> TEOTWAWKI Blog: Tesla Powerwall



Tesla Powerwall

Image via Tesla.

Tesla Motors made big headlines this past week when they announced the Powerwall, a sleek solar/backup battery system and major aesthetic upgrade to banks of golf cart batteries daisy chained together.

Aside from the slim/sleek form factor, Powerwall is powered by the same state of the art lithium ion batteries that run Tesla's electric cars. I've heard rumor that these are just hundreds of 18650 batteries daisy chained together, but either way, li-ion are the best battery tech available today good for many more cycles than older technologies--more dependable and basically maintenance free, too. Laptops, smart phones and similar have been running on this tech for years now.

It's actually a pretty smart business move on Tesla's part, since current battery banks products are so crappy, hobbyist/pieced together. Powerwall lowers the barrier of entry to the average person--it's a self contained, plug and play unit, and pretty slick looking too...versus a big tangled mess of deep cycle batteries daisy chained together.

At $3,500 for 10 kw/h, it's not dirt cheap, but not out of this world expensive, either. And of course, it's only the battery--you'd need an inverter to connect in with the house and power things, and a source of electricity to charge it up. That could be grid power, solar (Tesla's intention), or some other off-grid source of electricity. I'd ballpark $10k-$15k total to be set up with panels and inverter...probably some government incentives to help ease that pain, too.

Realistically, 10kw/h is not enough to power the average American home. Small electronics, TVs and such would be no biggie, but throw in A/C, refrigerators, electric dryers and so on and you'd deplete your Powerwall pretty quickly. You can, however, daisy chain the units together for increased capacity. Tesla showed off a cabinet that would store 10 of the Powerwall battery banks - giving 100 kw/h capacity. These are more targeted towards businesses and utilities, but a well funded prepper with serious power needs could certainly do worse.

That said, with some careful selection of appliances, power conservation and build techniques, a survivalist retreat could of course be made much more efficient than the average American home...you don't need A/C to live, can dry clothes on a line, use propane or wood for cooking and heating needs.

The Powerwall may be a bit of a niche piece of technology, but it's pretty cool, too. Time will tell if the solar-electric vision for the future comes to fruition, with panels, Powerwalls and Tesla cars parked in garages across the company. Right now, the all important economics don't really make sense for the average household--but the market is certainly maturing, the technology becoming more user friendly and prices becoming ever more affordable.

Pretty cool time to live in and interesting technology to watch grow.


  1. The two big bugaboos about renewable energy (esp. PV) have been batteries and the inefficiency of solar panels. While a solar panel gives you 'something for nothing' in terms of energy from free sunlight, they only operate at, max., 20% efficiency. But thats better than 0%.

    Tesla's heading in the right direction, I think. The market for $200k cars with 100-mile ranges is far less than the market for $3500 batteries for off-grid and backup apps. If Tesla does this right, I can easily see it becoming far more profitable than their automotive division.

    1. I'm not sure where you got your numbers but their 70D will go 240 miles and their 85D will go 270 miles for $75k and $85k respectively. Factor in a hefty tax credit and that's not an awful deal.

      I think we can all agree the potential for the Powerwall is massive.

    2. AnonymousMay 04, 2015

      20% is questionable. The efficiency rate of modern panels is closer to 12% - 15% under optimal conditions. While it is better than nothing, panels have a L O N G way to go!

  2. AnonymousMay 03, 2015

    This announcement generated quite a bit of excitement in the solar-panel-owners circles I'm around. The utilities here have been fighting with solar customers, so more and more (even non-peppers) have been asking about battery options.

  3. riverriderMay 06, 2015

    it may one day soon go from a nice-to-have way to save money and become a necessity to keep the frozen food frozen. if the epa/obummer get their way there will be rolling blackouts as power companies struggle to keep up while closing down power plants. like third world does now, and some not so third world. that's a part of the "smart meter" they didn't tell you. well that, and a power surge thru it will burn your house down.