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No way. People can't get lousy fiber pulled to their houses and you're talking about multimegawatt electricity supply.

by lstodd 6y ago

londons_explore 6y ago
I'm talking about slow chargers - the kind that are 60 amps or so AC. The kind that require no expensive electronics in the charger. The kind that'll take 12 hours for a full charge. Fast DC chargers will always cost more due to the need for expensive power electronics.
- lstodd 6y ago
  Even just +7 kVA per house means a complete rebuild of the grid. 1 MW would be enough for just ~150 chargers. And where would you get that megawatt at night? More base load, which means nuclear or fossil which means less niche for solar because no one would shut down such amount of base load generation each day. Besides 60 amps isn't exactly cheap in electronics. It might not require active cooling for the cable and the battery, that's true.
  - Reason077 6y ago
    > "Even just +7 kVA per house means a complete rebuild of the grid." Only if every car in your neighbourhood is plugged in and pulling 7 kW at the same time. Smart charging solves this, by reducing charging during demand peaks (ie: 6pm when everyone is arriving home from work and plugging in at the same time), and increasing it later in the night when more capacity is available.
    - lstodd 6y ago
      However you slice it, you have to deliver say 40KWh to that many cars overnight, or they fail to charge and thus are useless. So the grid has to handle that and even if you can get rid of extreme peaks with "smartness", you can't lower the cables and switches ratings much.
      - Reason077 6y ago
        First of all, the average car does not need 40 kWh every day. The average driver in the USA drives 13,500 miles per year (far more than the average driver in the UK/Europe!) That's about 37 miles per day, so about 12.5 kWh per night on average at ~3 miles per kWh. And remember, those who are driving long distance are probably going to be using fast chargers on-route, so their domestic charging demand will be lower. Secondly, even if they did need 40 kWh every night, that only equates to 4 kW over a 10 hour charging cycle. Easily manageable by avoiding the typical late afternoon / early evening peaks. Most grids have a lot of spare capacity between, say, 9PM and 7AM.
        lstodd 6y ago
        You fail to take into account inefficiencies in transmission and charging. That would multiply required input by a factor of two or three, depending where you measure it. So no. Switch most commute to electric - then at first grid goes down, then power plants struggle. "Most grids have a lot of spare capacity between, say, 9PM and 7AM" - that's not the grids we're talking about. HV circuits might not feel it, but something laid down for a suburb was scrupulously designed to carry only just enough, because it's basically burying refined metal, be it copper or aluminium. There is no spare even 4KW for every house and never has been because that would have cost more in about everything - meters, cables, multiple stages of step-down transformers, transmission lines, generation. Electicity is not free, never has been, and distibution costs are surprisingly a very important consideration.
        Reason077 6y ago
        > "There is no spare even 4KW for every house and never has been" Yes, there is. It's just the timing that matters. Domestic electricity demand during off-peak overnight hours is as little as 1/3 as it is at peak time. If all those houses can run 4 kW of air conditioning, or heating, or electric ovens at 6PM, then there is 4 kW to spare at 2AM. This issue has actually been studied in some detail by the UK's National Grid. The conclusion was that additional demand from millions of electric vehicles would cause issues if they all were charged at peak times. But, provided demand can be managed, existing grid infrastructure can cope with an entirely electric vehicle fleet with modest investments in the coming years/decades. Fun fact: UK grid demand used to be significantly higher than it is today. It peaked at 62 GW in 2002, but it now rarely gets above 45 GW, despite significant population growth! Much of this reduction in demand is due to improved energy efficiency. If we could handle 62 GW in 2002, then there's no reason that we can't handle 62 GW again in, say, 2042.
- yholio 6y ago
  The issue is not power electronics, but power supply. You might have a 60 Amps grid supply, or even a 100Amps split phase 120/240V as is typical for newer US homes, which allows drawing 24KW from the grid at full power. Your neighbor might have the same. But that doesn't mean everybody in your neighborhood can draw 24KW all night long. Those are maximal currents for intermittent loads like heaters, clothes driers etc. You might have a single 100KVA polemount transformer suppling a whole street and a single 15KV / 300Amp line servicing a whole neighborhood. When everybody attempts to draw even 5-10KW in the air-conditioning season, you get circuit breaks because the main feed is incapable of supplying sufficient power. The upgrading will be done but it will take a decade or more, especially considering the push from local municipalities towards buried power feeds which are very expensive.
  - adrianN 6y ago
    Electric cars consume about 20kWh/100km. If your whole neighborhood needs to draw double digit kilowatts for 10h a night, you live in a neighborhood of long distance truck drivers.
    - im3w1l 6y ago
      Maybe it doesn't happen every night, but only some nights. Say when everyone comes home from thanksgiving with empty batteries.
      - adrianN 6y ago
        If everyone wants to fill up their tank at once, the gas stations run out of gas. This doesn't happen with any regularity, which I take as an indicator that the scenario you're describing is very rare.
        im3w1l 6y ago
        The gas system has buffering and slack at many levels. Cars store more mileage. Gas stations have a buffer. Gas stations can request more trucks come refill much easier than a grid can be upgraded. I don't think you proved anything.

No way. People can't get lousy fiber pulled to their houses and you're talking about multimegawatt electricity supply.

by lstodd 6y ago

No way. People can't get lousy fiber pulled to their houses and you're talking about multimegawatt electricity supply.

I'm talking about slow chargers - the kind that are 60 amps or so AC. The kind that require no expensive electronics in the charger. The kind that'll take 12 hours for a full charge. Fast DC chargers will always cost more due to the need for expensive power electronics.

lstodd 6y ago
Even just +7 kVA per house means a complete rebuild of the grid. 1 MW would be enough for just ~150 chargers. And where would you get that megawatt at night? More base load, which means nuclear or fossil which means less niche for solar because no one would shut down such amount of base load generation each day. Besides 60 amps isn't exactly cheap in electronics. It might not require active cooling for the cable and the battery, that's true.
- Reason077 6y ago
  > "Even just +7 kVA per house means a complete rebuild of the grid." Only if every car in your neighbourhood is plugged in and pulling 7 kW at the same time. Smart charging solves this, by reducing charging during demand peaks (ie: 6pm when everyone is arriving home from work and plugging in at the same time), and increasing it later in the night when more capacity is available.
  - lstodd 6y ago
    However you slice it, you have to deliver say 40KWh to that many cars overnight, or they fail to charge and thus are useless. So the grid has to handle that and even if you can get rid of extreme peaks with "smartness", you can't lower the cables and switches ratings much.
    - Reason077 6y ago
      First of all, the average car does not need 40 kWh every day. The average driver in the USA drives 13,500 miles per year (far more than the average driver in the UK/Europe!) That's about 37 miles per day, so about 12.5 kWh per night on average at ~3 miles per kWh. And remember, those who are driving long distance are probably going to be using fast chargers on-route, so their domestic charging demand will be lower. Secondly, even if they did need 40 kWh every night, that only equates to 4 kW over a 10 hour charging cycle. Easily manageable by avoiding the typical late afternoon / early evening peaks. Most grids have a lot of spare capacity between, say, 9PM and 7AM.
      - lstodd 6y ago
        You fail to take into account inefficiencies in transmission and charging. That would multiply required input by a factor of two or three, depending where you measure it. So no. Switch most commute to electric - then at first grid goes down, then power plants struggle. "Most grids have a lot of spare capacity between, say, 9PM and 7AM" - that's not the grids we're talking about. HV circuits might not feel it, but something laid down for a suburb was scrupulously designed to carry only just enough, because it's basically burying refined metal, be it copper or aluminium. There is no spare even 4KW for every house and never has been because that would have cost more in about everything - meters, cables, multiple stages of step-down transformers, transmission lines, generation. Electicity is not free, never has been, and distibution costs are surprisingly a very important consideration.
        Reason077 6y ago
        > "There is no spare even 4KW for every house and never has been" Yes, there is. It's just the timing that matters. Domestic electricity demand during off-peak overnight hours is as little as 1/3 as it is at peak time. If all those houses can run 4 kW of air conditioning, or heating, or electric ovens at 6PM, then there is 4 kW to spare at 2AM. This issue has actually been studied in some detail by the UK's National Grid. The conclusion was that additional demand from millions of electric vehicles would cause issues if they all were charged at peak times. But, provided demand can be managed, existing grid infrastructure can cope with an entirely electric vehicle fleet with modest investments in the coming years/decades. Fun fact: UK grid demand used to be significantly higher than it is today. It peaked at 62 GW in 2002, but it now rarely gets above 45 GW, despite significant population growth! Much of this reduction in demand is due to improved energy efficiency. If we could handle 62 GW in 2002, then there's no reason that we can't handle 62 GW again in, say, 2042.
yholio 6y ago
The issue is not power electronics, but power supply. You might have a 60 Amps grid supply, or even a 100Amps split phase 120/240V as is typical for newer US homes, which allows drawing 24KW from the grid at full power. Your neighbor might have the same. But that doesn't mean everybody in your neighborhood can draw 24KW all night long. Those are maximal currents for intermittent loads like heaters, clothes driers etc. You might have a single 100KVA polemount transformer suppling a whole street and a single 15KV / 300Amp line servicing a whole neighborhood. When everybody attempts to draw even 5-10KW in the air-conditioning season, you get circuit breaks because the main feed is incapable of supplying sufficient power. The upgrading will be done but it will take a decade or more, especially considering the push from local municipalities towards buried power feeds which are very expensive.
- adrianN 6y ago
  Electric cars consume about 20kWh/100km. If your whole neighborhood needs to draw double digit kilowatts for 10h a night, you live in a neighborhood of long distance truck drivers.
  - im3w1l 6y ago
    Maybe it doesn't happen every night, but only some nights. Say when everyone comes home from thanksgiving with empty batteries.
    - adrianN 6y ago
      If everyone wants to fill up their tank at once, the gas stations run out of gas. This doesn't happen with any regularity, which I take as an indicator that the scenario you're describing is very rare.
      - im3w1l 6y ago
        The gas system has buffering and slack at many levels. Cars store more mileage. Gas stations have a buffer. Gas stations can request more trucks come refill much easier than a grid can be upgraded. I don't think you proved anything.