this #lead-acid battery (model Trojan 27TMX) stores supposedly 105 amp-hours of #energy at 12 volts, but really more like 73 amp-hours, which works out to 880 watt-hours or 3.2 MJ; it can manage 530 amps at 0°. It weighs 25 kg and costs AR$5100, about US$340, giving about 9.3 kJ/US$ or reciprocally US$108/MJ. Although this is more than twice the cost in the US, it’s still a bearable cost. The battery lifetime is given as 750 full charges.
on 02016-07-11household scale #energy storage to smooth out intermittency of common renewable power sources like #solar; #batteries are best. 10m³ of #lead-acid batteries weigh 19 tons and store 750 kWh (2.7 GJ), but they cost US$150/kWh (US$41/MJ). 360 kg lifted by 3 m is required to store 3 Wh (at 29J/kg at 3 m), about 500× less energy density per mass than lead-acid batteries, so gravitational energy storage is impractical. #Flywheel storage is practical at a multi-meter scale even with steel, but the construction is expensive. Compressed air at a multi-meter scale (10m³) is practical, but again expensive.
on 02015-11-16