NRDC - Home Idle Load: $8 Billion/Year wasted - Page 1
Forum section: electronics / general

author: Zucca
author_rank: Unknown
timestamp: May 11, 2015, 10:56:40 am
content: http://www.nrdc.org/energy/files/home-idle-load-IP.pdfthe classic red LED costs so much???

author: Mechanical Menace
author_rank: Super Contributor
timestamp: May 11, 2015, 11:17:56 am
content: Quote from: mojo-chan on May 11, 2015, 11:01:25 amTBH though a lot of what in Japan would be an advertised feature just isn't seen as worth advertising outside of Japan. Apart from my white goods I haven't purposely shopped for energy efficient products, I've accidentally ended up with them just due to upgrading.

author: madires
author_rank: Super Contributor
timestamp: May 11, 2015, 11:56:50 am
content: And this topic really matters! We got insane prices for power, e.g. 10W 24/7 cost me EUR 27.93 per year. Cheap wall warts burn a lot of power caused by poor efficiency, and it adds up. I moved nearly all my communication/networking stuff from wall warts to a central high-efficiency PSU with DC-DC converters for the required voltages and the power consumption went down to about 50%!

author: Zucca
author_rank: Unknown
timestamp: May 11, 2015, 12:26:57 pm
content: Quote from: madires on May 11, 2015, 11:56:50 amCongrats! Can you give a little bit more of details? What communication/networking stuff are you talking abot? Server and Telephones? And what are the voltages at the inputs and outputs of your high eff. DC-DC converter? Do you have maybe multiple line with different DC voltage running in the walls?Just curious...

author: madires
author_rank: Super Contributor
timestamp: May 11, 2015, 12:59:51 pm
content: Quote from: zucca on May 11, 2015, 12:26:57 pmActually it's very simple. The central PSU is a 80+ Gold ATX PSU which is already powering a server. It has the typical design with a 12V secondary and DC-DC converters for 5V and 3.3V. I've also added an or-power option with another ATX PSU in case the server needs some maintenance and is powered down. The communication/networking stuff is located in the same room as the server, i.e. simple wiring. For the power distribution I took a nice box, added fuses, some switches and a lot of connectors. You could go for 4mm banana or 2.1/2.5mm barrel connectors as used by most devices. A lot of the stuff can be powered by 12V directly and for other required voltages I've build some DC-DC converters, like 7.5V or an isolated one for the DECT. I don't have any special stuff, just the common devices. i.e. router, desktop switch, DSL modem, telephones, VoIP-ATA (I'm VoIP only, PC speakers (with an additional power filter), LED desktop lamp and so on.

author: Zucca
author_rank: Unknown
timestamp: May 11, 2015, 01:12:47 pm
content: Quote from: madires on May 11, 2015, 12:59:51 pmThanks, very interesting. What I was imagine is not too far away from reality. When they will switch from AC to DC in the home mains? Never I know... sad...

author: wraper
author_rank: Unknown
timestamp: May 11, 2015, 01:23:33 pm
content: Quote from: zucca on May 11, 2015, 01:12:47 pmFor what reason?

author: Zucca
author_rank: Unknown
timestamp: May 12, 2015, 07:08:44 am
content: Quote from: wraper on May 11, 2015, 01:23:33 pm1) Less losts on the line2) An AC2DC converter is less efficient than a DC2DC oneAt least it is what they told me and it makes sense in my small brain. Of course 3 Phases motors will be a PITA to runs fomr a DC since you need a converter.I am still convinced if there was no electric power network they will start with a DC system today.Anyway I am open to learn something, please open my eyes if I am wrong (I´m not attacking you, just want to know if I am wrong).

author: miguelvp
author_rank: Super Contributor
timestamp: May 12, 2015, 07:16:41 am
content: How efficient is it to move DC to your home?Edit: but I digress, maybe it's time for DC on the grid:http://www.extremetech.com/extreme/142741-tesla-turns-in-his-grave-is-it-finally-time-to-switch-from-ac-to-dcBut I'm not sure how they handle the voltage drop over distance due to the transmission wires.

author: Zucca
author_rank: Unknown
timestamp: May 12, 2015, 07:22:26 am
content: It is not efficient, and it would be a stupid move for 2 reasons:1) all the products are designed to work with AC mains2) since the power incoming to my homes is AC, I would need a big ass AC2DC at the beginning: $$$$$$!I am just saing, a DC power distribution network would be more efficient than an AC one.Somebody told me they are now designing a DC power distribution networks in ships (at least for certain power devices, I have no details sorry).

author: Delta
author_rank: Super Contributor
timestamp: May 12, 2015, 07:24:04 am
content: Quote from: zucca on May 12, 2015, 07:08:44 amSay whaaaaat? Have you been inhaling flux fumes?

author: Zucca
author_rank: Unknown
timestamp: May 12, 2015, 07:26:16 am
content: Quote from: Delta on May 12, 2015, 07:24:04 amUnfortunately yes... it happens very often. Thanks for your very constructive feedback and support to this forum.

author: dexters_lab
author_rank: Unknown
timestamp: May 12, 2015, 10:16:37 am
content: Quote from: Mechanical Menace on May 11, 2015, 11:17:56 amit's interesting how their electrical system can make designs that everyone should adopt because it's more efficient.all of the kettles i saw in Japan are electronically controlled and properly insulated, with only 100v or so to work with they have to be... it's crazy that our western kettles dump kw of energy into water and then release it through sides! Not to mention merrily boiling away while some bi-metallic strip from the ark lazily decides it might want to turn the switch off

author: Mechanical Menace
author_rank: Super Contributor
timestamp: May 12, 2015, 10:50:02 am
content: Quote from: dexters_lab on May 12, 2015, 10:16:37 amAnd that's different to here how? You may still get the odd idiot who won't replace their 20 year old shite but that's getting rare. Japan is also just above us on the average power usage per home (5513kWh vs 4648kWh) so we're obviously doing something better.

author: rolycat
author_rank: Super Contributor
timestamp: May 12, 2015, 11:11:10 am
content: Quote from: dexters_lab on May 12, 2015, 10:16:37 amIt's not that crazy - a kettle only takes a few minutes to boil, and the heat loss during that period won't amount to much. Similarly, even if it takes 15 seconds to turn off after it begins boiling, the additional energy used is relatively small. If you boil such a kettle ten times a day the wasted energy is about the same as a permanent 5W load.

author: madires
author_rank: Super Contributor
timestamp: May 12, 2015, 11:18:37 am
content: Quote from: zucca on May 12, 2015, 07:22:26 amDC at mains voltage is already in use by a few datacenters. When you consider the whole power system, including UPS, ton's of PSUs in servers, routers, switches and optical transport, and air conditioning of course, the DC system is about 10% more efficient. 10% of a datacenter's power bill is a nice sum.

author: ciccio
author_rank: Frequent Contributor
timestamp: May 12, 2015, 11:26:36 am
content: I'm not an electrotechnical engineer, but I'm not sure that converting the (existing) power distribution grid to DC could be a wise operation, not even a cost effective one.Transformers in the grid are very efficient devices and have the bad habit of lasting lots of years. Should we send them to recycle (a dumpster somewhere in Africa or Asia) and spend money for new equipment? Somebody will be happy: the converter manufacturer--The converters (from hi voltage lines to mid and low voltage lines) will be electronic, with the associated reliability issues.It's the same with wall warts: the old ones, with laminated core, 50 Hz transformers, if correctly and not too cheaply designed, will outlast all the new switching units. I have examples of standard low-power supplies (one is powering my condo's door bell system) that are operating, 24/24, from the 80's.Best regards

author: Zucca
author_rank: Unknown
timestamp: May 12, 2015, 11:42:54 am
content: Quote from: ciccio on May 12, 2015, 11:26:36 amWhen I was living in USA, one day I saw the lights in my apartment acting in a funny way: the brightness was just crazy. Mmmm... I pulled out the DMM and the mains were at 160-200 VAC and not 110VAC. One AC/DC converter melted in my home (was not capable of 220VAC) but the rests of them survived quite nicely (they were designed for both 110/220VAC). I cut down the power and went to work, when I returned everything was fine and repowered my home.Transformer can fail, the interesting question is if a WELL DESIGNED DC/DC converter could have the same life time or comparable (probably not my guess). There are tons of DC/DC on the market designed to be cheap... and they don´t last long, so statisticallycicciois right but I think the build quality and design specifications play a very important role here.

author: wraper
author_rank: Unknown
timestamp: May 13, 2015, 07:29:06 am
content: As for implementing DC power consequences:* You can no longer use all of your linear power supplies or bench multimeters. Replacing Transformer with SMPS will make them comparably very noisy.* You can no longer run any appliances that have brusheless motor inside. All you can run directly are brushed DC motors.* Triacs no longer work for controlling power.* 3 phases no longer work, so you will need thicker wires to distribute the same amount of power.* You would need separate power line to run 3 phase motors (anywhere where you need high power motor) or use very expensive converters.And overall. To convert from AC to DC you need just a diode bridge + capacitor (or no capacitor if pulsed is OK) or PFC for better power factor. To convert from DC to AC you wold need to do much more complicated things.

author: dexters_lab
author_rank: Unknown
timestamp: May 13, 2015, 07:54:13 am
content: Quote from: rolycat on May 12, 2015, 11:11:10 ami'm talking about the retention of heat after it's boiled, not during. Those people who click the kettle on, walk away, come back 5 mins later and reboil it because it's not retained it's heati'm illustrating the point that you can make even small savings, it may not sound much but how many times is a kettle boiled in the UK every day? I have no idea but it's going to be in the order of millions, if it was just a few watts for a few seconds each time i agree it would not make much difference but they are normally in the region of 2-3kw. When you start adding up the effect from millions of instances every day in every country it will make a difference.

author: Mechanical Menace
author_rank: Super Contributor
timestamp: May 13, 2015, 09:47:13 am
content: Quote from: mojo-chan on May 13, 2015, 07:57:13 amBut still use over 1000kWh per household more than us per year, in a country with much more single person households, so while they may have better Hoovers etc they're obviously getting something wrong we're getting right. The Japanese don't have all the answers and nobody else has any, they aren't the master race, we've got shit to learn from them and vice versa.

author: dexters_lab
author_rank: Unknown
timestamp: May 13, 2015, 10:03:24 am
content: Quote from: Mechanical Menace on May 13, 2015, 09:47:13 ami dont think anyone said they were a master race, i'm pointing out that sometimes everyday products in other parts of the world are better than our own

author: rolycat
author_rank: Super Contributor
timestamp: May 13, 2015, 10:10:30 am
content: Quote from: Mechanical Menace on May 13, 2015, 09:47:13 amI'd guess a lot of that extra usage is down to heating costs. Japanese homes are typically poorly insulated compared to their Western equivalents and lack central heating, so they use a lot of electrically heated tables (kotatsu) and electric space heaters.

author: AdShea
author_rank: Contributor
timestamp: May 15, 2015, 04:56:11 pm
content: Don't forget the big problem with in-home DC distribution: Fuses and breakers get way more expensive (DC arcs don't self-extinguish every few ms). Also failing wiring and interconnect is near silent rather than buzzing.