3 ms·

Tesla battery pack here I come!

• manicdee 11y ago
  Just remember to calculate the cost per kWh of electricity you extract from your battery. This comes down to roughly: $/kWh = $cost of installation / (kWh capacity * cycles lifetime * efficiency) So if the Powerwall costs $5000 for a 7kWh capacity with a lifetime of about 3600 charge cycles at 80% efficiency, you're looking at $0.25/kWh. If the difference between lowest and highest prices is lower than that, you're better off not buying the Powerwall in the first place. Once the difference between minimum and maximum price per kWh of electricity from the grid exceeds the $/kWh of the battery, you have an economic incentive to install the battery. As the price of batteries comes down, companies will invest in battery peaking plants to take advantage of pricing on the energy market. Those bulk battery installations will limit the spread of wholesale time-of-day pricing such that it will never be economically sensible for home users to install batteries as a cost saving device based on retail time-of-day pricing. Domestic units will necessarily cost more per storage/output capacity than commercial units. For the meantime, installing batteries for your home will only be useful for people who have problems with reliable access to electricity (e.g.: you have frequent brown-outs). There are advances on the horizon thanks to new battery assembly technology, and Tesla Energy's "Gigafactory" bringing economies of scale and integration into battery manufacturing, with an aim of reducing battery manufacturing costs around 30% for the former and 20% for the latter. There are also some theoretical (and in some cases lab proven) technologies to extend Lithium battery lifetimes to "forever". These all alter the numbers in the equation above: a moderate decrease in $/kWh output will make batteries quite attractive for many grid-connected homes. So "watch this space," I guess.