5 ms·

My Model 3 charges at ~240v/48a, which is around 11kW. At peak times in our house, say, heat on, lights on, TV on, cooking, doing laundry, we pull perhaps 3kW.

by rconti 7y ago

My Model 3 charges at ~240v/48a, which is around 11kW. At peak times in our house, say, heat on, lights on, TV on, cooking, doing laundry, we pull perhaps 3kW. Our house is pretty efficient; gas appliances, LED lights, no air conditioning, etc. The car charges after 9pm, but that's just because our rate drops then. If midnight was even cheaper, it would charge then. We don't charge every day, but if we did, it would take perhaps 1 hour. And this is for a car we drive 18,000 miles on in its first year. 3-4x the demand of a 'normal' household is not nothing, but it's not insane, either. Considering EVs don't need to charge every day, or every hour of every night, it's not that tricky to see the aggregate load as fairly similar to peak afternoon/evening hours in your average suburb as people return home from work. To be sure, if everyone started charging their EVs at 6pm, we might have a problem. Likewise, if everyone had an EV and they all clicked on at midnight, we might have a problem. But the load on the grid is not that huge from an instantaneous perspective, and can be managed by variable pricing and/or some kind of grid scheduling tech.

jgust 7y ago
I imagine a world where the electricity grid is intelligent enough to have a "conversation" with appliances to efficiently spread load across the day, more accurately plan capacity, and do it at a lower cost to consumers and the environment.
- pi-rat 7y ago
  That's happening here, my power company has a GraphQL API[1] where I can read my current consumption (5 second resolution), they also offer up the current price, including an indicator of the price level compared to how they see the rest of the day (CHEAP, NORMAL, EXPENSIVE). All houses/apartments in Norway got new smart power meters the last couple of years. They standardized on a data interface (a bus you can connect to using a RJ45 plug), so you can access your own data if you don't want to go via your power companies API. There are EV chargers[2] and other appliances (Heat pumps/ACs) that can react to this price indicator, charging your car when power is cheapest. It will also load balance based on how much the rest of your house is using, they're moving towards an "wattage" fee here, to avoid massive loads at peak hours. If you get near the limit, the car charger can slow down. Here's some images of what their app gives me[3]. It's easy to pull their data into home automation systems, here's mine[4]. You can do pretty smart stuff like: Charge my car when it's cheap, but it must be ready by 07:00. [1]: https://developer.tibber.com/docs/guides/calling-api https://developer.tibber.com/docs/guides/calling-api [2]: https://norge.tibber.com/products/easee/ https://norge.tibber.com/products/easee/ [3]: https://imgur.com/a/RYYqcjY https://imgur.com/a/RYYqcjY [4]: https://imgur.com/a/8ef0jck https://imgur.com/a/8ef0jck
  - rconti 7y ago
    Very cool! I seem to recall first reading about such plans as early as the 90s. It almost certainly wouldn't be allowed most places in the US because regulatory schemes always need approval to change, and it would be considered suspicious and an attempt to hide 'true' costs from the consumer (eg, the power provider can just change the rate any time they want, it will hurt poor people who can't afford these smart appliances, etc etc. Too bad.
    - pi-rat 7y ago
      In our case the power provider, the to the house line owner and the producer are all separate. My provides buys from the cheapest renewable offered up on NordPool. My fee to the provider is fixed (39 NOK per month). They don't get a cut of the cost per kwh to the producer. If one producer raise their price, they'll just be outbid. If they all raise their prices too much their reservoars will overflow. I pay the market price to the producer from the spot market + some percentage tax/fees to the government + line owner, and a flat fee to the provider. Makes it hard to get scammed by the power companies/providers I think. You'll get the current power source from their API or App. ATM I'm getting 100% hydro from "Kvitingen Kraftverk"[1], but that will probably change during the day. [1]: https://imgur.com/a/2uRhsZ2 https://imgur.com/a/2uRhsZ2 or https://imgur.com/a/oXeccnR https://imgur.com/a/oXeccnR (ocr translated)
      - jgust 7y ago
        Wow. The grid in the US sucks.
jaclaz 7y ago
Yes, the grid is "big enough" and (hopefully) "smart enough" to compensate peaks, the possible issue I was pointing out was not at "grid level", but rather at "local neughborhood" distribution. If the transformer serving a given number of houses is (say) 300 kVA, it remains 300 kVA, and as well the actual distribution cables/wires are rated for (still say) 100 kW each, they remain that size/gauge and both will likely need to be replaced by "beefier" stuff. BTW I took the US as an example because they - on average - consume already a very high amount of electricity pro-capita something like 12,000 kWh per year: https://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption https://en.wikipedia.org/wiki/List_of_countries_by_electrici... and so it has surely an already well dimensioned infrastructure, but besides the nordic countries (Norway/Sweden/Finland) Europe is less than half than that, Germany and France around 6,500 most of the other EU countries around or below 5,000. Besides there can be some repercussions on single homes as well, depending of course on local Laws, to give you an example here in Italy there is a "limit" at 6 kW, for constructions until 2008 there was no need of a project for the home cabling for power consumption below 6 kW while since 2008 the project is always compulsory, and <6 kW can be made by the electrician/contractor but if it goes > 6 kW it needs to be made by an electrical engineer. Since most houses are < 6kW, very few, even of the recently built ones have a project redacted by an electrical engineer and the moment you ask the provider to get (say) 10 kW you will need this project which will cost you (only the project) something in the 1,000-1,500 Euro range to which you have to sum the actual electrician/contractor work to add a line for the charger, probably another 1,000-1,500 Euro.

by rconti 7y ago

jgust 7y ago

I imagine a world where the electricity grid is intelligent enough to have a "conversation" with appliances to efficiently spread load across the day, more accurately plan capacity, and do it at a lower cost to consumers and the environment.

pi-rat 7y ago
That's happening here, my power company has a GraphQL API[1] where I can read my current consumption (5 second resolution), they also offer up the current price, including an indicator of the price level compared to how they see the rest of the day (CHEAP, NORMAL, EXPENSIVE). All houses/apartments in Norway got new smart power meters the last couple of years. They standardized on a data interface (a bus you can connect to using a RJ45 plug), so you can access your own data if you don't want to go via your power companies API. There are EV chargers[2] and other appliances (Heat pumps/ACs) that can react to this price indicator, charging your car when power is cheapest. It will also load balance based on how much the rest of your house is using, they're moving towards an "wattage" fee here, to avoid massive loads at peak hours. If you get near the limit, the car charger can slow down. Here's some images of what their app gives me[3]. It's easy to pull their data into home automation systems, here's mine[4]. You can do pretty smart stuff like: Charge my car when it's cheap, but it must be ready by 07:00. [1]: https://developer.tibber.com/docs/guides/calling-api https://developer.tibber.com/docs/guides/calling-api [2]: https://norge.tibber.com/products/easee/ https://norge.tibber.com/products/easee/ [3]: https://imgur.com/a/RYYqcjY https://imgur.com/a/RYYqcjY [4]: https://imgur.com/a/8ef0jck https://imgur.com/a/8ef0jck
- rconti 7y ago
  Very cool! I seem to recall first reading about such plans as early as the 90s. It almost certainly wouldn't be allowed most places in the US because regulatory schemes always need approval to change, and it would be considered suspicious and an attempt to hide 'true' costs from the consumer (eg, the power provider can just change the rate any time they want, it will hurt poor people who can't afford these smart appliances, etc etc. Too bad.
  - pi-rat 7y ago
    In our case the power provider, the to the house line owner and the producer are all separate. My provides buys from the cheapest renewable offered up on NordPool. My fee to the provider is fixed (39 NOK per month). They don't get a cut of the cost per kwh to the producer. If one producer raise their price, they'll just be outbid. If they all raise their prices too much their reservoars will overflow. I pay the market price to the producer from the spot market + some percentage tax/fees to the government + line owner, and a flat fee to the provider. Makes it hard to get scammed by the power companies/providers I think. You'll get the current power source from their API or App. ATM I'm getting 100% hydro from "Kvitingen Kraftverk"[1], but that will probably change during the day. [1]: https://imgur.com/a/2uRhsZ2 https://imgur.com/a/2uRhsZ2 or https://imgur.com/a/oXeccnR https://imgur.com/a/oXeccnR (ocr translated)
    - jgust 7y ago
      Wow. The grid in the US sucks.

jaclaz 7y ago

Yes, the grid is "big enough" and (hopefully) "smart enough" to compensate peaks, the possible issue I was pointing out was not at "grid level", but rather at "local neughborhood" distribution. If the transformer serving a given number of houses is (say) 300 kVA, it remains 300 kVA, and as well the actual distribution cables/wires are rated for (still say) 100 kW each, they remain that size/gauge and both will likely need to be replaced by "beefier" stuff. BTW I took the US as an example because they - on average - consume already a very high amount of electricity pro-capita something like 12,000 kWh per year: https://en.wikipedia.org/wiki/List_of_countries_by_electricity_consumption https://en.wikipedia.org/wiki/List_of_countries_by_electrici... and so it has surely an already well dimensioned infrastructure, but besides the nordic countries (Norway/Sweden/Finland) Europe is less than half than that, Germany and France around 6,500 most of the other EU countries around or below 5,000. Besides there can be some repercussions on single homes as well, depending of course on local Laws, to give you an example here in Italy there is a "limit" at 6 kW, for constructions until 2008 there was no need of a project for the home cabling for power consumption below 6 kW while since 2008 the project is always compulsory, and <6 kW can be made by the electrician/contractor but if it goes > 6 kW it needs to be made by an electrical engineer. Since most houses are < 6kW, very few, even of the recently built ones have a project redacted by an electrical engineer and the moment you ask the provider to get (say) 10 kW you will need this project which will cost you (only the project) something in the 1,000-1,500 Euro range to which you have to sum the actual electrician/contractor work to add a line for the charger, probably another 1,000-1,500 Euro.