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If I understood it correctly, one big problem is that some "clean" energy like solar and wind don't accumulate, i.e., it must be used as it is produced, and tha

If I understood it correctly, one big problem is that some "clean" energy like solar and wind don't accumulate, i.e., it must be used as it is produced, and that doesn't scale well with spikes in consume during the night and so on. In that sense, using electric cars as batteries seems interesting. They would charge during the day and discharge during the night. The fact that they move around is a bonus :)

dogma1138 10y ago
>In that sense, using electric cars as batteries seems interesting. No, it really does not seem interesting, it seems like a terrible idea up there with solar freaking roadways. Car batteries have a completely different profile than long term storage batteries. Different voltage, charge and discharge cycles and drain and output attenuation. While Tesla does sell a "power wall" it has nothing to do with the car batteries they use, it's a completely different beast and even that is not optimised that well compared to dedicated household level battery storage. >They would charge during the day and discharge during the night. Nighttime electrical use is when it's at it's lowest, not to mention that why would you want your car to be discharging at night? You need to drive it in the morning, and if you want to save power you want to charge it at night not to add to the day time use so you want a full battery in the morning. >The fact that they move around is a bonus :) A bonus for what? having a system that is unpredictable/unreliable because the location, availability and density of your storage changes constantly?
- ageofwant 10y ago
  Long term storage ? Since when is 12h drain/fill cycles "long term". The Tesla power wall is functionally identical to its car batteries, using the same Li ion battery tech. Optimisation is a matter of power profile programming, modern converters are very capable. What makes this tech more interesting is the fact that you could buy cheap electricity from the garage you park you car during the day (the one with the massive solar roof, close to cheap to maintain central transmission lines). A million grid-connected batteries represents a very resilient power system with interesting real-time energy markets on top. It is very interesting indeed.
IMTDb 10y ago
Electrical energy does not accumulate: it's a movement of electrons, and we can't "store" a movement. The best we can do to "store electricity" (note the quote) is to create a system that can easily produce this movement of electrons as needed. Here are two examples : - A chemical reaction that creates a movement of electric charges during the reaction. This is how your regular batteries work. Rechargeable batteries like the one found is Tesla cars, your laptop, ... use a chemical reaction that can be "rewinded" if an opposite movement of electrons is forced by an external system. - A big hole in the ground is divided in two parts with dam that is fully closed. Both parts are half full of water. To recharge the "battery", the water of the left part of the hole is pumped in the right part of the hole using electrical power. When electrical power is needed, the dam is open, and water is forced by gravity from the right part of the hole to the left part. the water passes through a turbine that generates power that can be injected into the grid. There are dozens of ways to create batteries like these, but none are actually storing electrical power. Please also note that there are no perfect batteries : you always use more energy to recharge the battery than you get when using it.
- c22 10y ago
  This is needlessly pedantic. As you implied we can't "store" any type of energy, electric or otherwise, but this is commonly accepted terminology for creating and exploiting an energy potential. I can't "store" mp3s on my iPod either, but no one is confused or deceived by the terminology.
  - IMTDb 10y ago
    The original comment I am replying to seems to oppose clean energy that don't accumulate VS nuclear power which would accumulate to be used later. At least that's how I understood it. I just wanted to point out that there is no difference there between nuclear and solar/wind.

dogma1138 10y ago

>In that sense, using electric cars as batteries seems interesting. No, it really does not seem interesting, it seems like a terrible idea up there with solar freaking roadways. Car batteries have a completely different profile than long term storage batteries. Different voltage, charge and discharge cycles and drain and output attenuation. While Tesla does sell a "power wall" it has nothing to do with the car batteries they use, it's a completely different beast and even that is not optimised that well compared to dedicated household level battery storage. >They would charge during the day and discharge during the night. Nighttime electrical use is when it's at it's lowest, not to mention that why would you want your car to be discharging at night? You need to drive it in the morning, and if you want to save power you want to charge it at night not to add to the day time use so you want a full battery in the morning. >The fact that they move around is a bonus :) A bonus for what? having a system that is unpredictable/unreliable because the location, availability and density of your storage changes constantly?

ageofwant 10y ago
Long term storage ? Since when is 12h drain/fill cycles "long term". The Tesla power wall is functionally identical to its car batteries, using the same Li ion battery tech. Optimisation is a matter of power profile programming, modern converters are very capable. What makes this tech more interesting is the fact that you could buy cheap electricity from the garage you park you car during the day (the one with the massive solar roof, close to cheap to maintain central transmission lines). A million grid-connected batteries represents a very resilient power system with interesting real-time energy markets on top. It is very interesting indeed.

IMTDb 10y ago

Electrical energy does not accumulate: it's a movement of electrons, and we can't "store" a movement. The best we can do to "store electricity" (note the quote) is to create a system that can easily produce this movement of electrons as needed. Here are two examples : - A chemical reaction that creates a movement of electric charges during the reaction. This is how your regular batteries work. Rechargeable batteries like the one found is Tesla cars, your laptop, ... use a chemical reaction that can be "rewinded" if an opposite movement of electrons is forced by an external system. - A big hole in the ground is divided in two parts with dam that is fully closed. Both parts are half full of water. To recharge the "battery", the water of the left part of the hole is pumped in the right part of the hole using electrical power. When electrical power is needed, the dam is open, and water is forced by gravity from the right part of the hole to the left part. the water passes through a turbine that generates power that can be injected into the grid. There are dozens of ways to create batteries like these, but none are actually storing electrical power. Please also note that there are no perfect batteries : you always use more energy to recharge the battery than you get when using it.

c22 10y ago
This is needlessly pedantic. As you implied we can't "store" any type of energy, electric or otherwise, but this is commonly accepted terminology for creating and exploiting an energy potential. I can't "store" mp3s on my iPod either, but no one is confused or deceived by the terminology.
- IMTDb 10y ago
  The original comment I am replying to seems to oppose clean energy that don't accumulate VS nuclear power which would accumulate to be used later. At least that's how I understood it. I just wanted to point out that there is no difference there between nuclear and solar/wind.