5 ms·

I'm sure they'll have this sorted before their forced swotxh to EV goes in to effect.

hedora 4y ago
Sorted: I charged my car this afternoon (the amber alert signs have been warning about this all day), while we were (as a state) overproducing electricity, and set the thermostat on the house up 4 degrees 30 minutes ago. Now, the solar I overbuilt to charge the car is dumping electricity on to the grid. It'd be completely sorted, except that I can't tell the house battery (which I bought as a backup and to time-shift electricity into the car overnight) to discharge directly onto the grid. Instead, I lowered its reserve, so it will cut our demand all night (instead of peak selling for an hour or two).
- nxm 4y ago
  Nice of you to be able to afford solar panels and be home and have job flexibility to charge when you want. Not everyone is so privileged, so it still needs to be sorted
  - MontyCarloHall 4y ago
    Solar panels also cannot support apartment buildings, since the ratio of roof to living space is far too low. Batteries would also be impractical to install in apartments, where space is at a premium. One of the tradeoffs to building dense is that it makes it harder to decentralize the grid.
    - nyokodo 4y ago
      > Solar panels also cannot support apartment buildings Solar windows might help there: https://www.solarwindow.com/ https://www.solarwindow.com/
    - midoridensha 4y ago
      >One of the tradeoffs to building dense is that it makes it harder to decentralize the grid. The other side of that is that with dense living, people need dramatically less energy to begin with. Less energy for heating and cooling, and far less energy to transportation if they live close to wherever they go and can just walk there.
    - hedora 4y ago
      Community net metering solves this problem. It's not available in CA, but is in other states The apartment dwellers just buy some percentage of a solar farm, then the power company pretends that percentage of the farm's production came from the apartment's roof. Denser housing uses much less energy, so it takes much less solar per person to offset the apartment's power usage. Similarly, room can be made for batteries elsewhere, and they can be packed extremely tightly wherever they are installed. (This only works for time shifting, not individual home backup.)
    - Schroedingersat 4y ago
      Heating and cooling are the primary energy use and decrease faster than roof area increases for low rise apartments. Average apartment size is about 80m^2 so in a 3 story building that's about 30m^2 each or roughly 5kWh/day. 200W doesn't allow you to be wasteful, but it's plenty for a 1-2 bedroom apartment. Hybrid cells with slightly better efficiency and low light tolerance would get you to 10kWh/d Tokyo is around 7000 people per km^2. A 2 bedroom apartment can happily house two or three people, so with a reasonable amount of roof area per apartment you have 80-90% of your area available for not-housing. High density just means not dedicating a freestanding house worth of land area per resident to force them into cars, it doesn't need to mean highrise. Even with manila levels of density you can still get lighting, climate control (if well insulated), a washing machine, a few entertainment devices at 10-20W and basic cooking (nothing for the ground level commercial or infrastructure though) with about half your area left for not-housing. So that's some level of semi-decentralisation even in the worst case. Mid-winter in high latitudes you might struggle without long term storage, but it's not unsolvable. Batteries take up approximately 0 space. If the better part of a month's worth of energy can fit in a car it's fine.
  - fy20 4y ago
    Is there really a need for this kind of passive aggressive comment on HN?
  - hedora 4y ago
    Prices on solar are dropping fast, so wait a couple of years, and that will work itself out. Work has solar panels and chargers. Even if they didn't, there are plenty of commercial chargers across the street. Anyway, the car lets us shift about one house of normal demand into peak hours.
  - dzhiurgis 4y ago
    Solar is much cheaper and better investment than an EV
- deleted 4y ago
  [deleted]
- elzbardico 4y ago
  You’re just displacing baseload generation by overgenerating at a time of the day when demand is minimal. You’re actually one of the roots of the problem
  - hedora 4y ago
    Today, we used normal amounts (for us - AC was on instead of car charging) of power until 10am, then exported power till 5pm (the car was elsewhere, importing power to charge). For the rest of the demand emergency, we had zero gross import and export. We're back to using power over night. The next obvious thing to fix is that the battery software can't be told to avoid charging during the morning demand spike. (This would have started lowering our energy usage at 7:15 AM and let us flip to exporting power at 8:15 instead of 10am. The same thing happens every day.) Overnight baseload generation is still an issue, but at least there is an obvious path to smoothing the morning / evening spikes. We'd need a house battery with about 1.5x the car battery's capacity to get through the night while also charging the car overnight.
chrismartin 4y ago
The transition to BEVs may require more grid capacity, but BEVs also add a _lot_ of storage to the grid, which can reduce the impact of peak demand events. In circumstances like this, car owners can opt to discharge their batteries into the grid and be paid higher-than-normal rates for that energy. California is already experimenting with these programs, e.g.: https://www.utilitydive.com/news/california-approves-117m-vehicle-to-grid-pilots-in-pge-footprint/621393/ https://www.utilitydive.com/news/california-approves-117m-ve... Even without vehicle-to-grid programs, electric car owners can already choose to charge later at night when the demand peak has passed (and power is cheaper).

Sorted: I charged my car this afternoon (the amber alert signs have been warning about this all day), while we were (as a state) overproducing electricity, and set the thermostat on the house up 4 degrees 30 minutes ago. Now, the solar I overbuilt to charge the car is dumping electricity on to the grid. It'd be completely sorted, except that I can't tell the house battery (which I bought as a backup and to time-shift electricity into the car overnight) to discharge directly onto the grid. Instead, I lowered its reserve, so it will cut our demand all night (instead of peak selling for an hour or two).

nxm 4y ago
Nice of you to be able to afford solar panels and be home and have job flexibility to charge when you want. Not everyone is so privileged, so it still needs to be sorted
- MontyCarloHall 4y ago
  Solar panels also cannot support apartment buildings, since the ratio of roof to living space is far too low. Batteries would also be impractical to install in apartments, where space is at a premium. One of the tradeoffs to building dense is that it makes it harder to decentralize the grid.
  - nyokodo 4y ago
    > Solar panels also cannot support apartment buildings Solar windows might help there: https://www.solarwindow.com/ https://www.solarwindow.com/
  - midoridensha 4y ago
    >One of the tradeoffs to building dense is that it makes it harder to decentralize the grid. The other side of that is that with dense living, people need dramatically less energy to begin with. Less energy for heating and cooling, and far less energy to transportation if they live close to wherever they go and can just walk there.
  - hedora 4y ago
    Community net metering solves this problem. It's not available in CA, but is in other states The apartment dwellers just buy some percentage of a solar farm, then the power company pretends that percentage of the farm's production came from the apartment's roof. Denser housing uses much less energy, so it takes much less solar per person to offset the apartment's power usage. Similarly, room can be made for batteries elsewhere, and they can be packed extremely tightly wherever they are installed. (This only works for time shifting, not individual home backup.)
  - Schroedingersat 4y ago
    Heating and cooling are the primary energy use and decrease faster than roof area increases for low rise apartments. Average apartment size is about 80m^2 so in a 3 story building that's about 30m^2 each or roughly 5kWh/day. 200W doesn't allow you to be wasteful, but it's plenty for a 1-2 bedroom apartment. Hybrid cells with slightly better efficiency and low light tolerance would get you to 10kWh/d Tokyo is around 7000 people per km^2. A 2 bedroom apartment can happily house two or three people, so with a reasonable amount of roof area per apartment you have 80-90% of your area available for not-housing. High density just means not dedicating a freestanding house worth of land area per resident to force them into cars, it doesn't need to mean highrise. Even with manila levels of density you can still get lighting, climate control (if well insulated), a washing machine, a few entertainment devices at 10-20W and basic cooking (nothing for the ground level commercial or infrastructure though) with about half your area left for not-housing. So that's some level of semi-decentralisation even in the worst case. Mid-winter in high latitudes you might struggle without long term storage, but it's not unsolvable. Batteries take up approximately 0 space. If the better part of a month's worth of energy can fit in a car it's fine.
- fy20 4y ago
  Is there really a need for this kind of passive aggressive comment on HN?
- hedora 4y ago
  Prices on solar are dropping fast, so wait a couple of years, and that will work itself out. Work has solar panels and chargers. Even if they didn't, there are plenty of commercial chargers across the street. Anyway, the car lets us shift about one house of normal demand into peak hours.
- dzhiurgis 4y ago
  Solar is much cheaper and better investment than an EV
deleted 4y ago
[deleted]
elzbardico 4y ago
You’re just displacing baseload generation by overgenerating at a time of the day when demand is minimal. You’re actually one of the roots of the problem
- hedora 4y ago
  Today, we used normal amounts (for us - AC was on instead of car charging) of power until 10am, then exported power till 5pm (the car was elsewhere, importing power to charge). For the rest of the demand emergency, we had zero gross import and export. We're back to using power over night. The next obvious thing to fix is that the battery software can't be told to avoid charging during the morning demand spike. (This would have started lowering our energy usage at 7:15 AM and let us flip to exporting power at 8:15 instead of 10am. The same thing happens every day.) Overnight baseload generation is still an issue, but at least there is an obvious path to smoothing the morning / evening spikes. We'd need a house battery with about 1.5x the car battery's capacity to get through the night while also charging the car overnight.

chrismartin 4y ago

The transition to BEVs may require more grid capacity, but BEVs also add a _lot_ of storage to the grid, which can reduce the impact of peak demand events. In circumstances like this, car owners can opt to discharge their batteries into the grid and be paid higher-than-normal rates for that energy. California is already experimenting with these programs, e.g.: https://www.utilitydive.com/news/california-approves-117m-vehicle-to-grid-pilots-in-pge-footprint/621393/ https://www.utilitydive.com/news/california-approves-117m-ve... Even without vehicle-to-grid programs, electric car owners can already choose to charge later at night when the demand peak has passed (and power is cheaper).