Tesla Powerwall: All Solar, All the Time

Tesla Energy Powerwall
Tesla Energy Powerwall mounted on the wall to the left

In case you missed it, one of our world’s great visionaries, Elon Musk, announced Tesla Energy last week, specifically the Tesla Powerwall.

What is it?

The sun only shines part of the day, making the energy generated by solar energy systems unavailable at night. With the Tesla Powerwall, your solar1 energy produced during the day is stored in the Powerwall batteries, and your home, factory, etc. To use during the night.

Land Mass Required to Power USA with Solar
Land Mass Required to Power Entire USA with Solar (Blue); Batteries for night (Red)

Elon said that the amount of physical space on the planet needed for solar panels, if we were to make all electricity in the US via solar panels, is much smaller than people imagine. (See the blue square. That’s it!) And most of that space would be existing roof tops.

The amount of physical space required to store the electricity generated during the daylight hours for use at night is the size of the red spot in the photo.

But, the most shocking think I heard him say was the cost of the Powerwall. A Powerwall than stores 10kWh of electricity is only $3,500. It mounts on the wall inside or outside of your home.

Naturally, we are exploring this to determine if, in this area, we would be able to go completely off the fossil fuel, nuclear reactor grid and get all of our energy from the sun. If we can not go completely off grid, to what extent would we require the grid? And remember, this would include our driving, as 2 of our cars are electric only. Our maximum solar system output on one day has been 68.1 kWh. I am unsure how much electricity we use at night, or post solar production for the day.

Our power bill dropped from $350 a month to $100 last month with the solar panels. It’s hard to make projections at this point because we were using heat until this month, in which we have been using air conditioning. We need more time to collect data. And, finally, we are using only about 50% of our available roof top space for solar panels.


  1. wind could be used, too