This doesn't make sense - NYT article about a solar installation in the US

[ckambiselis]

Here's an article from the NYT that makes me wonder if the correct writer was chosen to write it. (The link is a bit long because I used the button that gives you access to the full story with having to pay)
 Old Power Gear Is Slowing Use of Clean Energy and Electric Cars https://www.nytimes.com/2021/10/28/business/energy-environment/electric-grid-overload-solar-ev.html?unlocked_article_code=AAAAAAAAAAAAAAAACEIPuonUktbfqohlSFUZCybfQMMmqBCdnr_CxrEmiW67IS6LSCxFyeEYBZTH9kPAbrZ5ZtB20C6aSJpGLrI1QPt7wqpEOEhkUUylvN2EhJEBaW0TmL6EY1kXjdjLTKxqtnjjdHW4I-Nyg-fh5RzZa2DhRKXZ2XM-IF1goo82dQqoxXJekquWQOR339J1j-wzRcwvHUd2byGItvTjDh9-PczXLU2Pr1lrBJwKHG3bjtWe6LofcAxNClKgTX534Ww06t00K8pAde-kbEZmIJyi9O1XXm94L46pB4kyR5zXlNhotL3Oqx-Nwamm1gOP1yYDNTuTwh7SXho8g_I

[Ed.Kloonk]

Whilst I heard about this story elsewhere, the article don't tell us more than what we already know. I'm wondering if it was simply a non-story and the paper has sexed it up with keywords to attract google juice and eyeballs.

[richard.cs]

This is a well understood problem isn't it? The electricity network impedance is on the high side, and the transformers are set near the max voltage so that the minimum voltage can be maintained at the end of the line without generation. Then when you have generation and the voltage slopes the other way the inverters trip on overvoltage. Sometimes you can put the transformers on a lower tap, sometimes you have to add more copper to get the impedance down.

How much it costs to fix depends exactly which part of the network needs adjusting. It's probably worse in the US style system of many small transformers. Do those even have selectable taps or does it have to be fixed at MV?

[bdunham7]

How much it costs to fix depends exactly which part of the network needs adjusting. It's probably worse in the US style system of many small transformers. Do those even have selectable taps or does it have to be fixed at MV?

No, they typically don't have and don't need taps.  Actually the small local transformers work very well where they are used, which is in the vast majority of rural and suburban areas in the US.  Problems such as are reported here are the result of very advanced decrepitude in the main distribution system, along with poor understanding and planning when installing the systems that they are talking about.  The people with the solar system that they can't hook up should have thought about batteries and the guy whose Tesla melted his panel (or whatever) should sue his electrician. 

[Siwastaja]

There are two solutions;

Fix the grid,

Or accept broken grid and add local energy storage, creating your own island of better "grid". The original grid then becomes just one unreliable source of energy that can be consumed when it's available and needed. Also push back some charge into that grid when that is possible, at power level which works.

Living with crappy infrastructure sucks but really, what can you do. Complain to politicians; or build a proper system for you; possibly shared with neighbors if they are sensible people.

I'm lucky to have decent grid available but if it wasn't so, I would see no other option than to build by own island consisting of solar, possibly wind, battery storage, thermal storage and diesel generator (with waste heat recovery). Then if there was some joke of a grid, I could consider adding it to my mix, depending on the monthly/yearly fee.

[richard.cs]

No, they typically don't have and don't need taps.  Actually the small local transformers work very well where they are used, which is in the vast majority of rural and suburban areas in the US.

Out of interest, do you have any idea what the typical source impedance measured at their LV terminals is? The large transformers in European-style distribution are about 10 mOhm so impedance seen by the consumer is utterly dominated by the cabling and usually 100-300 mOhm

[bdunham7]

Out of interest, do you have any idea what the typical source impedance measured at their LV terminals is? The large transformers in European-style distribution are about 10 mOhm so impedance seen by the consumer is utterly dominated by the cabling and usually 100-300 mOhm

They typically rate them with a 'Z factor', which is the percentage of the OC voltage required to circulate full rated current into a short circuit.  So if you had a very typical 50kVA transformer at 250V and a Z of 2% (which I think is actually stated as 0.98 for some reason) then that implies that it takes 5V to circulate 200A, so that equates to 25mR.  It also results in a maximum fault current of 10kA, which is the maximum for typical residential panels and breakers.  In my case, the relatively short (30 ft) of wire between that and my panel is probably about the same 20 to 30mR.

This type of transformer is what you would find in my neighborhood feeding 4 houses, each with a 200A service panel.  They are very conservatively rated, something like 175% continuous and 400% for one hour at 23C.

[rstofer]

Transformer impedance is measured, not in Ohms, but in percent.  The percent impedance is the percent of primary voltage required to create full load output current into a short circuit.  A standard oil filled transformer might have 6% impedance.

In the end, this means that 6% impedance can deliver (1/.06) or 16 times nominal full load current into a short circuit.

Take a 240V  75 kVA  single phase transformer which should have a nominal secondary current of (75000/240) or 312.5 Amps.  Now multiply this by the 16 value and get a maximum fault current of 5000 Amps.  This i a convenient result because most residential circuit breakers have a 5,000 AIC (Amp Interrupting Capacity).

This 'back of envelope' calculation assumes an infinite fault capability on the primary which is not true but it's good enough for the AIC calculation.

That's why several houses will often share a single 75 kVA transformer in a neighborhood.

I didn't read the article but I used to have a 8 kW solar array and never had a problem.  My net utility bill, settled up once per year, was just the meter charge of $5/month.  I still used utility power at night but I sold back a lot of power during the day.  In my area, it doesn't pay to over-generate because the customer is precluded from becoming a net generator.

The charger for my Chevy Bolt takes about the same amount of power as my microwave.  Think about Thanksgiving and all the concurrent ovens, stoves and microwaves.  I don't think EVs are going to be a problem.  The fast chargers may be an issue, I don't have one,

[thm_w]

The charger for my Chevy Bolt takes about the same amount of power as my microwave.  Think about Thanksgiving and all the concurrent ovens, stoves and microwaves.  I don't think EVs are going to be a problem.  The fast chargers may be an issue, I don't have one,

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

[james_s]

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

I don't think it will be a problem. I have a hot tub that draws 11kW if both pumps and the heat are on full power. My clothes dryer is 5.5kW, I used to have an electric stove in the kitchen that I think was around 10kW fully utilized but that's gas now. The only EV I have direct experience living with for a while was a Tesla and in that you could set the charge current to anything you want up to the max, so if it's on a shared circuit or grid capacity is limited you can back it off. It's only a matter of software to make it coordinate with grid capacity, which it could even guess indirectly by monitoring the incoming voltage.

[Ed.Kloonk]

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

I don't think it will be a problem. I have a hot tub that draws 11kW if both pumps and the heat are on full power. My clothes dryer is 5.5kW, I used to have an electric stove in the kitchen that I think was around 10kW fully utilized but that's gas now. The only EV I have direct experience living with for a while was a Tesla and in that you could set the charge current to anything you want up to the max, so if it's on a shared circuit or grid capacity is limited you can back it off. It's only a matter of software to make it coordinate with grid capacity, which it could even guess indirectly by monitoring the incoming voltage.

Yeah. I think it's a bit of bullshit that the grid can't take it. We just need to figure who it is and why. My understanding about load capacities on the grid has more to do with anticipation rather than actual heavy load. It costs money and effort to fire up an additional power source. I think that's the problem. Follow the money.

[Someone]

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

I don't think it will be a problem. I have a hot tub that draws 11kW if both pumps and the heat are on full power. My clothes dryer is 5.5kW, I used to have an electric stove in the kitchen that I think was around 10kW fully utilized but that's gas now. The only EV I have direct experience living with for a while was a Tesla and in that you could set the charge current to anything you want up to the max, so if it's on a shared circuit or grid capacity is limited you can back it off. It's only a matter of software to make it coordinate with grid capacity, which it could even guess indirectly by monitoring the incoming voltage.

Yeah. I think it's a bit of bullshit that the grid can't take it. We just need to figure who it is and why. My understanding about load capacities on the grid has more to do with anticipation rather than actual heavy load. It costs money and effort to fire up an additional power source. I think that's the problem. Follow the money.

Its a well known problem, sure you as an individual would probably get away with moving more of your energy use to electricity and the grid would cope. Just like you don't feel like you're causing the traffic when you individually choose to drive. However, if all/most or even half of transport is suddenly moved from fossil fuels to electricity (as countries are planning to do in the next 20 years) its a very big problem:
http://www.withouthotair.com/c18/page_103.shtml
https://www.iea.org/sankey/#?c=United%20States&s=Final%20consumption
or Australia if you prefer:
https://www.iea.org/sankey/#?c=Australia&s=Final%20consumption
Road transport uses more energy (annually) than the current electrical supply. So where is the plan to more the double the electrical generation? Will people play nice with their vehicle charging and only do it during off peak when there is sufficient grid/network capacity? (no, they won't, just like most people drive in peak hour and create the traffic jams).

Its going to need some new market mechanisms to price the cost of delivering that energy more fairly (supply charges based on network connection size would be one place to start, as France etc already do). Market pricing of consumption would contribute, but that remains poorly connected between wholesale and retail.

[Marco]

It's only in the last two decades that electricity use has been somewhat stable. Before that it doubled every two decades since the 60s and even faster after WW2.

Of course we were a little more progress oriented in those days. Endless lawsuits against eminent domain, endless lawsuits about permitting, species of endangered whatevers or archaeological finds in every plot of land stopping work, lack of cheap labour which doesn't care working far from home ... it's kinda hard to work at the pace the west sustained in the past.

[Ed.Kloonk]

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

I don't think it will be a problem. I have a hot tub that draws 11kW if both pumps and the heat are on full power. My clothes dryer is 5.5kW, I used to have an electric stove in the kitchen that I think was around 10kW fully utilized but that's gas now. The only EV I have direct experience living with for a while was a Tesla and in that you could set the charge current to anything you want up to the max, so if it's on a shared circuit or grid capacity is limited you can back it off. It's only a matter of software to make it coordinate with grid capacity, which it could even guess indirectly by monitoring the incoming voltage.

Yeah. I think it's a bit of bullshit that the grid can't take it. We just need to figure who it is and why. My understanding about load capacities on the grid has more to do with anticipation rather than actual heavy load. It costs money and effort to fire up an additional power source. I think that's the problem. Follow the money.

Its a well known problem, sure you as an individual would probably get away with moving more of your energy use to electricity and the grid would cope. Just like you don't feel like you're causing the traffic when you individually choose to drive. However, if all/most or even half of transport is suddenly moved from fossil fuels to electricity (as countries are planning to do in the next 20 years) its a very big problem:
http://www.withouthotair.com/c18/page_103.shtml
https://www.iea.org/sankey/#?c=United%20States&s=Final%20consumption
or Australia if you prefer:
https://www.iea.org/sankey/#?c=Australia&s=Final%20consumption
Road transport uses more energy (annually) than the current electrical supply. So where is the plan to more the double the electrical generation? Will people play nice with their vehicle charging and only do it during off peak when there is sufficient grid/network capacity? (no, they won't, just like most people drive in peak hour and create the traffic jams).

Its going to need some new market mechanisms to price the cost of delivering that energy more fairly (supply charges based on network connection size would be one place to start, as France etc already do). Market pricing of consumption would contribute, but that remains poorly connected between wholesale and retail.

I know what you're saying. But supply of power is based on economics. The grid will cope just as soon as they figure out how to charge for it. Too many ppl factor the new EV car at current supply prices.

[Someone]

If you use a 110V charger sure, which is adequate for majority of people.
But in home level 2 "fast charger" will go up to 11kW: https://insideevs.com/news/488289/chevrolet-pays-installation-cost-home-charger-bolt/ and its not that expensive to install.

So maybe they should consider discouraging installing these instead of subsidizing them? Or at least build in some grid detection, etc. to charge at optimal times, or throttle charging.

I don't think it will be a problem. I have a hot tub that draws 11kW if both pumps and the heat are on full power. My clothes dryer is 5.5kW, I used to have an electric stove in the kitchen that I think was around 10kW fully utilized but that's gas now. The only EV I have direct experience living with for a while was a Tesla and in that you could set the charge current to anything you want up to the max, so if it's on a shared circuit or grid capacity is limited you can back it off. It's only a matter of software to make it coordinate with grid capacity, which it could even guess indirectly by monitoring the incoming voltage.

Yeah. I think it's a bit of bullshit that the grid can't take it. We just need to figure who it is and why. My understanding about load capacities on the grid has more to do with anticipation rather than actual heavy load. It costs money and effort to fire up an additional power source. I think that's the problem. Follow the money.

Its a well known problem, sure you as an individual would probably get away with moving more of your energy use to electricity and the grid would cope. Just like you don't feel like you're causing the traffic when you individually choose to drive. However, if all/most or even half of transport is suddenly moved from fossil fuels to electricity (as countries are planning to do in the next 20 years) its a very big problem:
http://www.withouthotair.com/c18/page_103.shtml
https://www.iea.org/sankey/#?c=United%20States&s=Final%20consumption
or Australia if you prefer:
https://www.iea.org/sankey/#?c=Australia&s=Final%20consumption
Road transport uses more energy (annually) than the current electrical supply. So where is the plan to more the double the electrical generation? Will people play nice with their vehicle charging and only do it during off peak when there is sufficient grid/network capacity? (no, they won't, just like most people drive in peak hour and create the traffic jams).

Its going to need some new market mechanisms to price the cost of delivering that energy more fairly (supply charges based on network connection size would be one place to start, as France etc already do). Market pricing of consumption would contribute, but that remains poorly connected between wholesale and retail.

I know what you're saying. But supply of power is based on economics. The grid will cope just as soon as they figure out how to charge for it. Too many ppl factor the new EV car at current supply prices.

The grid (Australia and US) doesn't cope with existing peak demands, the current model already fails on that point. For all the talk of moving to electric transport there hasn't been any planning on how the grid will support that and where the generation will come from. Technically possible, yes, but the free market won't deliver it as the current market they play in is largely for show/theatrical (monopoly distributors, cartel generators).

You put it pretty simply:

I think it's a bit of bullshit that the grid can't take it. We just need to figure who it is and why. My understanding about load capacities on the grid has more to do with anticipation rather than actual heavy load. It costs money and effort to fire up an additional power source. I think that's the problem. Follow the money.

The grids don't have spare generation capacity, or spare carrying capacity right now (recent outages/curtailments and inability to carry more distributed solar). Neither do the grids have trajectories or plans in place to grow at the rate required by electrification of transport by 2040/2050/etc.

[bdunham7]

But supply of power is based on economics.

Unfortunately not.

But supply of power is based on economics politics.

[Ed.Kloonk]

The grids don't have spare generation capacity, or spare carrying capacity right now (recent outages/curtailments and inability to carry more distributed solar). Neither do the grids have trajectories or plans in place to grow at the rate required by electrification of transport by 2040/2050/etc.

The time from now until 2040/2050 is a long time to provide what ever cabling is needed to be just enough for normal supply. Nobody is going to do it on the off chance electric cars become a big hit.

Temporary, localized drop outs are the future because the ramp-up of loads have become orders of magnitude bigger than what we have gotten used to. I'm not disagreeing with you. But infrastructure occurs after development. Always will.

[tszaboo]

So if I know anything from the USA, there are three pretty basic solutions to any problem.
1.) Shoot it with a gun. Transformer blows up, they install a new one. Or:
2.) Sue them for millions of dollars. Or:
3.) Wave a flag, and claim you're the land of the free and chant whichever part of the constitution.

I think 1 and 2 would actually work.

[james_s]

The time from now until 2040/2050 is a long time to provide what ever cabling is needed to be just enough for normal supply. Nobody is going to do it on the off chance electric cars become a big hit.

Temporary, localized drop outs are the future because the ramp-up of loads have become orders of magnitude bigger than what we have gotten used to. I'm not disagreeing with you. But infrastructure occurs after development. Always will.

Off chance? It has already happened, electric cars already are a huge hit. The area where I live is absolutely crawling with Teslas, the model 3 is one of the top selling cars in the world.

[PaulAm]

There''s this odd belief in the US that electric utilities exist to generate and distribute electricity.  That may have been true at one point, but today their sole purpose is to generate money.

My electric bill is split between distribution and generation charges.  The distribution charges are always greater than the actual cost of electricity.  Despite having the highest (or maybe second highest) electricity rates in the country, we got nailed by a 5 day outage earlier this year from Summer storms.  "We'll do better" they say, just let us raises our rates some more!

I get oodles of ads about "green investment" and "green power" by the utility.  It's fine when they put up the farms and charge you a premium.  For local solar arrays, they are phasing out net metering and will eventually be charging for every watt that goes across their meter.  When I put up my array, I could only put up about half of my yearly demand, and I had to fight for that.

I picked up another 25KW of panels earlier this year and will eventually be moving to off-grid.  Reasonable storage is the biggest obstacle at this point, but a couple technologies look promising and there might be something available when I get there.

[Ed.Kloonk]

The time from now until 2040/2050 is a long time to provide what ever cabling is needed to be just enough for normal supply. Nobody is going to do it on the off chance electric cars become a big hit.

Temporary, localized drop outs are the future because the ramp-up of loads have become orders of magnitude bigger than what we have gotten used to. I'm not disagreeing with you. But infrastructure occurs after development. Always will.

Off chance? It has already happened, electric cars already are a huge hit. The area where I live is absolutely crawling with Teslas, the model 3 is one of the top selling cars in the world.

The question I have is how prepared was Texas in regards to being able to charge and run all those cars? The power supply seems to have coped. Unless it snows, of course. 

[Bassman59]

There''s this odd belief in the US that electric utilities exist to generate and distribute electricity.  That may have been true at one point, but today their sole purpose is to generate money.

Indeed. And they're regulated so they try to buy their way onto each state's regulatory agencies.

My electric bill is split between distribution and generation charges.  The distribution charges are always greater than the actual cost of electricity.  Despite having the highest (or maybe second highest) electricity rates in the country, we got nailed by a 5 day outage earlier this year from Summer storms.  "We'll do better" they say, just let us raises our rates some more!

The original reason for the separate generation and distribution charges was that somehow, magically, there would be "competition" in the generation market, and customers could choose who generated their power. Since there is only one set of cables that come to your house, the local provider was responsible for maintaining them.

I know there were attempts to form co-operatives for generation, but I honestly don't know where or if anyone has a choice for their power generation.

I get oodles of ads about "green investment" and "green power" by the utility.  It's fine when they put up the farms and charge you a premium.  For local solar arrays, they are phasing out net metering and will eventually be charging for every watt that goes across their meter.  When I put up my array, I could only put up about half of my yearly demand, and I had to fight for that.

The utilities are generally against customer-rooftop solar power. They certainly don't want anyone over-generating and they don't want to pay retail rates from the customers with solar who are tied into their grid. Also the utilities are our "battery" so they need the ability to spin up and spin down generators "quickly" as solar production drops and rises.

But basically they are just annoyed that they don't get the guaranteed profits that come with being a monopoly.

[NiHaoMike]

Will people play nice with their vehicle charging and only do it during off peak when there is sufficient grid/network capacity? (no, they won't, just like most people drive in peak hour and create the traffic jams).

Provide incentives to move demand off peak and it will happen to some degree. One example is Ohmconnect.

The power supply seems to have coped. Unless it snows, of course. 

Incentives to try to match demand to supply would also help a lot with that. Going further, they should also have programs that give customers the option to be first in line to be disconnected and run on generators or other backup supplies, getting paid to do so.

[rstofer]

For all the talk of moving to electric transport there hasn't been any planning on how the grid will support that and where the generation will come from. Technically possible, yes, but the free market won't deliver it as the current market they play in is largely for show/theatrical (monopoly distributors, cartel generators).

None of the electric public utility systems in the US are 'free market'.  They are all controlled by Public Utility Commissions.  The PUCs tell the utility what to do, when to do it and how much extra they can charge for the results.

Most people work during on-peak hours, that's why the demand is called 'on-peak'; buildings are up and running.  Charging at home, after work, will be during a period of reduced demand.  But, not to worry, if things get out of hand, the utilities will move to Time Of Day billing.  They already have tariffs (regulations) in place and the rates are available as an option (at least here in Northern California with PG&E).  They will just convert everybody.  For the most part, the revenue meters have already been converted to Smart Meters which are read over the power line so getting instantaneous or interval demand is trivial.  You may note that there hasn't been a meter reader (person) in the neighborhood for a decade or more.

I'm not the least bit concerned about grid capacity to charge EVs and you have never seen a utility representative worried about it either.  All you see is EV naysayers stating their opinion about the inadequacies.  EVs already have a programmable start time (or end time) as part of the firmware.  That's cool!  Tell the car you want it fully charged by the time you finish your cup of coffee in the morning (end time) and it will start the charging as required.  It remains for the car owner to have a large enough charger to get it done.

At a very high level, there must be a plan to make it work because the auto manufacturers are investing billions of dollars in new plants to build EVs.  Internal combustion vehicles simply won't be available in the near future.  Like them or not, you will eventually be driving an EV.

Gasoline here is $5/gallon and if a car gets 20 MPG, that's about $0.25/mile.  If we take 3.7 miles per kWh and $0.25/kWh this works out to $0.07/mile.  And no semiannual smog check!  And we can drive in the HOV lanes without a passenger required!

What's really cool is when you have a solar array under a power purchase agreement at, say, $0.15/kWh.  That brings the cost of driving a Bolt down to about $0.04/mile.  Try that with a gas driven SUV.  And the EV will accelerate faster from a stop light - something I do from time to time.

[rstofer]

Incentives to try to match demand to supply would also help a lot with that. Going further, they should also have programs that give customers the option to be first in line to be disconnected and run on generators or other backup supplies, getting paid to do so.

Running on generators is contradictory to the goal of reduced emissions.  That would be the absolute worst way to provide power.

Work from home is pretty popular and I'll bet houses are more efficient than office buildings because the workers pay their own utility bills.  A laptop doesn't require all the features of the modern office building.  I think I would work from the patio for about half the year.  Poke at a spreadsheet while watching the dogs run and play.  Pretty easy life!