4 ms·

The problem is that current batteries wear down on every charge cycle. This means that by charging and dis-charging a battery, it loses value, which means that

The problem is that current batteries wear down on every charge cycle. This means that by charging and dis-charging a battery, it loses value, which means that there is a cost for each charge cycle. I am too lazy to put numbers on this, but this cost is currently much too high to make it economically viable to use car batteries for energy storage.

kirrent 10y ago
If you continue to cycle the batteries as deeply as you were in the car this might be true but if you're willing to charge and discharge slower as well as cycle shallower the gain in life for a Li-ion battery is quite remarkable. Obviously you need more batteries but in general energy storage is just less harsh to batteries than use in cars.
ceejayoz 10y ago
That's fine, though. If your car that used to do 300 miles on a charge can only do 200, you'll probably replace it. That 200 mile charge may still be perfectly usable in a house, particularly given you can fit a couple cars worth into your basement without issues. The resulting battery cluster doesn't have to be particularly compact or light-weight.
- walrus01 10y ago
  Car applications care about kilograms per kWh stored, and cubic volume per kWh stored. Stationary batteries, not so much.
  - Cyph0n 10y ago
    Not as much, yes, but it's still important. Space is quite valuable even in a normal household.
    - Teeboo 10y ago
      Space is only at a premium because it costs more to have more space. The real question is "how much space are you willing to sacrifice for energy self-sufficiency?" In the UK, electric bills hover around $1200 a year for electric/gas households and $2000 a year for full electric. Renewable households will have a HUGE potential market. U.K. Residential market is 26 million houses. Theoretical price point of $1500 dollars (one years energy cost) = 39 billion dollar market not including the massive combined secondary services in maintenance, installation training providers, parts, etc. USA residential would be 6 times that and the provision of renewables to corporates is almost incalculable. It's an entirely new economic ecosystem divorced from petrochemical. It a price point higher than $3000 dollars we are getting into a market cap of many trillions worldwide.
      - pjc50 10y ago
        IF you can get a solar system and batteries for £1k, then that starts to look feasible. But that's a big if. I had a 3.8kW solar system put in for £5k last year and have yet to really run the numbers on savings; the payback period is 10 years of feed-in tariff cheques. If I went off-grid that would be reduced. I don't really see why I'd want to go off-grid for its own sake, I'd rather better explore the possibilities of net metering and sharing power with the rest of the city.
outworlder 10y ago
That is a true statement. However, you should not compare car batteries (usually LiFePo, LiMn or whatever it is Tesla uses) with standard laptop batteries. Electric car batteries can endure thousands of full cycles before their useful capacity drops down to 80%. That figure can be as high as tens of thousands, depending on who you ask. Suprisingly, for LiMn, temperature and age have a much greater effect on lifetime than cycles.
- Retric 10y ago
  2,000 cycles sounds great, but at just once per day that's only 5.5 years. Grid storage needs to be really cheap AND last for 20-50 years. Which is why capacitors and pumped hydro are both used. Capacitors can discharge 1,000's of times a day to maintain the proper wave form and hydro can discharge 1-3 times a day to handle changing demand. PS: The real advantage of hydro is you can invest in capacity or peak load as more or less separate things.
  - outworlder 10y ago
    Controlling for state of charge, temperature and less deep cycles, it is likely that we can achieve your figures given current tech. The question is the price. If you are not fully using them, then you need more batteries. At which point it becomes economical requires some guesses and heavy number crunching. I agree with you on hydro, gravitational storage is relatively simple to do. But it takes space. Batteries could make more sense for microgrids.
  - PakG1 10y ago
    2,000 cycles sounds great, but at just once per day that's only 5.5 years. Grid storage needs to be really cheap AND last for 20-50 years. 5.5 years is about the lifespan of servers in a datacenter. What's wrong with managing energy storage the way we manage datacenters? We don't expect servers to last 20-50 years. And no doubt, as battery tech improves, the lifespan will improve too. But the infrastructure to get good storage needs to start somewhere. Run them as datacenters for now while waiting for battery tech to get better.

kirrent 10y ago

If you continue to cycle the batteries as deeply as you were in the car this might be true but if you're willing to charge and discharge slower as well as cycle shallower the gain in life for a Li-ion battery is quite remarkable. Obviously you need more batteries but in general energy storage is just less harsh to batteries than use in cars.

ceejayoz 10y ago

That's fine, though. If your car that used to do 300 miles on a charge can only do 200, you'll probably replace it. That 200 mile charge may still be perfectly usable in a house, particularly given you can fit a couple cars worth into your basement without issues. The resulting battery cluster doesn't have to be particularly compact or light-weight.

walrus01 10y ago
Car applications care about kilograms per kWh stored, and cubic volume per kWh stored. Stationary batteries, not so much.
- Cyph0n 10y ago
  Not as much, yes, but it's still important. Space is quite valuable even in a normal household.
  - Teeboo 10y ago
    Space is only at a premium because it costs more to have more space. The real question is "how much space are you willing to sacrifice for energy self-sufficiency?" In the UK, electric bills hover around $1200 a year for electric/gas households and $2000 a year for full electric. Renewable households will have a HUGE potential market. U.K. Residential market is 26 million houses. Theoretical price point of $1500 dollars (one years energy cost) = 39 billion dollar market not including the massive combined secondary services in maintenance, installation training providers, parts, etc. USA residential would be 6 times that and the provision of renewables to corporates is almost incalculable. It's an entirely new economic ecosystem divorced from petrochemical. It a price point higher than $3000 dollars we are getting into a market cap of many trillions worldwide.
    - pjc50 10y ago
      IF you can get a solar system and batteries for £1k, then that starts to look feasible. But that's a big if. I had a 3.8kW solar system put in for £5k last year and have yet to really run the numbers on savings; the payback period is 10 years of feed-in tariff cheques. If I went off-grid that would be reduced. I don't really see why I'd want to go off-grid for its own sake, I'd rather better explore the possibilities of net metering and sharing power with the rest of the city.

outworlder 10y ago

That is a true statement. However, you should not compare car batteries (usually LiFePo, LiMn or whatever it is Tesla uses) with standard laptop batteries. Electric car batteries can endure thousands of full cycles before their useful capacity drops down to 80%. That figure can be as high as tens of thousands, depending on who you ask. Suprisingly, for LiMn, temperature and age have a much greater effect on lifetime than cycles.

Retric 10y ago
2,000 cycles sounds great, but at just once per day that's only 5.5 years. Grid storage needs to be really cheap AND last for 20-50 years. Which is why capacitors and pumped hydro are both used. Capacitors can discharge 1,000's of times a day to maintain the proper wave form and hydro can discharge 1-3 times a day to handle changing demand. PS: The real advantage of hydro is you can invest in capacity or peak load as more or less separate things.
- outworlder 10y ago
  Controlling for state of charge, temperature and less deep cycles, it is likely that we can achieve your figures given current tech. The question is the price. If you are not fully using them, then you need more batteries. At which point it becomes economical requires some guesses and heavy number crunching. I agree with you on hydro, gravitational storage is relatively simple to do. But it takes space. Batteries could make more sense for microgrids.
- PakG1 10y ago
  2,000 cycles sounds great, but at just once per day that's only 5.5 years. Grid storage needs to be really cheap AND last for 20-50 years. 5.5 years is about the lifespan of servers in a datacenter. What's wrong with managing energy storage the way we manage datacenters? We don't expect servers to last 20-50 years. And no doubt, as battery tech improves, the lifespan will improve too. But the infrastructure to get good storage needs to start somewhere. Run them as datacenters for now while waiting for battery tech to get better.