Power House from MS Battery



The huge battery of a Tesla Model S could work as a perfect power source for your household.


Imagine using photovoltaic during day time: charging your Tesla, supplying the household with lot of electricity. In the evening  your PV system doesn’t generate power any more. But instead of buying electric power it would be perfect to use some kW from your recently charged Tesla 85kW battery.

Mitsubishi and other companies are supporting a system like this (keywords: smart grid, bidirectional charging). This system is even more interesting regarding a car with a huge battery like the Model S – your additional energy consumption of the Tesla battery is probably less than 5%.


Moderator: This is well beyond a software update, as a major redesign of the charging/battery electronics is required. That doesn’t mean Tesla couldn’t implement such a feature on future vehicles!

A new wall-charger connection would also need to be designed to flow the power in both directions and protect both the house electrical system as well as the vehicles.



Category: Tags: entered 7-Dec-2014


If you want to go off grid using PV just invest in the batteries that are designed for this.  It would add lots of cost to the car and for those folks who haven't invested in PV power (I have and love it) I'm confident that they don't want to pay for that function.


Furthermore, you'd still have to install a breaker box and switch to make sure you're not sending power back into the electrical lines.  I have a stand alone generator (gas powered) that I can do what you are asking and it's a lot cheaper than having my car, which I'd want to have power to drive in the morning, be my off grid power supply.
There are lots of problems and details to be worked out but this could be a major element in the effort to move away from fossil fuels by enabling the storage of intermittent PV and wind energy for later use on cloudy or calm days.
Tesla already sells a battery pack based on the packs used in their cars as a standalone house battery for the purpose of whole-house backup power, through their sister company Solar City. So certainly it is technically feasible.

Musk has said that it is best used as a backup power source, not as a source of power every day. He said something like people would have to be crazy to charge and discharge the battery everyday to save on electricity since the value lost in early degradation of the expensive battery would be much greater than the cost of the electricity saved. Plus, you'd have to oversize your PV system, which is quite expensive.

So, the above suggestion as backup power for the house during power failures is a good idea and feasible, but probably not for daily use.
Emergency power from the car, as well as a utility power inverter, makes a lot of sense. If the cycle life of the batteries improves significantly in the future, then we can talk about daily power storage.
I wonder what the effect on the life of the battery pack would be if it were to be used for this purpose? Then again, my prospective is probably skewed since I already have an automatic backup generator.