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Unfortunate fact is that battery charging tends to halfway overlap with hours you would want to drain the cars a bit. People want their vehicles predictably us

Unfortunate fact is that battery charging tends to halfway overlap with hours you would want to drain the cars a bit. People want their vehicles predictably usable, which is why any idea dependent on using car batteries as actual power smoothing will fail.

ben_w 4y ago
Most people don't drive enough miles per day to drain batteries even close to 100%, so that isn't a critical issue. This is why car-mounted PV is being demonstrated, even though for normal-looking cars that PV will only add 10-20 miles range per day on batteries of 100-200 miles — those extra miles are 80-90% of the average vehicle's daily milage. Also, as batteries can be charged wherever and whenever there is electricity, we can simply install PV enough for the daylight hours to produce the energy desired for both daylight and twilight/nighttime and then just charge daytime and discharge nighttime even though it's probably the other way around wherever you are because currently demand is generally lower relative to supply at night and therefore the electricity is generally cheaper at night. And the same batteries can easily be given a second life, after degrading too much for car use and before refurbishment/recycling to make them suitable for car use again, as fixed batteries. And again, this is just presuming only PV, not wind which reduces the variance in supply, and not any of the other things I listed which don't get affected by weather at all.
- theshrike79 4y ago
  > And the same batteries can easily be given a second life, after degrading too much for car use and before refurbishment/recycling to make them suitable for car use again, as fixed batteries. This is the thing people tend to forget. Even if a battery is "useless" for an EV, meaning that it has degraded to 60-70%, it still has 25-50kWh of usable capacity as-is. And that's enough to run a house for 12-48 hours depending on how power-hungry your appliances are.

ben_w 4y ago

Most people don't drive enough miles per day to drain batteries even close to 100%, so that isn't a critical issue. This is why car-mounted PV is being demonstrated, even though for normal-looking cars that PV will only add 10-20 miles range per day on batteries of 100-200 miles — those extra miles are 80-90% of the average vehicle's daily milage. Also, as batteries can be charged wherever and whenever there is electricity, we can simply install PV enough for the daylight hours to produce the energy desired for both daylight and twilight/nighttime and then just charge daytime and discharge nighttime even though it's probably the other way around wherever you are because currently demand is generally lower relative to supply at night and therefore the electricity is generally cheaper at night. And the same batteries can easily be given a second life, after degrading too much for car use and before refurbishment/recycling to make them suitable for car use again, as fixed batteries. And again, this is just presuming only PV, not wind which reduces the variance in supply, and not any of the other things I listed which don't get affected by weather at all.

theshrike79 4y ago
> And the same batteries can easily be given a second life, after degrading too much for car use and before refurbishment/recycling to make them suitable for car use again, as fixed batteries. This is the thing people tend to forget. Even if a battery is "useless" for an EV, meaning that it has degraded to 60-70%, it still has 25-50kWh of usable capacity as-is. And that's enough to run a house for 12-48 hours depending on how power-hungry your appliances are.