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What if something unusual happens? Imagine there is a long blackout during those 9pm to 6am hours. It doesn't have to be the entire city, just a significant n

What if something unusual happens? Imagine there is a long blackout during those 9pm to 6am hours. It doesn't have to be the entire city, just a significant number of homes. The next morning, thousands of drivers find they don't have enough power to get to work. Thousands of cars are suddenly charging beyond the expected 9pm to 6am window. Will the grid be able to handle full daytime load in addition to this huge unexpected load? How much would it cost to upgrade the grid to worst case scenario? (entire city blackout during 9pm to 6am)?

philipkglass 9y ago
If charging shifts to early-mid morning after an overnight outage, I would expect that there's enough distribution/generation capacity to handle it. Take a look at this curve again: http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDemand http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDeman... Although demand at 7:00 AM is 5 gigawatts above the 4:00 AM nadir, it's still 15 gigawatts below the 5:00 PM peak. Since electrical generating and distribution systems are sized to handle those early-evening peaks, shifting charging some hours away from the traditional peaks (either direction, later or earlier) should allow vehicles to recharge daily without increasing daily peak demand. What about places that aren't California? Even places that have more seasonal electricity demand in the winter than in the summer, like the UK, see their daily peaks in the early evening. Peak demand hours are more about human behavior than geography. People come home after work, cook dinner, turn on lights, do chores... Traditional peak demand hours coincide with this burst of domestic activity. Scheduling charging away from the traditional peak electricity times makes more efficient use of existing infrastructure and allows peak distribution/generation capacity upgrades to be delayed and minimized even with rising adoption of home-charged EVs.

philipkglass 9y ago

If charging shifts to early-mid morning after an overnight outage, I would expect that there's enough distribution/generation capacity to handle it. Take a look at this curve again: http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDemand http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDeman... Although demand at 7:00 AM is 5 gigawatts above the 4:00 AM nadir, it's still 15 gigawatts below the 5:00 PM peak. Since electrical generating and distribution systems are sized to handle those early-evening peaks, shifting charging some hours away from the traditional peaks (either direction, later or earlier) should allow vehicles to recharge daily without increasing daily peak demand. What about places that aren't California? Even places that have more seasonal electricity demand in the winter than in the summer, like the UK, see their daily peaks in the early evening. Peak demand hours are more about human behavior than geography. People come home after work, cook dinner, turn on lights, do chores... Traditional peak demand hours coincide with this burst of domestic activity. Scheduling charging away from the traditional peak electricity times makes more efficient use of existing infrastructure and allows peak distribution/generation capacity upgrades to be delayed and minimized even with rising adoption of home-charged EVs.