Hacker News Reader

(Heat pump) Hot water heaters and washing machines are not major power draws. Some rough figures on power consumption of typical appliances, from most to least:

  Continuous-flow electric water heater: 20 kW
  Heat pump or central air, big home: 12-15 kW
  EV charger: 7 kW
  Electric tanked water heater or hybrid water heater in electric mode: 7.2 kW
  Clothes dryer with heating element on: 5 kW
  Heat pump or central air, small home: 3-4 kW
  Electric oven: 3-5 kW
  Induction range: 1.8 kW
  Instapot: ~1.5 kW
  Toaster oven: 1-1.5 kW
  Electric kettle: 1 kW
  Microwave: 1.2 kW
  Dishwasher: ~500-1000 W
  Heat pump water heater: ~600W
  Washing machine: 500 W
  Vacuum cleaner: 200-300 W
  Home server or desktop: 100-200 W
  Box fan or air purifier: 100 W
  Laptop on fast charge: 65W
  Laptop on slow charge: 30W
  LED light bulb: 12-15W
  Cell phone charger: 6W

For reference, 200A electrical service can supply up to 24 kW of power, and even 120A service in older houses is good for about 14.4 kW.

Individually coordinating appliance loads or including a battery with each appliance seems like an inefficient, expensive and unnecessary extra step. Basically, all you need to do is a.) charge your EVs at night when nothing else is running b.) don't use electric water heaters unless they're heat pumps and c.) insulate your home if you're using heat pump HVAC. All of which you should be doing anyway. The kitchen appliances are easily manageable if the EV and HVAC are not running at the same time, and everything else is rounding error.

There might be some benefit to grid-coordinating EV charging and heat pump HVAC operation, particularly since these are the cases where naive loads all hit the grid at the same time, and they already come with batteries included (literal ones for EVs, thermal batteries for HVAC). For smaller appliances it's totally unnecessary though.

I don’t think it’s impractical to upgrade service lines. It is, however, impractical to get PG&E to approve the upgrade. (For us, that process cost about 3 years and $10K. They ran a wire 6 feet from an existing transformer to a pole we had to install ourselves).

When they pass these laws, they should come with an SLA for the utility provider to approve “engineering” plans for the utility hookup and whatever transformer upgrades are required utility-side.

There should be a ~ $250 per day fine, payable in cash to the homeowner once the SLA is exceeded. That’s roughly 2x normal homeowner costs due to delay of construction approvals (and therefore financing / alternative housing costs for those days) and using gas generators to power the site.

> (For us, that process cost about 3 years and $10K. They ran a wire 6 feet from an existing transformer to a pole we had to install ourselves).

Must have been a while ago because in 2021 they charged me $0 (not a typo) to go from 100A to 200A. It took just a month or so to arrange.

It's really amazing how people can talk about 200 amps as if it's nothing. We have a household installation of 40 amps (220) and last year there were months that cost 400 euros per month on electricity, and we are not heavy electricity users (we have no electric cloth dryer but have a small robot mower tho)

It is almost like talking about 400HP cars/suvs, my 3 cylinder car is doing just fine at 84 kW max.

Am I being pedantic?

You're talking in Euros... we have 230V power, while Americans and a few other holdouts still use 110V. The problem is, the lower the voltage the more current you need - an 1 kW vacuum draws 9 amps in the US, but 4.5 in Europe.

The unit of billing - kW/h - however remains the same.

This sounds plausible but is subtly incorrect: the US uses split phase power and 100A means 100A on each of the two legs (+/-120V). So if you balance the legs correctly, you can get 240V*100A on 100A service. This is important for example for car charging where both legs are used and balanced.

America is 120v now, I believe - and many houses have a centre-tapped neutral supply [1] which means they actually can have 240v outlets in garages, workshops, utility rooms (etc) for high power devices.

[1] https://electronics.stackexchange.com/questions/487836/how-d...

So this is different from a 3 phase system (N L1 L2 L3) with 120 degrees shift between the lines? It is instead basically a 2 phase system N L1 L2 with a 180 degree phase shift between L1 and L2?

I was already confused with the 240 being mentioned somewhere in this thread... it becomes a bit clearer now.

Not an electrician, but yes (I think).

https://en.wikipedia.org/wiki/Split-phase_electric_power

Most US residential housing is fed off a 240V center tapped transformer. Center tap is connected to ground and neutral at the breaker panel. That gives you two 120V phases to neutral. And 240V from phase to phase.

In the breaker panels the phase alternates as you go down the rows of breakers. So you can install a dual breaker for 240V. Typically only large appliances like stoves, water heater, driers, and air conditioners are 240V. Everything else is 120V.

I heartily recommend a three phase induction stove. 400V of cooking power (mine is rated at something like 8kW…?). Carbon steel pans get ready in seconds.

American houses mostly have air conditioning, which is a huge load. We don't, and make better use of shades, awnings etc.

European houses have had two or three decades of efficiency improvements made to everything, so we don't have the 5kW clothes dryers mentioned above.

Maybe this is a bit of a tangent but... shouldn't the world as a whole not be thinking about how to consume less in stead of obsessing with how to do the clean energy transition, without changing our habits a bit?

If you think about it, there is still plenty of room for optimizing our energy consumption.

The trend seems to be, replace the gasoline car not with a more fuel efficient one but rather with a car weighing almost double because it has to drag along a huge battery. Then replace all copper wires with double the section (copper mining, plastic production, tearing open perfect roads, ...)

Some ideas, not very far fetched I would say, combine a few of these will get us a long way:

Car pooling.

Electric bicycles.

Insulate your house better?

Taking turns with neighbours to do grocery shopping or bringing kids to school.

Try to repair stuff in stead of bying new.

Drying clothes with renewable wind energy. (a hanging rack)

> Car pooling.

> Electric bicycles

> Insulate your house better?

> Taking turns with neighbours to do grocery shopping or bringing kids to school.

> Try to repair stuff in stead of bying new.

> Drying clothes with renewable wind energy. (a hanging rack)

People do these things anyways with the right incentives, just to save time and money.

But we still need to get off of fossil fuels for transportation and electricity generation if we want to avoid the worst climate change scenarios.

The reality is that people really value convenience, and we have to find sustainable ways of delivering that. That might mean a great electric bus system, EVs, community thrift exchanges, etc

I agree, but it needs to be a combination of change of infrastructure and people's habits. After all it is just culture and culture evolves,so let it evolve in the right direction. 200 amps to every household seems not to be the right direction.

As behind-the-meter demand management technology advances, and behind the meter storage becomes more affordable, we will be able to increasingly support high power use cases without needing 200A service drops at all. This is where we will end up: sipping power through a straw and storing it for short bursts of high-power usage.

> Car pooling. I work from home and hate riding/coordinating with others so I’ll alway just go on my own.

> Electric bicycles

I only ride bicycles for exercise or as an activity but never to go somewhere. I’m no longer 12.

> Insulate your house better?

If the government wants to use my tax dollars for this instead of SNAP/TANF then I’m all for them paying for it but it’s not going to be me paying.

> Taking turns with neighbours to do grocery shopping or bringing kids to school.

See point #1

> Try to repair stuff in stead of bying new.

I do this where possible because I’m cheap but I doubt it is any kind of significant savings of energy.

> Drying clothes with renewable wind energy. (a hanging rack)

Now I’ve got clean clothes covered in dust and pollen. Thanks.

I understand your points. I'm sure those are valid for you. I'm thinking more about the whole picture. You say you work from home, that's already big influence.

My point in this discussion thread is, i saw 200 Amps at 240 V per household being mentioned, i want to show this should not be the norm or trend. Imo this way of thinking is not leading to an efficient system.

If you have an electric car, you probably don't need to charge it most of the times at the highest current. And when you do, you won't turn on all electric devices with high amperage.

The other examples are just examples, not everyone needs to apply them all. I advocate for the culture shift, the more-is-not-better mentality. This needs to go hand in hand with cleaner technologies and government policies.

It depends a lot on your existing service. For many homes the wire is already rated for 200A, and you just need a new main panel. In those cases the utility charges you $0. On the other end of the spectrum, some homes have buried power lines where they need to dig up the street and driveway to run a new higher-rated cable to your home, and I've heard of those costing upwards of $50K.

In my case I needed a new wire drop, but it's still didn't cost me anything. The panel upgrade was very pricey though.

It's different depending on the line that runs to your home and the transformer serving your street. If the line to your home has enough diameter to carry 200A and the transformer and the main line have enough spare capacity, all it needs is to exchange the main fuses/circuit breakers on the utility side. Most new constructions these days are severely overbuilt to accomodate the rise in electric car chargers.

For older constructions however, it can be more involved - the line from the main line to your home might need an upgrade, the main line might need an upgrade or in the worst case the transformer might need an upgrade. The further up in the grid you go, the more expensive it gets for the utility - and some measures might even require significant work involving construction permits.

In our situation, the issue was that the service had been disconnected, and we needed to move the meter about 20 feet (no obstructions, no buried lines).

> If that's your contingency plan, check that a safety valve doesn't close when power is lost.

And for good reason. Gas cookers require ventilation, to prevent carbon monoxide build up. An electric extractor fan won't work during a power cut.

Well you could open a window.

In the middle of the night while you are asleep?

Why is your stove on while you sleep?

It's probably connected to the internet, downloading critical updates to the burner software and ads to display while you're cooking.

Sure, but my point is to remember to do that. Extractor fans are for more than extracting the smell of onions or fish.

It's very bold of you to assume that my kitchen has ventilation at all. There's an electric extractor fan that just blows the air back in your face. I've seen other people's place where they don't even have that charade.

I'd love to have a real setup. Unfortunately I've not been given that option and it is the same for many others.

I don't know how the codes are where you live, but in EU the norms are for natural ventilation in kitchens where gas stoves are used.

> … getting a feed to your house that can handle your hot water heater, stove, washing machine, and electric car charging all at once.

This wasn’t on my radar as being a thing. What type of service is typical out there? Where I am, 200A is fairly normal and I haven’t really perceived of the concept of not having enough electricity to run a family as a thing.

Do people trip the main breaker more than “almost never” out there?

No matches?

Worst case at 240v :

Electric hot water heater = 20 amps

Electric stove = 50 amps all burners on and oven

Washing machine = 15 amps

Car charger = 50 amps

Total = 135 amps

Standard residential service in the US = 200 amps split phase @ 240v

Whats the problem?

All the other 15 amp circuits people take for granted for things like lights, the clothes dryer and the heat/cooling system you left off your list (heat pump + air handler + emergency heat coils)...

Add in the 80% rule and 200amps doesn't go as far as one might hope in a gas free-house.

There are some induction stove startups that are using batteries to not only not require 240v hookups but perform even better than a standard induction stove... the idea is that with cheap battery technology you can take advantage of the fact that not everything in your house will be running and charging at the same time.

I run my washer and dryer on a single 15 amp circuit. Heat pump dryers are very efficient.

The 80% rule is for running circuits and for breakers. It has nothing to do with actual load capacity. I.e. with 200A service you can have well beyond 200A nominal worth of breakers in your box (250A), but when all those things are running it should still use 200A or less if the 80% rule was followed.

I did not make the list, I was replying to the list given.

None of those devices pull the rated amount continuous except may the car charger which can be adjusted for less draw / longer charge time if needed.

Simply scheduling car charing for overnight would eliminate any issue, even so there is plenty of headroom on a typical residential system.

There are a lot of jurisdictions where piped natural gas is not available and 200 amp service is very common, as a practical matter it is not a big deal.

Requiring new builds to have even more electrical capacity and more robust incoming infrastructure is a win-win-win situation and hopefully that is what code & consumers demand.

For a new build - the building code should suggest/require that a battery backup/Powerwall circuit be added that only supplies the essentials.

If you can stick to plugin hybrids and go without AC during a power outage...

Electric hot water heater = 20 amps

Electric stove = 50 amps all burners on and oven

Internet, Misc = 1 amps

Total < 75 amps

You didn't include air conditioning, vacuum, power washer, power tools, etc. It's not that you'd be running all these things at once (although AC run a lot), but it's pretty crazy that you could even come close to tripping your main breaker.

Pretty crazy? Not sure I follow, if you push anything fancy to the limits shit will happen, and over the limits there are some guarantees you will not like the result.

Its not like its year 10'000 and we polished technology, infrastructure and everything to the max physics allow. For example you can easily break whole internet if significant portion of its users decide to download something relatively big at the same time.

The post I was replying to did not specify those devices.