Tesla's New Powerwall Battery - Q&A's

By Kristy Hoare on in New Solar Technology

Update 28/08/2017: Tesla Powerwall 2 is now being produced, but availability in New Zealand is still limited.  The original Tesla Powerwall described below is no longer in production.   Click here for Tesla Powerwall 2 specs.

Rongomai School was one of 130 winners of Vectors 'Future of Energy' competition. The competition was aimed at Auckland's most deserving families, schools and community groups. Over the next few months, the 130 Tesla Powerwalls will be installed.  Once they are installed, Vector will announce the second phase of installs.


The Tesla Powerwall is an amazing new product that's about to come on the market in a few months time.  It is not completely revolutionary in terms of technology, but it is revolutionary in terms of making solar power storage available to a lot more people.  I would compare it to the ipod, where before there was mp3 players - basically this product is just a lot better than what we had before, and cheaper!

Elon Musk gives an amazing presentation about the Tesla Powerwall, check out the clip below.

Extra Information:

The 7kW Powerwall is meant for daily cycles, for example, solar powered homes that want to store their solar power collected during the day and to be able to use their power at night.

The 10kW Powerwall is designed for backup applications, for example, this system will be a good option for homes located in areas that frequently experience black outs.

Multiple batteries can be used in one home, up to 90 kWh total for the 10 kWh battery and 63 kWh total for the 7 kWh battery.

I've started to answer a few questions New Zealanders have about the Tesla Powewall.  If you have any questions please write them in the comments field below and I will endevour to answer them.

Are there any available in New Zealand?

Vector are importing the first 100 units in January 2016.

Do you have to go off the grid with a Tesla Powerwall?

No, when you get battery storage installed you can use as much of the stored energy stored as you like or as much as you can, then the power you use will seemlessly change over to drawing power from the grid or possibily solar power if it is being produced at the time.

You can go off the grid if you like, but you would need to make sure you have enough Powerwalls stacked up to make sure you will have enough power for your energy demand. It would be advised that you trial the Powerwall system first before you go off the grid. The true test would be to make sure you have enough power to live on over the coldest, darkest few days of winter.  Also you'll need to consider if there will be occasions you'd like to have more power e.g. if you have relatives to stay over at Christmas - there will always be a maximum amount of power you can use if you go off the grid. You could give it a trial - you could get the amount of Powerwalls you think you'll need to match your energy demand while staying connected to the grid, and when you are comfortable you could then disconnect.

What is the price for Tesla Powerwall?

(2018 Update: Previous content in this section is now out of date.  Please refer to the battery comparison chart for an idea of pricing).

To compare prices for a solar power system and battery storage installed click here to go to our quote request form.

How is the tesla powerwall different from other batteries use for solar storage?

The big difference is that the batteries tesla are using are lithion-ion batteries.  The same type of batteries used in Tesla vehicles.  Traditionally lead-acid have been the most cost effective type of batteries used in New Zealand for solar power storage.

Lead-acid batteries are high maintenance, complicated to set-up, bulky, need ventilation and not pretty to look at.  The Tesla Powerwall is complete opposite.

How many cycles does the Powerwall 10kW pack last for?

One cycle a week for 10 years.

Is it just another toy for the rich?

Yes it kind of is. There is no subsidies for solar power and storage in New Zealand which keeps it away from people that it would benefit from it most. The Tesla Powerwall allows for cheap renewable energy that will be a big upfront cost, but will save the homeowner thousands of dollars over the years.

The good part is that the Powerwall will help smooth out the peak electricity demand curves. Those New Zealanders with one of these systems will have less demand for grid power in the mornings and in the evenings when there is peak demand. Less peak demand will mean the lines companies can relax a little, because when ever they put up their prices it usually to do with their costs for increasing capacity for peak demand.  So once there is a big enough up-take of solar battery storage in New Zealand, it will bring down the price of grid power for everyone.

Also, as Elon Musk points out in the video presentation, that the Powerwall will help people in remote areas that don't have access to power.  Tesla have brought the price for energy storage down quite significantly.  So for some people in remote areas who could not previously afford a small scale electricity generation system and have been going without, might now be able to afford one.

Will the Powerwall be able to connect with a solar power system that has micro-inverters?

With an Enphase micro-inverter system you are able to attached any generating source as long as it is made to comply to NZ electrical standards.

What is unknown at this point is how the system will be managed, so how it will balance the generation from the solar panels with the customers energy demand and send power to the grid?  The question remains; will the solar pv inverter be able to communicate with the Tesla Powerwall?  Many inverter companies have optional energy management systems, so the question will be whether the inverter will controll Tesla Powerwall or vice versa?

Enphase are bringing out their own lithium-ion battery storage system at the start of next year, therefore micro-inverter customers will definitely have battery storage options in the future.

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