# Thread: Tesla energy, what is its true potential?

1. ## Tesla energy, what is its true potential?

Has anybody here done the math of determining the potential of the use of the Powerwall product by Tesla corporation? Let's say you want a self sustaining home run totally off of solar energy stored in the Tesla Powerwall installed into a small house where you want to have energy available for cooking food, coffee, powering a computer and keeping the house warm throughout the whole year, how would that be technically solved using the Tesla Powerwall, how many solar panels do you need and of what exact type and how many Powerwall batteries do you need to store the energy? How much money would leave your pockets to get there and how reliable would the solution be? Can the Tesla Powerwall get us off the grid?

According to this article you get ~3 hours at 2 kW per 10 kWh battery when considering the energy loss due to the DC/AC conversion (each having a weight of 100 kg), that's not so much. You can however then combine up to 9 of these for a total of 90 kWh. That would give you 27 hours at 2 kW, which should get you off the grid. That will cost you 3500 USD * 9 = 31 500 USD. That 900 kg investment will make you able to get off the grid for 10 years in case you also can afford the solar panels for it. The question is then what the solar panels cost that would utilize the capacity of the 9 pieces of 10 kWh Powerwall batteries?!

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3. ## Re: Tesla energy, what is its true potential?

It's good that you are looking into this, but imo anything requiring battery storage is not a solution since batteries are very hazardous and end-up in land fills.

For the kind of money you are looking at, you could probably hire an engineer that's already done free energy experimentation and have him/her build a WITTS device that would not require a large number of batteries for storage.

4. ## Re: Tesla energy, what is its true potential?

I'll maybe write some more later, but a few points:

- One option is to use gas for heating and hot water. Once you eliminate heating, you need far less electricity.
- One of the powerwall units is enough for one person if basic efficiency measures are enacted and you don't use it for heating. Two units would be more than enough.
- I thought I read that the powerwall home-system was 7 kWh so I'll do the maths on that one:

7 kWh battery, therefore need 7 KWh of energy to charge each day (assuming it gets fully drained between charges).
In Victoria, Australia, can expect an efficiency of about 3.5 kWh of energy generated per day, per kW of solar panels installed (3.5 kWh/kW).
Therefore you would need a 2 kW solar panel installation to get the 7 kWh needed to charge your battery, ignoring seasonal variation and energy losses during charging (probably ~5%).

I am using efficiency values from http://pvoutput.org/ladder.jsp?p=4&r...c=1&o=e&d=desc without checking the accuracy. Looks like in Sweden maybe 2.5 kWh/kw might be a more realistic efficiency, so then you'd need 2.8 kW of solar panels, but please do an internet search to check.

Since solar panels are so cheap these days, most people install 4 kW systems or larger, more than enough to charge the powerwall, even in cloudy locations. And remember to choose your inverter size carefully, inverters don't operate efficiently if they are over-sized.

edit: I forgot to mention that while charging your battery during the day, you of course still need some energy available for use, so you need some extra panels for that.

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6. ## Re: Tesla energy, what is its true potential?

Posted by Oouthere (here)
It's good that you are looking into this, but imo anything requiring battery storage is not a solution since batteries are very hazardous and end-up in land fills.

For the kind of money you are looking at, you could probably hire an engineer that's already done free energy experimentation and have him/her build a WITTS device that would not require a large number of batteries for storage.
The point of the Tesla article is that with the new battery technology you do not require a large bank of batteries. The new batteries are in production now, but i think i will wait for the price to come down.

http://www.theecologist.org/News/new...ear_power.html

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