4 ms·

Taking your numbers for granted, that would be just the ongoing replacement costs, not the capital costs. Current capital costs are about $200/kWh. Daily globa

Taking your numbers for granted, that would be just the ongoing replacement costs, not the capital costs. Current capital costs are about $200/kWh. Daily global energy use is about 400 TWh. That would be an 80000 trillion dollar battery. The number is so large we just can't build it, so it's actually infinite. It also doesn't take into account land costs, because these batteries will take huge amounts of space. It's also only for 1 day, and there will surely be multiple days where wind and sun are below 20% output, so you'll need to accept periodic blackouts.

ben_w 7y ago
1. It’s $145/kWh 2. You’re counting all energy use, I’m just counting electricity 3. $200/kWh * 400 TWh is $80 Tr not $80,000 Tr 4. That’s not “just one day”, it is >4,000 days because the battery can be recharged that many times 5. Even if you forced everyone to accept blackouts until this would be completed (won’t happen), they would occur at night.
- deleted 7y ago
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- akvadrako 7y ago
  You're right about #3 - it would be hundreds of trillions, not thousands.
  - ben_w 7y ago
    6. Your 400 TWh number is for 24 hours, not “simultaneous no wind and nighttime”, so even if you include all power and not just electricity (even though power intended for non-electrical use can be stored in other things than batteries) you’re now talking $40 Tr, worldwide, spread over however many years you want to build this collection of batteries. Except that’s $29 Tr when using the cheapest currently available batteries that I’ve seen. 7. The lifetime cost of the battery and a PV cell is cheaper than the fuel in a coal plant even when the cost of the coal plant itself has been written off, so each incremental step of that combination is still profitable compared to that particularly fossil fuel. I’m not sure about the cost of wind or other fossil fuels, but the combined cost of PV+battery that anything else has to beat is 5¢/kWh. EDIT: 8. Land costs. The energy density of LiIon batteries is “250-693 Wh/L”. A high efficiency 1 m^2 sun-tracking PV panel with the lowest energy density battery would produce up to 400 W * 12 hours = 4800 Wh = 19.2 litres = a layer behind the PV panel of 1.92 cm thickness. Why is this supposed to be a criticism?

ben_w 7y ago

1. It’s $145/kWh 2. You’re counting all energy use, I’m just counting electricity 3. $200/kWh * 400 TWh is $80 Tr not $80,000 Tr 4. That’s not “just one day”, it is >4,000 days because the battery can be recharged that many times 5. Even if you forced everyone to accept blackouts until this would be completed (won’t happen), they would occur at night.

deleted 7y ago
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akvadrako 7y ago
You're right about #3 - it would be hundreds of trillions, not thousands.
- ben_w 7y ago
  6. Your 400 TWh number is for 24 hours, not “simultaneous no wind and nighttime”, so even if you include all power and not just electricity (even though power intended for non-electrical use can be stored in other things than batteries) you’re now talking $40 Tr, worldwide, spread over however many years you want to build this collection of batteries. Except that’s $29 Tr when using the cheapest currently available batteries that I’ve seen. 7. The lifetime cost of the battery and a PV cell is cheaper than the fuel in a coal plant even when the cost of the coal plant itself has been written off, so each incremental step of that combination is still profitable compared to that particularly fossil fuel. I’m not sure about the cost of wind or other fossil fuels, but the combined cost of PV+battery that anything else has to beat is 5¢/kWh. EDIT: 8. Land costs. The energy density of LiIon batteries is “250-693 Wh/L”. A high efficiency 1 m^2 sun-tracking PV panel with the lowest energy density battery would produce up to 400 W * 12 hours = 4800 Wh = 19.2 litres = a layer behind the PV panel of 1.92 cm thickness. Why is this supposed to be a criticism?