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EVs can only be used as storage under very specific circumstances. It assumes people drive to the work in the morning have charging stations at work, and don't

EVs can only be used as storage under very specific circumstances. It assumes people drive to the work in the morning have charging stations at work, and don't commute very far. In reality lots of people don't have charging stations at work, and charge their cars in the evening when solar isn't producing. Also, there's loads of people doing errands during the day, or utility vehicles transporting cargo. These are going to be used consistently through the day and charged at night. Electric semi trucks aren't going to be helpful for grid storage. And they burn a lot more energy than a passenger sedan. And lastly, few grid operators are going to accept that their grid storage may drive away on masse during the holidays. > Suppose during a cloudy week you would have a 50GW shortfall from 6PM to 10PM and a 10GW shortfall from 12PM to 6PM, but a 20GW surplus from 8AM to 12PM During a cloudy week, you're going to have a shortfall all the time. Solar drops to 10-25% effectiveness with cloud cover: https://www.solarreviews.com/blog/do-solar-panels-work-on-cloudy-days-or-at-night#:~:text=Expect%20them%20to%20produce%2010%20to%2025%25%20of%20their%20normal,thick%20the%20cloud%20cover%20is https://www.solarreviews.com/blog/do-solar-panels-work-on-cl.... > The load during peak solar generation (~3PM) is >25GW, compared to ~20GW after midnight, and that's during the autumn rather than the summer. But again, peak demand isn't at midnight it's at 8pm. You can't just hand-wave away the challenge of meeting peak demand when intermittent sources aren't producing. > Air conditioning load aligns extremely well with solar generation. And it aligns even worse during the Winter: solar is producing the least amount of energy, cloud cover is at its greatest extent. Most homes are heated by gas, and when that gets decarbonized it's going to put even more load during the worst time of the year for renewables. Definitely, rooftop solar is a great addition and a good way to reduce load due to air conditioning. It comports with what I've been saying this whole thread: intermittent sources are good when used opportunistically to supplement a grid primarily powered by non-intermittent sources. The downsides of intermittency are too great to be used as a primary source of energy, though.

adrianN 3y ago
Every battery you put in an EV becomes a battery you can use to balance the grid when the EV is scrapped and the battery still has 80% of its capacity left.
- Manuel_D 3y ago
  80% capacity does not mean 80% of life span remaining. Degradation is not linear [1] [2], a battery that's gone through enough cycles to drop down to 80% of its capacity is very close to the end of its life just a few hundred more cycles before failure. That would drive up the costs of labor as these recycled batteries would have to be replaced once a year or even more frequently. Recycled EV batteries are popular in DIY communities because labor is free, and if they fail you still have the grid to fall back on. That's no the same case for grid operators. New LFP batteries have better economics than used EV batteries for grid storage, especially since they are both cheaper per watt hour and they have over twice the life span of most lithium-nickel-cobalt batteries used in EVs. 1. https://thundersaidenergy.com/downloads/battery-degradation-what-causes-capacity-fade/ https://thundersaidenergy.com/downloads/battery-degradation-... 2. https://escholarship.org/content/qt9372w9dp/qt9372w9dp_noSplash_010d28477889acc325376a830685adf8.pdf https://escholarship.org/content/qt9372w9dp/qt9372w9dp_noSpl...
  - adrianN 3y ago
    So you're saying your point about every battery going into an EV is completely irrelevant because grid batteries will most likely use different chemistries than EV batteries? That's fine too.
    - Manuel_D 3y ago
      The point is, recycled EV batteries are not effective for grid storage and don't present a solution to the scaling issues for grid storage batteries.
AnthonyMouse 3y ago
> It assumes people drive to the work in the morning have charging stations at work That's a pretty reasonable assumption once electric cars are the majority of cars. > and don't commute very far. There are popular electric cars with a range on the order of 300 miles. The average commute is 41 miles round trip. > Also, there's loads of people doing errands during the day, or utility vehicles transporting cargo. The average person does not drive 300 miles a day in total, and so does not need to charge more than once a day in total. Utility vehicles will have larger batteries and more range, and will strongly prefer to charge during daylight because charging from solar will cost less. > And lastly, few grid operators are going to accept that their grid storage may drive away on masse during the holidays. It's storing the energy that the vehicle itself will use. If the vehicle leaves the area then so does its demand for electricity. > During a cloudy week, you're going to have a shortfall all the time. Solar drops to 10-25% effectiveness with cloud cover If your grid has 40GW of nuclear and 60GW average of solar (which generates 120GW during daylight) then the 120GW drops to 30GW and you have 70GW of generation, which could be less than the demand before noon. You can also run the peaker plants even though you already had a surplus in those hours so you can put even more into the batteries to have enough later in the day. > But again, peak demand isn't at midnight it's at 8pm. You can't just hand-wave away the challenge of meeting peak demand when intermittent sources aren't producing. Suppose you have enough nuclear to meet the demand at midnight, which is enough to meet half of the demand at 8PM. So now you need to satisfy the other half from batteries for four hours, because before 6PM the sun is still up and after 10PM the demand falls off to what you're getting from nuclear. So you don't need enough batteries to satisfy all of the demand for the 12 hours when there is no sunlight, you only need enough to satisfy half of the demand for those four hours. > And it aligns even worse during the Winter: solar is producing the least amount of energy, cloud cover is at its greatest extent. But there is more wind in the winter, and at night, when there is more demand for heating. And one of the ways to decarbonize heating in cities is nuclear with cogeneration. Then you're not using electricity for heat, you're using the waste heat from the reactors, which chops off a large chunk of even the existing nighttime load.
- Manuel_D 3y ago
  Again, electric vehicles only work as storage if people can charge their cars at work, drive home, and then tap that storage over night. Many vehicles aren't being used for commuting, they're used for work or running errands. They're going to be used during the day and charged at night. People aren't just going to become nocturnal in order to charge their cars. Someone who drives to work in the morning, goes shopping during the day, and picks kids up in the evening isn't going to be able to do all these chores at night. What happens if someone's car is discharged over night right before a trip to Grandma's and now they don't have enough range? They're going to be pissed and stop letting the grid tap into their car. > If your grid has 40GW of nuclear and 60GW average of solar (which generates 120GW during daylight) then the 120GW drops to 30GW and you have 70GW of generation If you've got 50GW deficit over a week of cloud cover you need 4,200 GWh of storage to offset that. Consider that in many parts of the world, cloud cover can be present for a month or longer. These are absolutely massive storage figures. The latter is about ten times the annual global battery output. And energy demand is much higher than 120 GW. US electricity demand is 500 GW. Global electricity demand is 3,300 GW. > Suppose you have enough nuclear to meet the demand at midnight, which is enough to meet half of the demand at 8PM. It's enough to satisfy 70% of the demand at 8PM. And since nuclear is just as cheap to run at 100% capacity all day long, it's better to scrap the bulk of your renewables because the nuclear plants make them redundant. > But there is more wind in the winter, and at night, when there is more demand for heating. This depends on geography. On the west coast, it's the opposite: wind produces the least energy during winter. https://www.eia.gov/todayinenergy/detail.php?id=20112 https://www.eia.gov/todayinenergy/detail.php?id=20112

adrianN 3y ago

Every battery you put in an EV becomes a battery you can use to balance the grid when the EV is scrapped and the battery still has 80% of its capacity left.

Manuel_D 3y ago
80% capacity does not mean 80% of life span remaining. Degradation is not linear [1] [2], a battery that's gone through enough cycles to drop down to 80% of its capacity is very close to the end of its life just a few hundred more cycles before failure. That would drive up the costs of labor as these recycled batteries would have to be replaced once a year or even more frequently. Recycled EV batteries are popular in DIY communities because labor is free, and if they fail you still have the grid to fall back on. That's no the same case for grid operators. New LFP batteries have better economics than used EV batteries for grid storage, especially since they are both cheaper per watt hour and they have over twice the life span of most lithium-nickel-cobalt batteries used in EVs. 1. https://thundersaidenergy.com/downloads/battery-degradation-what-causes-capacity-fade/ https://thundersaidenergy.com/downloads/battery-degradation-... 2. https://escholarship.org/content/qt9372w9dp/qt9372w9dp_noSplash_010d28477889acc325376a830685adf8.pdf https://escholarship.org/content/qt9372w9dp/qt9372w9dp_noSpl...
- adrianN 3y ago
  So you're saying your point about every battery going into an EV is completely irrelevant because grid batteries will most likely use different chemistries than EV batteries? That's fine too.
  - Manuel_D 3y ago
    The point is, recycled EV batteries are not effective for grid storage and don't present a solution to the scaling issues for grid storage batteries.

AnthonyMouse 3y ago

> It assumes people drive to the work in the morning have charging stations at work That's a pretty reasonable assumption once electric cars are the majority of cars. > and don't commute very far. There are popular electric cars with a range on the order of 300 miles. The average commute is 41 miles round trip. > Also, there's loads of people doing errands during the day, or utility vehicles transporting cargo. The average person does not drive 300 miles a day in total, and so does not need to charge more than once a day in total. Utility vehicles will have larger batteries and more range, and will strongly prefer to charge during daylight because charging from solar will cost less. > And lastly, few grid operators are going to accept that their grid storage may drive away on masse during the holidays. It's storing the energy that the vehicle itself will use. If the vehicle leaves the area then so does its demand for electricity. > During a cloudy week, you're going to have a shortfall all the time. Solar drops to 10-25% effectiveness with cloud cover If your grid has 40GW of nuclear and 60GW average of solar (which generates 120GW during daylight) then the 120GW drops to 30GW and you have 70GW of generation, which could be less than the demand before noon. You can also run the peaker plants even though you already had a surplus in those hours so you can put even more into the batteries to have enough later in the day. > But again, peak demand isn't at midnight it's at 8pm. You can't just hand-wave away the challenge of meeting peak demand when intermittent sources aren't producing. Suppose you have enough nuclear to meet the demand at midnight, which is enough to meet half of the demand at 8PM. So now you need to satisfy the other half from batteries for four hours, because before 6PM the sun is still up and after 10PM the demand falls off to what you're getting from nuclear. So you don't need enough batteries to satisfy all of the demand for the 12 hours when there is no sunlight, you only need enough to satisfy half of the demand for those four hours. > And it aligns even worse during the Winter: solar is producing the least amount of energy, cloud cover is at its greatest extent. But there is more wind in the winter, and at night, when there is more demand for heating. And one of the ways to decarbonize heating in cities is nuclear with cogeneration. Then you're not using electricity for heat, you're using the waste heat from the reactors, which chops off a large chunk of even the existing nighttime load.

Manuel_D 3y ago
Again, electric vehicles only work as storage if people can charge their cars at work, drive home, and then tap that storage over night. Many vehicles aren't being used for commuting, they're used for work or running errands. They're going to be used during the day and charged at night. People aren't just going to become nocturnal in order to charge their cars. Someone who drives to work in the morning, goes shopping during the day, and picks kids up in the evening isn't going to be able to do all these chores at night. What happens if someone's car is discharged over night right before a trip to Grandma's and now they don't have enough range? They're going to be pissed and stop letting the grid tap into their car. > If your grid has 40GW of nuclear and 60GW average of solar (which generates 120GW during daylight) then the 120GW drops to 30GW and you have 70GW of generation If you've got 50GW deficit over a week of cloud cover you need 4,200 GWh of storage to offset that. Consider that in many parts of the world, cloud cover can be present for a month or longer. These are absolutely massive storage figures. The latter is about ten times the annual global battery output. And energy demand is much higher than 120 GW. US electricity demand is 500 GW. Global electricity demand is 3,300 GW. > Suppose you have enough nuclear to meet the demand at midnight, which is enough to meet half of the demand at 8PM. It's enough to satisfy 70% of the demand at 8PM. And since nuclear is just as cheap to run at 100% capacity all day long, it's better to scrap the bulk of your renewables because the nuclear plants make them redundant. > But there is more wind in the winter, and at night, when there is more demand for heating. This depends on geography. On the west coast, it's the opposite: wind produces the least energy during winter. https://www.eia.gov/todayinenergy/detail.php?id=20112 https://www.eia.gov/todayinenergy/detail.php?id=20112