Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[JimH]

I've been wondering what the energy consumption is for watching a movie on an HTPC vs. driving 5 miles to get a DVD and watching it on the same TV vs. driving 5 miles round trip to watch it in a theater.

There are a lot of variables, I know.  Is the movie downloaded from the Internet or ripped, etc.

It just seems like the 5 mile drive is a killer.  Even at 40 miles per gallon, it's .125 gallons of gasoline.


Wikipedia says:

"The ratings are based on EPA's formula, in which 33.7 kilowatt hours of electricity is equivalent to one gallon of gasoline..."

[rjm]

This type of question about things we do in everyday life is important and is one that we will have to think more about in the future.

One way to answer the question is to use the fact that wealth is proportional to energy consumption. More specifically, $1 US (1990) = 9.7 mW.

So for each of your 3 scenarios, estimate your total cost, convert to 1990 US dollars, then convert to energy as above.

[JimH]

One way to answer the question is to use the fact that wealth is proportional to energy consumption. More specifically, $1 US (1990) = 9.7 mW.

I've seen this type of "fact" stated by environmentalists before, but I don't see it.  If I spend $1, I might spend it on a solar panel or a bike, not on heat or on an airplane trip.  If I pay you $1, I might pay you to run a bulldozer or dance.  They all have different impacts.  $1 spent on condoms goes a long way to solving global problems.

I'll probably split this because I can see it might attract a crowd.

[KingSparta]

also consider walking into a theater where your feet stick to the cement because of all the spilled soda, and no body cleaning, people talking, and having to fight with the person next to you for your arm rest let alone the guy in front of you is blocking your view and the only thing you can see is the back of his neck.

[rjm]

It was derived by a physicist who modeled the economy as a thermodynamic engine. He wrote one of the most important papers ever. Most academics seem to ignore him. The conclusions from his work are very uncomfortable.

http://www.inscc.utah.edu/~tgarrett/Economics/Economics.html

[mwillems]

I've been wondering what the energy consumption is for watching a movie on an HTPC vs. driving 5 miles to get a DVD and watching it on the same TV vs. driving 5 miles round trip to watch it in a theater.

There are a lot of variables, I know.  Is the movie downloaded from the Internet or ripped, etc.

It just seems like the 5 mile drive is a killer.  Even at 40 miles per gallon, it's .125 gallons of gasoline.


Wikipedia says:

"The ratings are based on EPA's formula, in which 33.7 kilowatt hours of electricity is equivalent to one gallon of gasoline..."

There are a lot of variables, but assuming your formula for gas usage to power is correct, the gas equivalent is a little over 4 KWhs.  It would be possible to use 4 KWhs watching a movie in a Home Theater setup, but I think  you'd need a "worst case" power consumption profile.  If you assume a 2 hour movie, you'd need to be using 2000 watts for two hours.   A very large plasma TV (which is the most power consumptive of the three mainstream varieties) uses about 350 watts; a really robust PC power supply might have the capacity to put out between 800 and 1200 watts, but it's pretty unlikely that you're using anywhere near that much for any length of time in the PC (my understanding is that an average PC under heavy load uses between 180 and 360 watts). 

Which leaves the speakers, and obviously amplification can be more or less efficient depending on amp design.  The amp will often consume a fair amount just sitting idle; it depends on their topography, but I've seen receivers that burn 30 watts at idle all the way up ones that burn 200 watts just sitting, not to mention Class A amps. In most amp designs that I've interacted with, at normal listening volume you're probably losing more to the amp's idle losses than you're burning in output.

With an "average" HTPC, an LED TV, and a Class AB amplifier rated to a few hundred watts, your power consumption is probably maxing out at four or five hundred watts, and may be significantly less.  A power sniffer will tell you exactly how much is being drawn if you want to run it down.

It seems to me like driving anywhere is going to be more energy expensive than watching at home (assuming a system that isn't extremely energy hungry).  Downloading the film obviously adds energy costs for servers and transmission, but the DVD you'd be driving to buy didn't grow on the shelves in the store either so there's an energy cost there too, and theaters use a fair bit of energy as well (but there's probably a savings because so many people are watching together). 

It's hard to run down all the intangibles, but I think watching a film at home is a better bet than driving five miles to see one. Now biking to the theater on the other hand is a different story entirely 

[6233638]

With an "average" HTPC, an LED TV, and a Class AB amplifier rated to a few hundred watts, your power consumption is probably maxing out at four or five hundred watts, and may be significantly less.  A power sniffer will tell you exactly how much is being drawn if you want to run it down.

For what it's worth, my LED Backlit TV draws about 50W on average (local dimming combined with backlight scanning basically halves the power consumption and improves the image dramatically) and my HTPC - which was originally built as a gaming PC, and now has drives connected to all 8 SATA ports - draws about 80W during video playback - that would be significantly less if I were using something like an Intel NUC for playback - less than 10W.

I've actually been thinking about switching to something like a Mac Mini or a NUC for playback once Haswell is out, as long as the new GPU is capable of handling Jinc 3 AR scaling inside madVR.
My only issues with them are that the Mac Mini no longer has an optical drive, and the NUC uses an external power brick. No optical drive with the NUC either, but I'm sure someone probably makes a case you can put a NUC and an optical drive in.

I think you would have difficulty reaching 500W in most people's home setups even. The exception might be if you are using a projector.

[JimH]

I think you would have difficulty reaching 500W in most people's home setups even. The exception might be if you are using a projector.

500 watts per hour?

[mwillems]

For what it's worth, my LED Backlit TV draws about 50W on average (local dimming combined with backlight scanning basically halves the power consumption and improves the image dramatically) and my HTPC - which was originally built as a gaming PC, and now has drives connected to all 8 SATA ports - draws about 80W during video playback - that would be significantly less if I were using something like an Intel NUC for playback - less than 10W.

I've actually been thinking about switching to something like a Mac Mini or a NUC for playback once Haswell is out, as long as the new GPU is capable of handling Jinc 3 AR scaling inside madVR.
My only issues with them are that the Mac Mini no longer has an optical drive, and the NUC uses an external power brick. No optical drive with the NUC either, but I'm sure someone probably makes a case you can put a NUC and an optical drive in.

I think you would have difficulty reaching 500W in most people's home setups even. The exception might be if you are using a projector.

I agree, most people wouldn't ever get close to 500 watts; my setup draws in the high two-hundred watt range total (TV, PC, and amps) when watching a movie. My amps are unusually efficient (24 watts total idle losses for four channels), but my PC rig uses about twice what yours does under video load.  

Using a more power efficient PC would definitely take the biggest bite out of the footprint, but I haven't seen integrated graphics that can do Jinc (even with a dedicated GPU, my setup can only handle Jinc for one of the two scaling options, both pushes it over the line).   Based on your power figures, I may just need to upgrade my rig :-)

500 watts per hour?

One watt-hour is one watt drawn for an hour.  The gasoline equivalent was measured in Kilowatt hours; to get to 4 Kw hours, you'd need to be using a sustained 2000 watts for a period two hours (the length of a film).  Think of the wattage as an instantaneous measure of the rate of the flow of power (how fast is the water coming out of the hose); without a time measurement over which the power is flowing (how long did you leave the hose on) it doesn't tell you much about consumption.

A home system would be unlikely to draw 500 watts at once for any length of time (much less two hours).  My system for example would use about five or six hundred watt-hours over the course of an entire movie, it sounds like 6233638's would use even less.  So about 1/8 as much power in my case as driving five miles.

[kstuart]

It was derived by a physicist who modeled the economy as a thermodynamic engine. He wrote one of the most important papers ever. Most academics seem to ignore him. The conclusions from his work are very uncomfortable.

http://www.inscc.utah.edu/~tgarrett/Economics/Economics.html

[Feel free to split this out as a separate thread if desired.]

I skimmed through that paper ... it seems to operate on a number of unexamined and unnoticed assumptions - like most papers on the subject.

Money is a measure of human attention.

For example, the "goods and services" dichotomy is meaningless.  If you are building a car, you have employees who build the car, and you have parts coming in.... but... those parts are built by workers from raw materials... but ... those raw materials are mined from the ground by workers.  If there are no human beings spending their time paying attention to mining, then there are no raw materials, irrespective of who "owns" the land.

And owning the land simply means that people pay attention to your claim that you own it.  The fact that Native Americans lived there 500 years ago is irrelevant, because people pay attention to your Title claim and not theirs.

People go to movies that get the most attention, and those get the box office receipts.  Actors get larger contracts because their name gets more attention.

Conversely, if you do a really horrible thing and are constantly mentioned on CNN, you will get a book contract for more than any of us are likely to make in our lifetimes - because you have accumulated attention.

Then, once you have money, you can trade it back for attention.  If you are wealthy, you can hire a cook, a maid, a personal trainer, a driver, a valet, etc.   A poor person has to do everything themselves and usually cannot get any attention when they have a problem.

---

Regarding energy, the universe is full of it and not much else.  If sufficient human attention is paid to accumulating energy, there will never be any lack of availability.

[Samson]

I've been wondering what the energy consumption is for watching a movie on an HTPC

...the answer of course is it all depends on how much you eat during the movie ! ....have I misunderstood the question,lol sorry , couldnt resist