This House Runs Entirely on DC Power
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- เผยแพร่เมื่อ 13 ก.ย. 2024
- Full story: engineering.pu...
Did you know there’s a silent war going on inside your home? Alternating current (AC) electricity comes in from the grid, but all of your appliances and lighting run on direct current (DC). Every time you plug something in, power must be individually converted from AC to DC, a costly and inefficient process. Purdue University researchers have proposed a solution to the problem by retrofitting an entire house to run on its own efficient DC-powered nano-grid.
Mechanical Engineering: purdue.edu/ME
Where's the DC appliances? This just looks like a solar system with typical inverter. Was expecting a rewiring to run everything directly off DC power
Exactly. Millions of RVs and boats let alone off grid houses already do this.
that's the rub. unless you want to use cigarette lighter outlets, there is no standard DC plug.
I'd be afraid to pull down my pants in a room with that monitor on the wall.
I want details, man! What's the standard voltage going to each fixture? What's the voltage coming out of the wall sockets? What design are the wall sockets using? A pre-existing standard? Something else? What about light sockets? Or is all the lighting hard-wired? How much were you able to use from other sectors (like datacenter DC power delivery) and how much was custom made?
Give us something informative! Something worth watching!
Guess I'll just have to read the published article myself.
Have you find the report? I'm still seeking
@@Tamtams94 Nope. They seem to be patenting some of the technology so maybe they're waiting until that's approved? Or maybe they'll never publish it publicly and keep it all proprietary. I hate it too.
Here is Jon's thesis with an abundance of details about the DC Nanogrid House: hammer.purdue.edu/articles/thesis/The_DC_Nanogrid_House_Converting_a_Residential_Building_from_AC_to_DC_Power_to_Improve_Energy_Efficiency/14519604/1
@@PurdueME Very cool. DC powered house was my dream for years. I would remove battery dc-dc and let the battery voltage be the DC microgrid voltage. There is no need to keep it regulated at 390Vdc and all these appliances can run from 300 - 400Vdc voltage range of 96 cell Li-ion battery (3.15 - 4.05v per cell for longevity). Additional research opportunities will be to add dc electric car charging via dc-dc converter, 15 kW diesel generator with 96% efficient 400V permanent magnet alternator with engine exhaust and coolant waste heat recovery for space heating. Use generator to power heat pump to increase thermal useful energy of diesel fuel beyond 39 kWh per gallon. Explore ground source heat pump with radiant floor to increase heating efficiencies during cold winter months. Look into 24vdc LED lighting, it can be interrupted by regular 120vac light switches and efficient 390v - 24v converters placed in the wallplates of each room to reduce resistive losses in the wiring. Also pay attention to RFI emissions from all these switch mode converters to not create interference on HF radio bands to ham radio or shortwave listening neighbors.
Due to voltage drop over distance, I’m thinking output of 48vdc with 24vdc transformers where needed so all outlets are 24vdc. The sockets, I would have the car outlets to plug in a lamp. Along with USB-C outlets at 100W to charge MacBook, phones, tablets. Going to need 48vdc for refrigerator and DC power for gas stove&oven. Outlets like this on the buildshow th-cam.com/video/IBzanvRn2Hc/w-d-xo.html
From Purdue U : "Alongside the nanogrid, household appliances possessing a significant yearly energy consumption are retrofitted to accept DC inputs. These modified appliances are tested in a laboratory setting under baseline conditions, and compared against AC equivalent original equipment manufacturer (OEM) models for power and performance analysis. Finally, the retrofitted devices are then installed in the DC Nanogrid House and operated under normal living conditions for continued evaluation"
"DC house"
*flips AC out switch*
you are living in an AC world, unfortunately, because of the distance current must travel from generation to distribution. 'Current'ly.
More specific info needed, a breakdown of DC appliances & demands + what additional DC appliances could be added like a DC mini split, then give a cost savings asto sizing pv & battery.
Why do you need an inverter if you run all DC appliances and lights at home?
THANK YOU
I believe AC comes into the home - Must be converted to DC. That inv'r also stores what isn't being used. A solar source is already feeding DC into the home, inverter is not needed
AC to DC inverter for when the sun isn't shining. Still pulling AC from the Grid, just using a bigger and more efficient inverter than the individual cheap inefficient inverters that come with most appliances and devices.
@mfb6310 an inverter stores no energy. An inverter can only convert DC to AC.
DC power is a single wave, while AC is a synchronous 60 cycle sine wave, so you need an inverter to generate the sine wave.
Converting AC to DC requires a full bridge rectifier, which is just 4 diodes and is usually a passive device, but they can be active too to filter noise.
@@chriswright9979no such thing as an AC to DC inverter. To convert AC to DC you must use a full bridge rectifier. To convert DC to AC you must convert a single wave to a synchronous 60 cycle sine wave, so an inverter is needed to generate the sine wave.
This video does not actually establish DC being used to power anything. It looks like a regular AC house.
@reiko6105 where's your pfp from, if you don't mind me asking?
Solar power is DC, no?
@@longiusaescius2537it’s Sailor Mercury from the anime Sailor Moon.
Things like refrigerators, microwaves, and vacuum cleaners run off of AC. How did you go about converting them to DC, or is there still some limited AC in the home to run these appliances?
Why use an inverter if the house runs on DC?
I wondered that too but I watched it again, It's a main inverter. The inverter is needed to convert the AC from the "Main" to DC to be stored or used. He wouldn't need the inverter for the solar. This video is really poorly explained and made hastily.
@@LaOwlett
I thought ac-dc was called a converter and dc-ac was called an inverter.
@@kamrankhan-ud5vd I don't remember, which is which. I don't run solar myself, I just have some friends that do.
Too expensive & too complicated = tiny, tiny, market.
This House Runs Entirely By Way Of DC Power. If a "learning" establishment is exclusive and/or expensive, it cannot be considered capable of producing valuable results. That's what TH-cam is for.
Is this more dangerous then old AC systems?
fun fact, a lot of modern electronics have power supplies that will run on ac or dc, since the incoming ac is converted to dc anyway. you can literally just plug them into a 120v battery bank, no modifications necessary.
You cannot have a 120v AC battery bank as batteries are only DC. They can only be DC following the laws of physics.
You are correct though that many things use direct current and have a full bridge rectifier inside to square up a 60 cycle sine wave (AC) to a lower or higher voltage DC single wave. It actually becomes a square wave, technically, because it is considered direct current but still has 60 cycles instead of 0 cycles. The only true DC comes from a battery or from a DC generator.
The big problem with DC is that it's actually very dangerous at higher voltages and will easily kill. 120v AC will give you a shock but 48v DC can kill. 240v AC might knock you down but 300v DC will instantly stop your heart. AC is much safer at high voltages while DC is even safer if it is 24v or less.
The physical problem with DC is that it must be a low voltage but the trade off is high amperage and so you have great transmission losses. AC can travel pretty far without losing too much voltage, but DC loses power in short distances, 10 feet is about the maximum you can go without significant losses at a low voltage
Them: every home that uses ac to dc conversion is wasteful.
Also them: so we have a GIANT inverter from AC to DC transformer! 🤔
My thoughts before I search if someone is making use of this idea. There is loss of power during conversion process. Second person I heard it from. It's time to rewire my entire house.
How is this different from any solar home... there's an inverter... now if you used 100% DC without an inverter that would be something.
I'm saying this for years and even Nickola Tesla pointed this out back in the day. Dc is the future and indeed most appliances use DC. Problem is is that many appliances use different power ratings after their built-in converter (transformer). So inorder to convert the whole industry a new standard needs to be created and houses need to be adapted to that new standard.
Probably DC and AC would be standard together in a house. But with different mindset of how to deploy DC then we currently are doing.
@Demetrios Christopher The lastest version of the USB-C standard supports up to 240W (5-48V) with the right cable, so I this will problably be the future of connecting DC appliances in homes. 240W is not enough for everything, but for a lot it is enough and they will most likely increase it in the future again so if one just buy or make high quality cables then it would be future proof when they update.
I think that was Thomas Edison who advocated for DC and Tesla who advocated for two-phase AC.
Exactly
KInd of left us hanging there.
Small, DC power grids for individual homes are used all over the world in Third World countries.
People who cannot afford power inverters we’re just a purchase of a power inverter might be six months of their entire gross wage for the year. It is just out of their reach for a whole small villages..
They’re DC refrigerators, microwaves, televisions, radios washer, machines dishwashers all the motors runoff low-voltage 12 V 24 V or 48 V . Directly off solar panels and batteries..
Very little expensive Electronics, because they simply cannot afford it .
Americans Europeans developed countries have a very sophisticated very expensive and energy wasteful inefficient power management systems .
Every time you have to step voltage up or down, you lose power in inefficiencies
where's the payback and savings?
This is laughable. They have the AC converter because they're too lazy to convert each appliance to run on DC. Purdue engineering is weak.
LOL i know its kinda funny but the even funnier fact is they don't even have to convert them as ll the appliances we have and use they already have an all DC version of them.
Per PurdueU: "Alongside the nanogrid, household appliances possessing a significant yearly energy consumption are retrofitted to accept DC inputs. These modified appliances are tested in a laboratory setting under baseline conditions, and compared against AC equivalent original equipment manufacturer (OEM) models for power and performance analysis. Finally, the retrofitted devices are then installed in the DC Nanogrid House and operated under normal living conditions for continued evaluation"
i would use them tbh, most if not everything these days is already converted to DC via switch mode power supply's anyways.@@connicrow9463
They likely didn't have to do much in the way of conversion. Many appliances already use DC and just have a rectifier of some type inside already. The biggest issue would be getting the correct DC voltage for individual appliances.
All of the upper crust, silver spoon students are mentally lazy. That's why they buy a degree.
Have you published a report or student thesis or something?
Here is Jon's thesis with an abundance of details about the DC Nanogrid House: hammer.purdue.edu/articles/thesis/The_DC_Nanogrid_House_Converting_a_Residential_Building_from_AC_to_DC_Power_to_Improve_Energy_Efficiency/14519604/1
We are told it's cheaper, and I'm sure it is: but that's after investing massively in solar panels, and inverter and a thumping big battery. It would be help to understand that overall financial cost/benefit of this approach over 1 year, 5 years, 10 years before it can be seen if it really is cheaper.
Okay I have to ask the question, is it more or less lethal to a toddler with a fork in the socket?
@@Shadowwand All things being equal, DC is less lethal. 120VAC has a peak voltage of 170 Volts. The 120VAC is the "average" of the sine wave voltage over its frequency so 120 VAC peaks at 170 Volts and it is equal to 120 VDC.
A.C. is said to be four to five times more dangerous than D.C. For one thing, A.C. causes more severe muscular contractions. For another, it stimulates sweating, which lowers the skin resistance. The 60 Hz frequency of AC is rather close to your heart rate which causes Arrhythmias in your heart.
DC is not without issues. DC sparks don't self extinguish like AC does so this would be a fire hazard problem.
If we are going to go to DC, we would need to redesign all electrical outlets. I suggest looking into the British plug. The Brits have done a superb job with their outlet and plug design. Tom Scott has a TH-cam video on British plugs.
We need more of this
I’ve been thinking of doing this for years. I have a spreadsheet full of data, how to run on DC. Just saving up funds to do the conversion. Totally makes sense, glad someone else is also thinking this.
Since when was DC conversion only 10% efficient?
Also they bought too many PV panels
That’s totally awesome!!
"this house runs on dc power" 15 seconds later "this is the house main inverter" shows a gigantic inverter, where's the dc xD i didn't think university would make such bad videos
While interesting, I wonder how they have overcome (or if they have) the difficulty of getting the voltages that the various devices want.
What AC has over DC is transportability. One can generate it, step it up way high in voltage to minimize losses on high-tension lines (lower current). Then step it back down to feed homes/businesses.
Once the AC gets to the appliance, it can then step it up/down as needed...one does all of that as AC before the final conversion to DC (if the device needs DC). Between transformers that efficient step voltage up/down and power factor correction, getting AC to the voltage one needs isn't all that inefficient.
One has 380VDC as the supply, in the example video...computers often need an amble supply of 5VDC as their highest current demand...how are you getting it down to 5VDC efficiently? Most other common household appliances run on DC voltages lower than 380 (and I suppose 380 was partially chosen because going higher in voltage is more difficult for DC without some form of AC component in there, like a switch mode power supply...which takes advantage of AC's properties). I'm sure another reason for keeping the DC voltage high is to reduce the current on the wires feeding devices to keep them needing to be extra large to avoid heating up.
It's interesting, for sure. It had a degree of sense when one is trying to use DC power generation/storage (Wind and Solar) but for an overall practical concept, I guess we'll see.
The same way that 12v dc automobile systems convert the 12-14v from the battery and or alternator to charge cell phones that require 5v or run computers/data terminals that require 19v? I believe it's called a buck or boost converter.
Sure...but to do that you are going through an AC/DC conversion...but if the claim is that starting with DC prevents the wasteful conversion...you lose that argument if every time you need a different voltage, you have to do double conversions.
Transformers are relatively efficient and most AC devices use SMPS...which are also relatively efficient. So, if you are just going to run the DC through another SMPS, where are the big savings.
In a car, one normally will just regulate down the higher DC to the lower DC...which will burn up the excess power as heat...something one would want to avoid in a whole home DC system. For the most part, everything designed for a car also is designed to operate a car's nominal voltage too. Something not enjoyed in homes, at this point.
Most switching DC/DC converters are 98% efficient. Biggest losses in AC conversion happen in the step down transformer stage of the circuit. Magnetic hysteresis just burns power in the transformers.
DC is the future
Way to go JPO!!!!
this is not dc lmao
This is good because we are experiencing energy crisis