illumination to read by.

Having that amount of easily portable light (and more with later flashlights) got me used to carrying it around the house to use when looking for things in dark places. I now often don't switch on the lights in brief visits to dark parts of the house to look for something. Not a great saving of electricity when those lights are just switched on and off when needed, but that's not how many people use house lights in dark winter evenings. A lot of lights in mostly unoccupied but often visited parts of the house are left alight all evening.

Suppose just for the sake of a simple illustrative example that this saves a conservative 50W for four hours a day. Over a year that amounts to 73 kwh, which in the US would cost around $9. So on purely economic grounds a general purpose domestic flashlight which lasts me five years and costs $35 is going to save me money. Of course your mileage may vary considerably.

No, I haven't forgotten the cost of charging it. That's what's technically called negligible in this kind of rough speculative calculation.

Welcome to the site chris.
I do the same thing. And sometimes after lights out I realize oops I forget X or Y then use a flashlight to go get it.

So you and I combined have saved $18. Possibly a wheelburrow load of coal not burned at the all night generator place....

Say 22 CPF'rs do this... $160+ saved and a loader bucket of coal not burned. Just think if 22,000 folks do this... and that is not an unreasonable number in my estimation.

Good post bro. Good post.

The high tech version is coming with responsive street lights and house lights that turn on with a human presence and back off when they leave.

Our neighborhood grocery store has LED lighting on motion sensors in the frozen food aisles. Great idea and so simple to implement! Going to have to try using my torches more around the house.

Robert

Same here. Evening time rolls around, there is a headlamp or a flashlight nearby. Kitchen and bathroom are pretty much the only lights used. Wife uses more lights around the house; her choice. She will use a Pak-Lite or a Nitecore TIP CRI on a Nite-Ize headstrap reading/writing late at night.

One should also consider wear and tear on bulbs that are turned on and off, as well as the constantly running lights getting worn out. Our most used lights now sport LED bulbs and we feel that they can be turned on and off without incurring accelerated wear. As more fluorescent bulbs in the house burn out, we will replace them with LED's. We only have a couple incandescents at this point. But there is no way I can say flashlights pay for themselves with this use. Got way too many.

tanakasan said:

Our neighborhood grocery store has LED lighting on motion sensors in the frozen food aisles. Great idea and so simple to implement! Going to have to try using my torches more around the house.

Robert

Click to expand...

I've done this in my kitchen, hallways, basement, garage and porches. It's certainly convenient and when it comes to forgetful minded persons and children, they're sure to save money.

The good news is that you are indeed saving money, the bad news is that it's probably less than 10% of your electric bill, especially if you ever use air conditioning. Move that thermostat up a couple of degrees in the summer and you'll save far more than living in the dark.

eh4 said:

The high tech version is coming with responsive street lights and house lights that turn on with a human presence and back off when they leave.

Click to expand...

The Philips HUE system can do this when paired with the optional Motion Sensor, which can turn a light or groups of lights on/off as you enter/leave an area.

StarHalo said:

The good news is that you are indeed saving money, the bad news is that it's probably less than 10% of your electric bill, especially if you ever use air conditioning. Move that thermostat up a couple of degrees in the summer and you'll save far more than living in the dark.

Click to expand...

True, especially if you live in a place like Texas.
I have some family in Vancouver and some buildings, mostly older, don't have AC duct work - maybe in circumstances like this it would be more relevant. I still think appliances like a refrigerator would use a lot more electricity than your lights.

StarHalo said:

The Philips HUE system can do this when paired with the optional Motion Sensor, which can turn a light or groups of lights on/off as you enter/leave an area.

Click to expand...

Having some Hue bulbs in my house I can't help but wonder sometimes how much power they use just to stay connected to the Hue bridge while not outputting any light.
I read in some sources that the consumption when off is about 0.4 W and when on it is 9 W. Given that I was using a 75 W incandescent before it would seem that the consumption when off is fairly inconsequential.
Although given the irregularity of my usage of my Hue lights it might just be better to go with CFLs...

When you take into account the cost of the charger, and the electrical cost of recharging your savings go down some. And yes, turning incandescent and fluorescent lights on and off wears them out. The primary point of failure of both is the startup process, something that LED lights don't have. So if you replace all your current bulbs with quality LED replacements you need not worry about how often they get turned off or on. I say quality, because the really cheap replacements get a good part of their cost savings from using lower quality parts in the driver circuitry, which leads to premature failure.

Imon said:

I read in some sources that the consumption when off is about 0.4 W and when on it is 9 W.

Click to expand...

9W at full output, but dimming reduces that number exponentially (the 0 on this chart is bulb "on" but dimmed as low as it will go, not bulb off):

Timothybil said:

When you take into account the cost of the charger, and the electrical cost of recharging your savings go down some. And yes, turning incandescent and fluorescent lights on and off wears them out. The primary point of failure of both is the startup process, something that LED lights don't have. So if you replace all your current bulbs with quality LED replacements you need not worry about how often they get turned off or on. I say quality, because the really cheap replacements get a good part of their cost savings from using lower quality parts in the driver circuitry, which leads to premature failure.

Click to expand...

I've been slowly converting my house lights from incandescent to CFL, and recently, from CFL to LED, and even more recently, some of them to LED with sensors which turn them on a few minutes after they detect a moving heat source. Initially those sensor ones seemed like a great idea, but now after a year or two of using them, I notice that nearly all of them have died, whereas none of the other rather older and more heavily used LED lights in the house have died.

Is that cheap heat sensor and startup circuitry dying before the LED, or the greatly accelerated amount of turn on & off cycles revealing a previously unnoticed startup wear rate in the LEDs?

StarHalo said:

The good news is that you are indeed saving money, the bad news is that it's probably less than 10% of your electric bill, ...

Click to expand...

In my case it's certainly a lot less than 10% of my electricity bill, but that's not (in my case) the point. The point is to have a good answer ready when I get asked "That new flashlight looks expensive. How much did that cost us?"

chris malcolm said:

Is that cheap heat sensor and startup circuitry dying before the LED, or the greatly accelerated amount of turn on & off cycles revealing a previously unnoticed startup wear rate in the LEDs?

Click to expand...

I'm betting on the sensor. I used to have one of those 4w incan night lights with light sensor in my bathroom. Both of the ones I tried had the sensor fail long before the first bulb died.
I think it is something about photosensors in general. When I was on the board of our condo association I replaced several PAR light fixtures with HPS ones with built-in day/night sensors. I had one of those fail early as well.

First of all, that's a bit ridiculous. By the time you pay for the light, batteries, charger, and electric to charge the batteries you are losing money. Just flip the lights on and off and use LED bulbs if you want to save money.

Secondly, we are probably all a bit ridiculous. I enjoy doing the same thing. I just don't think I am saving money. 😀

Third, maybe my numbers are all wrong and we should all save money by using flashlights more. The more I think about it the more likely that seems. I

Received my D4! My first Emisar and first tail stander. Using it to light the room…just for fun!

Robert

tanakasan said:

Received my D4! My first Emisar and first tail stander. Using it to light the room…just for fun!

Click to expand...

You'll find [once the sun sets] with dark-adjusted eyes, a ceiling-bounced 100 lumens is about right for a family/dinner table situation, for just yourself doing a task 25 lumens is good, and just relaxing or doing something non-detail oriented 2 lumens is fine. For reading, directly pointing the light at your reading material needs only 0.01 lumens. Anything more than these values just puts more light on what you can already see, which uses more battery than you need for the task. All of which sounds like novel energy-saving factoids until the power goes out, and then knowing how little you can get by on to prolong your battery supply suddenly becomes very important..