[scraft]

I heard this £30 saving stuff on the radio this morning, and it made me shake my head a little. I remember when I got a socket adapter that measures power consumption, and I went around checking all my appliances, eager to find out which are drawing lots of power, excited at the money savings. Started with my old, huge, plasma TV, that is the best part of 15 years old - surely chugging loads of power in standby? Nope, next to nothing. Monitors, same. Network switches, same. Essentially I didn't find anything in my property that was doing anything unexpected. Having hot water (which I get via electricity as my flat doesn't have gas) for a single day will use up more energy than I'd save unplugging all my devices. Similar for heating (again, electricity based) on a colder day in winter would cost more than all the standby devices.

I remember a long time ago (25 years?) someone 'invented' a device where you plug your TV into it, and it has an IR receiver to go with it, you program it to respond to your TVs power button (on the remote control), and then when you go to put your TV into standby, the plug then turns off too, and when you switch it on it does the opposite. At the time it was being touted as the money saver, and I got the impression (although never actually tested!) TVs back then did draw a lot in standby, so this 'invention' was a legitimately good one. But it didn't seem to really take off, I am assume because standby was rapidly implemented in a way where there is such minimal electrical draw that it would be pointless.

[spicyjpeg]

A nice side effect of people doing this is that, depending on where you live, you might be able to obtain these older, less power efficient devices for relatively cheap on the used market. Of course if you can barely afford electricity buying them is probably not a bright idea, but for someone with e.g. their own PV system it can be a great way to save some money while also reducing the amount of e-waste going to landfills.

Even better, this is not limited to large power hungry appliances. You can build a surprisingly decent gaming handheld out of an old flagship phone with the help of rooting and some hardware mods [1], basically taking advantage of the low resale value of Android devices.

[1] https://youtube.com/watch?v=px1A6XptqhQ

[bombcar]

And if you’re in an area that gets cold, waste heat isn’t so bad - in the winter.

[lkbm]

True, it's not a full loss. A heat pump can easily be 400% efficient, though, so I'd rather lean on that except in extreme cold.

Still, not a bad idea to run Folding@Home all winter.

[titzer]

IIUC you need a higher temperature source from which to pump heat, so in the winter, where do you get that temperature differential?

[jhenkens]

Thankfully, you are wrong about that! Just like you don't need a cooler source _from which to source cold_ in the summer with AC. Technology Connections has a fun (well, to me) video on how heat pumps work and are great. Literally just AC units running in reverse, thanks to having a valve.

https://www.youtube.com/watch?v=7J52mDjZzto

[extra88]

Yes, Technology Connections is a great channel and added a couple of new videos about heat pumps in the past month.

https://www.youtube.com/c/TechnologyConnections/videos

[bombcar]

At a certain temperature differential you need to source "heat" from elsewhere, which is why up north you either need a geothermal heat pump (underground piping) or you supplement with gas or electric heat.

Some very efficient pumps can work down to 0 degrees, but most start losing efficiency at 25 to 40 (Fahrenheit).

For some parts of the world, a heat pump is perfect - pump in heat in the winter and heat out in the summer, but when the outside temperature can hit -40º Fahrenheit (which is -40º Celsius), you're gonna need something else.

[outworlder]

For the overwhelming majority of the world they are perfect. Even in high latitudes, they might only reach those extremes for a few days in a year, that's when you would require a backup.

Losing efficiency is fine since they are so ridiculously efficient to begin with.

[lmt55]

This is not true, any more than your fridge needing a source of cold from which to cool itself down.

[ryankrage77]

The temperature differential is between the outside temperature and -273°C. There's still heat energy to be captured even on a cold day.

[mmcnl]

100% efficiency is rather low for heating. Heat pumps easily give you 400%. Efficiency in this case calculated as: generated energy (in heat) / electrical energy. Efficiency goes beyond 100% because heat is extracted from air or water.

[farias0]

A good rule of thumb, and I hope someone more knowledgeable can correct me if I'm wrong, is that stuff that generate more heat will consume more power. So hot shower, iron, curling iron, hairdryer, rice cooker, this kind of stuff. Electronics that generate minimal heat will consume minimal power in general.

[mort96]

In general, all the electricity consumed by an electrical device gets converted into heat. If your GPU uses 250W of power, it generates 250W of heat. If your whole computer draws 1kW from the wall, it generates 1kW of heat. If your little raspberry pi and its power supply together draws 15W from the wall, it generates 5W of heat. A 1500W electrical space heater converts 1500W of electricity into 1500W of heat.

So yeah, you're not wrong.

[saagarjha]

Only if it's not doing useful work.

[Gigachad]

It's just basic energy physics. Making something hot or cold is real work. Same with moving something or producing light. But light is extremely "cheap" compared to the rest. Computing data or rendering a video game isn't real work and would consume no power if it wasn't for the inefficiency of current flowing through the chip making it hot.

[atq2119]

If I remember my long ago physics classes correctly, irreversible computation inherently costs energy: you can't get its energy "consumption" down to zero because of entropy, no matter how efficient the technology. Our computer architectures are far from reversible in a physical sense. If they were, you could run programs in reverse. That said, the minimum amount of energy required is an absolutely tiny rounding error compared to the waste heat of today's technology.

[kqr]

And if the heat goes into water, it needs even more power because water is notoriously hard to heat up.

At one point I owned many appliances that leaked heat, and I think I learned to estimate how much power they drew simply by putting my hand on them and feeling how hot they were. I'm not sure I have that superpower anymore. (Obviously it was never that exact, because it depends on many other things like volume, material, isolation, etc. But you can get fairly close for common household things – between a finger and a few heads in size, surrounded by air, plastic case.)

[ballenf]

Or to put it another way -- if hot water goes down the drain (shower, clothes or dish washing, etc.), then that's another place the waste energy is going.

[firebird84]

Better down the drain then to radiate it back into your air. Then you gotta spend more energy pumping that heat outside (if you live in a hotter climate like I do).

[jhenkens]

Alternatively, use it to warm up the cold water coming into the shower (I'd guess the largest usage of hot water in a home). Warmer "cold" water mixing with the hot water means less hot water used out of the hot water heater. My understanding, placing this only on the cold supply to the shower is it'll only impact your showers. https://ecodrain.com/en/

[thow-58d4e8b]

Correct, and the difference is not even close - anything to do with temperature manipulation consumes orders of magnitude more. Literally, not figuratively

The laptop I'm writing this on consumes around 10W. Kettle 2100W

Making one coffee in the morning consumes enough electricity to power the laptop for the whole workday

The idle power consumption of my home is dominated by the fridge and freezer (around 150W combined). Idle mode of any other devices is a rounding error

[rhino369]

My power company sent me a power strip that has a somewhat similar feature. It constantly powers the TV, but the rest of the strip is turned off when the TV is off. It's so you won't waste power having Roku, etc., always running.

[darrenf]

> I remember a long time ago (25 years?) someone 'invented' a device where you plug your TV into it, and it has an IR receiver to go with it, you program it to respond to your TVs power button (on the remote control), and then when you go to put your TV into standby, the plug then turns off too, and when you switch it on it does the opposite. At the time it was being touted as the money saver, and I got the impression (although never actually tested!) TVs back then did draw a lot in standby, so this 'invention' was a legitimately good one. But it didn't seem to really take off, I am assume because standby was rapidly implemented in a way where there is such minimal electrical draw that it would be pointless.

I had a couple of these (in fact I probably still have them), from the 2000s - an Intelliplug and Intellipanel - the later being an 8-way plug. I used it for a TV, 5.1 amp/receiver, blu-ray player, Xbox360, Sky+, Wii, and Squeezebox Radio. The Sky+ box was in the "always on" socket so it could record stuff at all times, while the TV was in "if this comes on, turn on everything". I convinced myself I was doing a good thing for the planet and my finances, but I never measured it. Blindly believing it was far preferable to spending any effort on proving I'd been a fool, especially since I needed the sockets anyway - I don't recall the price being that much different to any other 8-way I looked at.

[dTal]

>if this comes on, turn on everything

Eco-friendly or not, I'm impressed; detecting power draw and using that as a signal is actually a legitimately clever solution to the problem of wanting to conveniently switch multiple things at once. The only caveat I can think of is that some devices probably don't like being switched at the wall.

[mercutio2]

I've found these devices to be finicky. You have to set the threshold of current flow that matches your TV, and sometimes switching from one input device to another will spike power consumption low enough to turn things off in a way you don't want.

But it is a very cool idea.

[mmikeff]

I thought the same, and my Smart Sony TV claims very low standby consumption, but when it is on the Wifi and sat there ready to Airplay too it consumes something close to 27W all night long. I setup a smart plug to turn it off at night on a schedule.

Also seen that my Hifi Amp draws a good few watts on standby.

We have recurring argument in my house where my partner tells me I should have turned the LED lights off to save electricity and I tell them to close the curtains to keep the heat in. In truth I have no idea which wastes more energy/money

[physicsguy]

They said £150 on Radio 4 this morning!

[nicgrev103]

Telegraph reporting £147 today https://www.telegraph.co.uk/bills-and-utilities/gas-electric...