6 Month Review Of The Very First Tesla Energy Powerwall Installation

JUL 28 2016 BY JAY COLE 33

About six month ago, Tesla began shipping its first Powerwall energy storage unitsl now the first long term review is in.

Tesla Powerwall Garage Installation

Tesla Powerwall Garage Installation

On launch, Tesla prioritized delivering the first Powerwall units into Australia, and the very first unit went to a chap by the name of Nick Pfitzner from Kellyville Ridge, which is a suburb of Sydney in New South Wales.  

(Read our coverage of that event from January here)

Now Mr. Pfitzner checks back in on his impressions of the system (and the 5 kW solar PV system he had installed at the same time) to ABC News – 702 Sydneywhich in this case stands for Australian Broadcasting Corporation.

“I have absolutely no regrets.  The battery performance is still what it was on day one, and we’ll be keeping an eye on that over the coming years…I’ll consider more panels and another battery in a few years.”

While setting up a solar array and Tesla Energy system certainly doesn’t come cheap, and the payback will take a very long time, Pfitzner says he still saves 90% on his daily energy bill as a result.  Down from $5-6/day to 59 cents.

The total cost of that Tesla Powerwall system (which originally came as a 7 kWh unit, now available only as a 6.4 kW unit) and the 5 kW solar PV system?  $16,000 ($12,000 USD) – after incentives via the Solar Bonus/Credit Scheme (that includes ESS), which if not renewed, expires/decreases this December.

New 6.4 kWh Tesla Powerwall Specs

New 6.4 kWh Tesla Powerwall Specs

Again, it isn’t all about the money, as the first Tesla Energy customer notes:

“It’s about eliminating waste … so I’ll say, ‘hey kids turn off the lights’…We run the dishwasher during the day and shift as much power use to the daytime so we’re using solar power.”

“But we haven’t sat there frozen, turned off the lights and sat in the dark with candles.  You still need to live.”

Pftizner says that on a sunny day, the Tesla Powerwall could be filled up by around 11AM, then any excess power heads back into the grid.  Conversely, when the power is used up or the sunlight is not optimal to get through the needs of the day, power is taken from the grid as required.  Over the first 6 months, about 75% of his usage has been self-generated/contained.

“People with solar power know about the benefits but the Powerwall takes it to a new level for me. When the sun goes down, I’ve still got peak power from the battery.”

Return on investment for grid-tied solar in Australia is around 3-4 years, while combining PV with an energy storage system, such as the Tesla Powerwall, can extend that payback time closer to 10 years.

Check out the full reveiw at ABC News, Hat tip to Dairob P!

Categories: ESS, Tesla

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33 Comments on "6 Month Review Of The Very First Tesla Energy Powerwall Installation"

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I would only buy a string of Powerwalls if I could connect them directly to a Tesla $500 100-amp home EVSE; to feed power at near-supercharger speeds to a Tesla vehicle in my own home.

Why would you need to charge your Model S/X that fast? Isn’t Level 2 charging fast enough for you? What advantage do you think you would gain by cycling rather expensive Powerwall batteries every day, just to charge your car faster? Isn’t the car going to sit there all night anyway?

If you’re someone who frequently takes long trips in the Model S/X and then turns around and makes another long trip the very next day, then it may indeed pay you to cycle multiple Powerwalls to charge your car faster. But this scenario will be very rare indeed for most drivers.

Even then, his scenario doesn’t make much sense. I assume, as a human, he sleeps. At 10kW you can recharge a 90 in ~10 hours even if it was completely dead. If that’s not fast enough, you could go with the 20kW dual chargers.
Plus, wouldn’t it make more sense to sell your electricity to the grid at peak rates and buy what you need to charge at night at off-peak rates?

Agreeing with your point – I’ve noticed, in discussions like this, a distinct tendency for people to believe that the bigger the EV battery, the higher the home charging rate needs to be.

Truth is, I could charge a Tesla Model ZZZ from my current Leaf EVSE (6.6kW) and get the same around-town capability after adjusting the charge time (generally upwards a bit) to match the efficiency ratio.

Venturing out of town? Charge overnight then drop in at the nearest Tesla Supercharger to top up.

An EV with a big battery like a Tesla has LESS need for fast home charging than a car with a small battery.

Just like gas car drivers don’t need to fill up with gas every day before doing a typical day of driving, if you have a big battery you don’t have to have a full battery every morning either.

So even if you don’t completely fill your battery on any given night, you will still have plenty of juice for typical daily driving. Then you can finish the fill the next night.

If you have a very small battery (iMiev?), then you might need a fast charge after work so that you can go out on the town in the evening. Because you don’t have that extra battery buffer.

Frankly, I suspect that most Tesla drivers could get away with 110 charging the majority of the time (unless they are trying to take advantage of cheap electric charging in specific times of night)

“Return on investment for grid-tied solar in Australia is around 3-4 years, while combining PV with an energy storage system, such as the Tesla Powerwall, can extend that payback time closer to 10 years.”

Doesn’t this reflect the economic case of the Powerwall?

If a grid tied solar is only 3-4 year pay pack, but it would take 10 years to break even on a powerwall, then it is a bad investment.

Of course, it is a good thing for grid balance. But at the end of the day, the ROIC is very poor.

Also, once that 10 year is up, your warranty on that powerwall is out as well. That is a concern for sure.

I say, forget about the Powerwall and keep the solar until there is incentives to justify the Powerwall.

I don’t really get it why would anyone want a liion pack if they have grid power. Maybe in some places you can’t buy 100% renewable power?

Liion packs shine in off-grid installations where you would compare the setup with the costs of running a grid power line to your property.

Because in the long run, generating the power and storing it for use in the night is cheaper, especially in sunny regions.
The homeowner in the article pays lesss than 60 Cents (probably Australian Cents) for electricity. These systems last for 20 years (at least), and apparently pay for themselves after 10 years. You can easily calculate, that in the second decade of ownership, the payback time has come, and at today’s prices from the article, the guy will save approx. 18.000 $. More, when considering that most energy company’s know only one direction for price adjustments, namely UP.

Right. When was the last time a power provider asked for a rate decrease? In some places even with inflation near zero they are asking for 4,5, even 9% increases in costs

“These systems last for 20 years (at least), and apparently pay for themselves after 10 years. You can easily calculate, that in the second decade of ownership, the payback time has come, and at today’s prices from the article, the guy will save approx. 18.000 $. More, when considering that most energy company’s know only one direction for price adjustments, namely UP.”

That is assuming that there are no degradation in capacity within that 20 years with daily cycling.. That is over 7,000 cycles (granted not deep 100% cycling).

Lastly, doesn’t netmetering with TOU pretty much eliminate the need for battery backup?

Also, the cost of capital for the first 10 years to break even is what? 50%? So, that pretty much wipes out at least 15 years of saving in that 20 year period. If you lose 30% of your capacity in that 20 years, you would barely breakeven in 20 years.

Now, the only time it makes sense if you have excessive solar generation and utility doesn’t provide you with net-metering, then it “might” makes financial sense.

What is the payback time on not installing the system and keeping the grid connection? Oh, wait a minute, there isn’t one and you will forever be tied to the whims and desires of an outside entity for something you can wholly own right now.

Sounds like he would have been better off getting a slightly bigger PV system, rather than the powerwall, as he seems to be net metered.


PV system is limited by your solar exposure and surface areas. So there really is only so much you can install – and that’s without looking at a budget.

Generally, I’d say install as much PV as you can, since you never know your energy needs in the future and net metering will pay back more quickly (and if net metering goes away, you’ll be ahead.)

But some people (like myself and my neighbors) have very little area that can be used for PV; we’d want to use it to move to market rate metering and give us a whole-house UPS for when a tree falls in the forest.

Currently economics of storage isn’t very good.

But with the explosive growth of solar and the utilities pushing peak TOU rates into the evening when the sun no longer shines, the case for storage gets better and better.

And the price of storage still has to get dramatically cheaper. The price of storage has to get under $300/kWh installed to start making financial sense in some markets and fall to $100/kWh installed to really take off.

Until then it only will sell in niche markets or as pilot projects.

$12,000 for a 5kW Solar PV system AND a Powerwall 7kWh battery storage!

That is so cheap.

Solarcity wants $20,000+ to put a 5kW Solar PV only (no battery). The tax credit I think only pushed up costs and favors Third Party Owned (TPO) solar – good for Solarcity but bad for homeowners.

Ya. I was thinking he same thing. No way it was that cheap. Even if he did it himself I can’t imagine it being that cheap.

Solar install costs are also going to vary wildly by import cost of the panels and local labor costs. You can’t pay Nevada install costs in California or New York panel prices in California (at least, you shouldn’t be…)

Some notes of note:
-Home backup power is not cheap and easily reliable with conventional methods. Not only does Powerwall help save on energy costs, but many people can also include the drastic downsizing or elimination of a generator as part of the savings.
-Central power reliable varies greatly from region to region. Powerwall can help improve power reliability and cleanliness significantly or completely.
-Grid tied solar only without battery backup is not allowed in many areas and is only practical up to a point. Some areas have reached or are close to reaching that point and are changing regulations accordingly. Of course responsible people shouldn’t wait for regulations to do the right thing.

Generators are surprisingly cheap…Remember for the current powerwall you need to purchase the inverter separately and have an electrician install everything…Some area require a grid worker verify the work prior to the unit being turned on…

The next issue is the power rates…I’ve lived at my home in SoCal for about three years…Seems every year there’s a drastic change to the pricing structure and change of peak to off-peak times with the off-peak hours ever shrinking…Look at NV, people paid for solar and the utility company yanked favorable net-metering terms retroactively…

The net metering change in Nevada was not retroactive. Retroactive means they pull up your past bills and say “under our new rate structure your bills last year would have totaled $1875 instead of $1275, so you owe us another $600”.

Sometimes utilities will “grandfather” certain classes of customers and allow them, and them alone, to keep existing rates. That would have been nice for people who bought (or leased) PV under the assumption that tariffs were set in stone. But it’s not really fair to everyone else and Nevada Power never promised to extend such preferential treatment.

Generators are also loud, need ventilation or they could and have killed people. You get what you pay for. I would prefer to pay more for cleaner solutions. Also, there is never a payback on such systems. Once installed a power generating system and battery storage system will pay for itself.

Additionally, battery storage can and will eliminate the electric power that is currently wasted. And I mean wasted. Power plants are always producing excess power to keep up with demand. When they can store that power, and use the batteries power to ramp up when the need arises the bottom line for those power companies will go down. Exciting times.

Grid-tied vs. Grid-defection. Tied is almost impossible to analyse without knowing lots of variables. The other translates easily, knowing just the grid cost for kwh.

-net metering
-time of use
-tiered rate bills
-demand charges
-fixed monthly charges

All are aspects of the “grid-tied” analysis that can swing the conclusion.

As already commented, you would be hard pressed to come out financially ahead where you have the option to sell a watt back to the grid (net metering). In Arizona and Nevada, where buyback rates plunged to 2-5 cents/kwh, using a Powerwall behind the meter may be a better plan. Those areas have the peak rates, demand charges and monthly “solar taxes” (Salt River, APS, NV Energy). That stuff is making grid-tied storage look better and better.

Ultimately, it is going to be exciting when PV battery gets out of control in the residential space, regardless of costing more than staying tied to a hostile, polluting utility. No one can model where roof-top owners will say “screw it” to all the rent-seeking.

As an American who just moved back from Sydney AU I can tell you the payback is going to be real different. Aussie peak rates in the Sydney area are around 32 cents KWH AUD much higher than anywhere in the US even after converting to USD. PV Has a much better subsidy from the Australian government than here. But like here it is not a given it will continue. The main thing that could drive sales of power walls here and there is the rate that the utility pays for your excess production. Initially in Australia it was pretty high but has now been reduced to the point that it makes no sense to make electricity greater than you will use during the day. I ran the numbers for my girl friends house and discovered that the cost of producing was greater than the buyback rate so it made no sense to buy more panels than daylight consumption but when I looked at a power wall I came up with about the same payback period of 7-10 years all depending on grid price increases. Like others have stated where it really shines is off grid where you would have… Read more »

Glad the owner is getting benefit from this system.

In NY State, we have a construct even more beneficial to homeowners: during the day we ‘sell’ electricity back to the utility at the same price we bought it for (that is, provided we eventually use all the electricity we sold them. I do not completely do this since I’m oversized, but lately I’ve been trying to use more electricity by driving more, and setting the thermostat lower in the summertime.

Electric car charging as mentioned over the midnight shift helps the utility since the load on central stations is increased beyond the dangerously low levels otherwise experienced.

The utility also benefits since the excess solar during the afternoon helps offset all the high airconditioner use (the compressor uses more electricity during the hot days since the compression ratio increases and the amperage goes up).

(Compression Ratio in cars is a misnomer – what is truly meant is ‘volumetric ratio’).

I’d be curious to see how pricing develops over time. If pricing drops precipitously enough, you could save more money buying a year from now than today. This may hold for many years in a row. For this reason, I expect these to be sold through solar installers, which can hide the price trend from users.

Of course, this same argument holds for solar panels as well.

Solar City is a kind of decentralized utility where you have a kind of alien superstructure sitting on top of your roof that actually belongs to someone else – namely Elon Musk. There are innumerable practical problems when you lease rather than own, such as what to do with Musk’s lease when you sell? Or, what to mdo if you decide to do a major remodel of the house that will impact the rooftop solar system ? What if you decide to replace your old worn out composition shingles with Spanish tiles ? And so on…. The solar leasing idea sucks. It’s like having a lien on your house for the next 35 years. It’s like having Aaron Rents own all your furniture for the next 30 plus years. It’s a terrible idea. I utterly despise the solar city business model and therefore have no sympathy for the upcoming merger plans. I also don’t like the idea of being forced to lease the gas tank in my own car forever from Renault as was the case with the Zoe EV when it first came out in Europe. When Renault finally wised up and dropped the battery lease requirement, sales of… Read more »

Leasing allows people with limited income to get solar on the house, and some of those people may not be able to afford it any other way. It is a better idea to buy, but loan rates may make leases more favorable, depending on the area, credit rating, and loan amount.

If your power is getting turned off for non payment these programs should be very appealing.

“When Renault finally wised up and dropped the battery lease requirement, sales of the car went through the roof.”

Simply not true. Sales are currently very strong, but I sell ZOEs and I would estimate that 99% have the battery lease (arguably the version with the battery was never meant to sell – it’s very expensive – and was just for publicity).

The UK government just yesterday were on the cusp of signing a deal with France’s EDF (power generator & distributor) to build a new nuclear power station at Hinkley Point in Somerset at a cost of £27b. This morning HMG unexpectedly postponed signing for a couple of months. Hinkley Point ‘C’ won’t be finished for at least 20 years (some say it never will) and the price that has been agreed for the cost of the electricity is fully twice what it currently is.

This is a very clear indication of where the cost of ‘base load’ electricity is going.

I am not a supporter of this idea and it would be interesting to calculate how much PV and storage could be bought for the same money and how well it would compare in terms of energy supply. One advantage would be that a PV & storage system could be well distributed across the UK removing the significant losses in transmitting energy across the grid from one location.

VERY roughly, a 3.2 GW nuke will produce 25 TWh per year. You need about 25 GW of PV to produce that much electricity in the UK. That’s $25 billion at an installed cost of $1/W (see below).


Storing an average day’s output (roughly 70 GWh) would add another $10b if done with cheap lithium batteries. Plus another $10b each decade. Pumped hydro could be cheaper.

Seasonality is the real killer. UK PV produces very little power for extended periods during winter. There’s no realistic way to store excess summer energy for use in the winter. As a result you can’t simply use PV+storage instead of nuclear. You have to combine PV with wind, hydro, efficiency measures, flexible demand an, at this point in time, natural gas.