Tesla Powerwall vs. AGL’s PowerLegato

So AGL have thrown their hat into the solar battery storage ring with the AUO PowerLegato manufactured by Taiwanese Solar and Electronic conglomerate, AU Optronics.

So how do they compare on specs?

a powerwall and a powerlegato

Tesla Powerwall Daily Cycle Model
AU$3,800 (wholesale price, not installed)
3.3 kW
single or 3 phase
no inverter included
no UPS features included
10 year Warranty
92% round-trip DC efficiency
350 – 450 volts
Operating Temp: -20°C to 43°C
1300 x 860 x 180mm
AGL/AUO PowerLegato
AU$9,990 fully installed on an existing DC solar system (updated 8 July)
3kW continuous, 4.5kW peak
single phase only
4.5kW PV Inverter included
UPS feature built in
unknown warranty
unknown round-trip DC efficiency
48 volts
Operating Temp: -20°C to 40°C

The key differences to note are that:

a) the powerlegato comes with a built in 4.5kW solar inverter – so you can plug your panels direct into the unit (although there is only 1 MPPT which will limit panel install options)

b) the powerlegato offers a UPS (Uninterruptable Power Supply) feature. Which should provide blackout protection, while the battery still has charge.

The upshot is that with all the extra hardware needed to achieve these 2 features, the AGL unit is likely to be expensive compared to a bare bones Powerwall installation.

AGL are banking on Aussies paying more for those features.

The magic price point in the solar market in Australia has always been about $7,000. If you can add a good brand of storage for around $7k, the units should fly off the shelves. AGL’s offering is likely to be closer to double this.

Also – please be aware that the AUO PowerLegato is not exclusive to AGL. Most solar installers can buy one from an Australian wholesaler and install it in your home. So it is worth getting multiple quotes if you really like the look of it.

UPDATE 8 July 2015: AGL have announced that they are selling the 7.2kWh Power Legato, fully installed into your existing solar system for $10,000. That’s a bloody good price for 7.2kWh with backup.

About Finn Peacock

I'm a Chartered Electrical Engineer, Solar and Energy Efficiency nut, dad, and founder of SolarQuotes.com.au. My last "real job" was working for the CSIRO in their renewable energy division.


  1. Battery storage technologies promise most hope for independence from utility companies, whether state or privately owned. These technologies are in their infancy. Musk & Co will make it happen. All power to Elontronics!~

  2. David Brien says

    Thank again for keeping the information flowing to the under-informed.
    Can you explain please what the difference on Voltage means? I take it this is output in DC.

    • Yes it is in Volts DC.

      The Tesla batteries (which are probably connected in series) have an output voltage that is similar to that of a solar panel array. This is good because it makes it compatible with your existing solar inverter.

      The PowerLegato’s batteries must be connected in parallel and output 48V DC which the internal inverter converts up to 240V AC.

      You could argue that low voltage DC is safer to have in your house than high voltage DC, but most solar owners have high voltage DC in their homes already!

  3. William Sharpe says

    Hold on, the powerwall explicitly has a DC to DC inverter that can plug directly in to your solar panels, which you called a DC charger in the “Cheap and cheerful” post.

    How is this different from the PV/Solar inverter mentioned here?

    • Yes – the Powerwall has a DC-DC converter which converts one DC Voltage to another DC voltage. This means it can charge direct from a solar panel array. But the powerwall needs an external inverter to convert the DC to 240V AC for your house to use.

      The PowerLegato has a built in inverter so it produces 240V from the battery with no additional hardware required.

  4. Robert Christie says

    Finn,,I would like some advise from you in fitting a Powerwall system to a normal home setup without solar Charging a Powerwall from the AGL off peak meter and avoiding a digital meter, with its higher kW ph pricing. Would the electric oven in the gas/electric stove draw too much current to run on a 10kwh PW?. I am considering this scheme so as to run the house thru a battery setup on off peak power pricing. I imagine the PW would need an inverter from the mains , and one back to the house for 240v?
    I expect other people wil be thinking along these lines

    Best Regards

    Rob Christie

    • Hi Rob,

      Tesla just announced the Powerwall has been upgraded to 5kW (7kW peak). This would handle a typical residential oven.

      Yes – you would need an extra inverter. All the analysis that I’ve seen is that installing a powerwall without solar, simply to arbitrage off peak would not pay for itself before the battery warrany expired.


  5. Hi Finn, just wanted to check, is the AGL option also lithium-ion?

  6. Finn,

    I have installed a 3kw solar panel and inverter/charger system with a 200ah 48v agm battery backup system.
    I use the system to provide 24hr power to my base load my fridge and freezer and lights.
    It is has a mains backup for when the battery falls below a preset figure.
    This was a starting system that cost $7,000.00 and I agree that an additional 2kw solar system and doubling of my batteries would complete the system at an additional cost of $4,000.00.
    My batteries are AGM and of course cannot be fully discharged like nicads but the Tesla wall power realistically will cost about $7,000.00 installed by the time you allow for the difference between the aussie dollar and the us dollar, transport and installation.
    Compare this to $3,300.00 for local agm batteries that can provide 5Kwh of power to a DOD of 25% that would see the batteries last at least 10 years.
    I suppose my point is, how about we wait until this technology is either superseded or the price comes down to match the capabilities of AGM batteries.

  7. You can also get decent deep cycle flooded lead batteries for much cheaper than AGM and, arguably, they would be good for five years or more if looked after. Six 100 Ah Australian built batteries would cost about $1400 and provide the same capacity as the 7 kWh Tesla or PowerLegato.

    Not to mention I can pick them up at any of my local auto stores.

    No one is going to pay so much money for lithium-ion batteries when it can be done cheaper and better with traditional flooded lead acid or AGM batteries at less than half the cost (not to mention far safer and without active or thermal cooling).

    • That’s right Ben, but my preference is AGM as I want maintenance free batteries so I can install and forget. I have had lead-acid batteries in the past but found I would not check them regularly enough and sometimes find them low on electrolyte which drastically shortened their life.

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