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According to HN you can totally do this and I'm just wrong.
Most solar installs work by tying into the existing main breaker of the home.
The cheapest way to do this is to leave the line feeding from the power meter to the main panel untouched. Instead you do anti-islanding detection at the inverters, and when they detect that mains is "down" they automatically cut off to prevent trying to backfeed power to your whole neighborhood during an outage (dangerous, not a good idea).
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Second issue - there are many appliances that are NOT happy about being turned on and off at random times, and it can significantly impact their lifespan (ex - refrigerators, acs, computers, washers & dryers, etc).
So given the variability of direct solar, you don't want to accidentally destroy your ac unit by having it turn on and off 100 times as random clouds float by.
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But! If you're willing to install even moderate battery capacity (and LFP is getting quite cheap as well). Then you can absolutely do this. It's just more complicated and more expensive.
You need to wire in a mains relay (~$1,000 depending on the unit) and install some battery capacity to prevent very frequent startup/shutdown, then go through some painful additional signage and labeling requirements (at least in most of the US) and also install some additional shut-down switches on the exterior of the home (ex - to automatically turn the inverters off, and to shutdown the battery system).
Then, yes, you can absolutely stay on solar power while the grid is down. In the same way that people are allowed to run whole-home generators to stay online when the grid is down.
Pretty much. I vaguely remember a couple of "off-grid" devices that try to automate this for you (ex - you can set a priority on each breaker, and as supply dips, they get dropped in order of priority).
But functionally speaking, you just need to install a battery. Frankly - Batteries aren't discussed as much as solar, but the big breaking point we're hitting right now isn't just that solar has gotten incredibly, unimaginably cheap.
It's that BOTH batteries AND solar are getting very, very cheap. And the new generation of batteries are also considerably safer than the original lithium batteries.
Lithium Iron Phosphate batteries (LFP) are ~$60/kWh right now. I can buy them commercially in bulk in the US around ~$80 (pretty much all china production - full stop. Historically, I've bought EVE cells, but I'm now seeing direct BYD branded cells as well).
If sodium-ion can hit the same price points (and odds are looking better and better they'll both hit and then plow past as they bulk up production) then my read is that modern power plants are going to be very, very different.
They'll look a lot more like the connection structures we see for trees - a bunch of connected independent installs that can optionally cooperate as needed. Ex https://www.bbc.com/future/article/20260928-a-virtual-power-...
Home circuitry, load center need to be redesigned for V2X (vehicle to grid, home, load, etc), plug-in solar and batteries, solar/batteries replacing generators, etc. You seem to have thoughtful ideas about these and it would help to have someone knowledgable articulate how it should be done.
[1]The idea is that they can change the world right now by understanding what they want in their world (clean and free energy) and that they need to ask for those changes because buildings last ~100 years. The lowest hanging fruit is future-proof all construction and have it be ready for incremental changes without needing any labor or permitting work.
Imagine I was running a non-profit that teaches middle and high school kids about the human body and the first thing I have them do is to look up their legislator and ask them to pass anti-abortion legislation.
In both situations, kids are being used to promote a political agenda.
It's no different than the parents who bring their kids to protests and make signs for them to hold. Except parents likely explain why they're bringing their kid to a protest. This guy just straight up uses them for his own political goals before even explaining why they're doing it.
You should find that icky.
You are just making up ridiculous things that I never said. I said nothing about protests. Its your thing. The kind of teaching you'd encourage is teach the kids vaccines cause autism. Bring autistic kid to protests. Perfectly scientific.
You appear unable to grasp this because you don’t think building code is political. It is, however, because it is literally law.
Attempts to persuade those wielding power to set the law, in this case building code, is the definition of political activism.
I don’t know why you are bringing autistic kids into this discussion.
Its kids deciding for themselves about the world they want to live in and what features they want in it. Buildings last ~100 years and most likely they are going to live in a home that was built in the past. If they want modern features or amenities without spending a fortune rebuilding the house, its best to future proof.
> the first thing I have them do is find out the county building code engineers[1] and ask them to update the code
Based on your other comments, it doesn't appear you're qualified to be teaching kids about this stuff in the first place, given the lack of understanding about basic electrical code.
The real world is full of tradeoffs. If you also told the kids that mandating 240V outlets in garages would increase the cost of new homes by $1,000 they may have a different opinion on the matter, given that those college kids you're teaching probably imagine themselves trying to buy a home in a few years.
Years ago I owned a home built in the 1980's that had a central vacuum system. It was a cool concept but utterly useless. No new homes that I know of have these systems anymore.
Imagine you were born in the 1960's and thought that these things were the future. Think of all the vacuum bags we'll save from the landfill with this technology! Think of all the money people will save on vacuum cleaners!
> If they want modern features or amenities without spending a fortune rebuilding the house, its best to future proof.
The future is uncertain. Ten years from now people may not even want to own cars if autonomous taxis take off. The whole concept of a garage may morph into something unrecognizable to us today. But if you get your way, we'll waste tons of money putting 240V outlets that never get used as intended.
What is the environmental cost of mining and producing literal tons of copper wire and installing it in new homes for outlets that never get used? What is the cost of using skilled electrician labor to install useless outlets instead of having those same electricians working on building a new solar plant?
I encourage you to discuss these tradeoffs. Don't just ride the good vibes of teaching kids how to use political activism to "make the world a better place", without ever actually teaching them how to evaluate if a certain choice actually makes the world a better place.
If people want a 240V outlet in their garage, they are welcome to pay for it. It doesn't need to be mandated. Home builders aren't stupid: they know what their customers want. If they think they can sell that amenity, they'll install it. If they suspect their customers won't use it, they'll omit it and offer them a lower price. That is the most environmentally optimum solution in the first place. Only those homes that intend to use these outlets should get them.
A home has ~300 outlets. If each outlet costs $1,000, it would cost 300K just on outlets for the builder. The cost of an outlets is in cents or fractions of cents, these are manufactured in bulk and shipped from China, not artisanal hand-crafted NFT outlets from etsy as collectible items for speculation.
Homes ALREADY have multiple 240V, for HVAC, electric stove, dryer. Dryer is in the garage or in a laundry room right next to the garage. An electrician does all the wiring and outlets, which costs nothing at build time. However, if you have to add it later, it will cost $3,000 - $,5000 to retrofit.
> What is the environmental cost of mining and producing literal tons of copper wire and installing it in new homes for outlets that never get used? What is the cost of using skilled electrician labor to install useless outlets instead of having those same electricians working on building a new solar plant?
Most of the outlets (70 - 90%) in the house are unused. There are 10+ outlets just in the master bath and closet. If you are so concerned about utilization, why not start a campaign to cut the total number of outlets to a total of 10 per house? You would have saved $290K/house going by your math and hailed as the savior of american dream, making homes affordable for everyone.
> Years ago I owned a home built in the 1980's that had a central vacuum system. It was a cool concept but utterly useless. No new homes that I know of have these systems anymore. And you could have also bought a home with a stable. Means nothing. You could have also bought a home without plumbing or indoor toilets.
> The future is uncertain. Ten years from now people may not even want to own cars if autonomous taxis take off. The whole concept of a garage may morph into something unrecognizable to us today. But if you get your way, we'll waste tons of money putting 240V outlets that never get used as intended.
Or there could be a manhattan project to build coal based cars and all homes need coal storage. Everyone could have converted to Amish and no need for any modern technology. Or people may stop using bathrooms and go back to nature, so we can remove them as well. Or Elon Musk would've shipped everyone to Mars, Earth is destroyed, our work here is finished, I promise we'll build something better on Mars, Lets go. Or there could be genocide or people sent to concentration camps. The future is unknowable to most people who can't think where the world is headed. ICE cars are over everywhere, the world is at 50% EVs now. The only exception is US.
> Home builders aren't stupid: they know what their customers want. Lots of builders are already building with it. Some states have mandated it. It is not uniform. Just think about bathrooms being introduced and not everyone knows about it. But if you make a building code, builders will build to code and no more defecating outside. Information about good ideas does not spread immediately and all at once. After the invention of bathrooms and indoor plumbing, it took 100+ years for all countries to expect it.
A 240V 50A outlet requires a 6 AWG wire with four conductors. The wire is $10 per foot. The outlet is $50, the box is $30. The breaker for the panel is $100. Just material costs get you to $500. Throw in installation labor and you are easily north of $1,000.
If you think the two outlet types are even remotely similar in cost you really don’t have any business teaching this stuff.
And no, just because you have a 240V outlet in the laundry room doesn’t mean you can piggy back off of it for another outlet in the garage. You’d need a breaker rated for 100A and wire rated to deliver that kind of current, which I suspect would be even more costly than having two separate wire runs and circuits.
My frustration is that you have very little knowledge of how any of this works, but are recruiting equally ignorant children to engage in political activism to change building code in a way that will increase the cost to build new homes and cause more damage to the environment through wasted copper usage. All under the guise of educating them, ironically.
As they say, the road to hell is paved with good intentions.
Do you honestly think the reason some new homes a century ago were built without modern plumbing after it was invented was because people were unaware that such a concept existed? You think it was an information problem?
No, it was because of cost. Most people were fine using an outhouse or chamber pot and had done so all their lives. Sure, indoor plumbing would be awesome but the cost to install it wasn’t worth it to the buyers of new homes at the time. Which is exactly why people choose to omit a 240V outlet from a newly built home today.
Think of how many fewer homes would have been built back then if you mandated each one contain at least one toilet. You can’t just conjure things into being by enacting rules and regulations that say something must be so. In the real world things cost money and require resources to produce.
I strongly encourage you to watch some videos of electricians installing 240V outlets on YouTube and educate yourself on why they are expensive. Then go watch some economics 101 videos on the law of supply and demand, and what happens to supply when you artificially increase the price of a good through government mandate.
There’s nothing wrong with being ignorant. But choosing to stay there, that is an unforgivable choice. If you’re going to teach this stuff, get the knowledge you need to do it well and cut the political activism.
The kids will likely respond better and I think you’ll have more fun too. Understanding how electricity actually works in a house is way more fun than reading building code anyway.
It's bog standard cheapest possible in Australia because it is standard in Australia - kettles there boil faster while drawing more amps.
If you follow that thought through ... 240 V will be cheaper in the USofA once wiring for EVs, home solar, smart grids, etc becomes more common.
> There’s nothing wrong with being ignorant. But choosing to stay there, that is an unforgivable choice
Something for all of us to reflect on.
US laundry rooms and kitchens have had standardized 240V outlets for decades. They’re just sized to deliver 40A+, and that means big breakers, thick wire, and big outlets and outlet boxes.
Installing a 240V outlet that can deliver 50A anywhere on planet earth is expensive because it takes expensive materials and labor to accomplish.
Copper costs what it costs in the US, Australia or Africa. Skilled labor that builds to code is expensive in those places, too.
This is not a standardization problem. It’s a physics problem, which dictates the cost of the system and cannot be affected by government regulation.
However I am aware that most appliances that would use 30 - 40 amps are required to be wired in and not by way of an outlet. That's not to say that always the case, and since so much of the rural areas in my parts are single phase there's been times working around a rough country shed -- it'd be more than one outlet plus 15 plug that's melted because someone was pushing their luck with a hot welder.
I used to have an extensive book on the code two or three decades ago ... but code changes - possibly for when common sense ... doesn't. Below [1] might offer a guide as to how it's supposed to happen down under.
[1] https://cccengineering.com.au/design-memos/as-3000-explained...
A standard Australian outlet is officially 230V 50Hz at 10A. (It used to be officially 240V, but the standard was changed to 230V to harmonise with the EU standard; but given both figures come with error bars, this didn't necessarily make a difference to the actual voltage coming out of the wall.)
The US standardly uses split phase, in which a single phase of a three phase supply is split into two phases 180 degrees to each other, each of which is 120V to neutral, but 240V across each other; so the heavy duty US sockets use both of the split phases. (Originally it was 110V/220V, but was gradually increased up to 120V/240V over the 20th century.)
By contrast, in Australia, split phase generally isn't used except in rural SWER (Single Wire Earth Return) installs. Houses usually either get 230V single phase, or 400V three phase (sometimes still called 415V, which is what it was under the old 240V standard). A standard 230V socket is 10A, but there are also variations designed for 15A and 20A (plus more rarely 25A and 32A) – the higher amp plugs have slightly different pins designed so you can't plug a higher amp appliance into a lower amp socket.
While most Australian houses only get single phase, a decent minority get three phase to supply larger air conditioners, or for EV charger or solar-battery installs. You also sometimes get houses wired with two out of three phases, which is different from the US / rural Australian split phase, in that you are getting two phases with a 120 degree angle between them, not two phases with a 180 degree phase angle.
Where Americans would use 240V at 50A, Australians would either use 15A or 20A single phase outlets, or if that's insufficient, 3 phase (25A and 32A single phase outlets, while standardised, are rare in residential settings). In the US, a residential street is commonly only wired with single phase, with utility pole transformers to split the single phase into two split phases; Australian streets are usually wired with three phases, so upgrading a house to a three phase connection is just running more wires.
Where I live, on sunny days, the grid goes over 253V (230V nominal +10%), so in order for me to generate anything, my inverter disconnects itself from the grid.
[0] It is becoming way more common now, though.