Solar Batteries On Special: Should You Trust Aldi To Power Your Home?

An Aldi supermarket in Adelaide.

Good old Aldi — the home of supermarket savings, shelves lined with classic grocery staples like milk, bread, cheese, and… wait… is that an entire solar-and-battery system on sale next to the dog food?

Aldi’s discounted offerings have allowed many Australians to keep the lights on through the cost-of-living crisis, but the multinational chain is now pledging to do so in more literal fashion. Getting a cut-price deal on dishwasher tablets is one thing, but is it a good idea to power your home with something fished out of a supermarket bargain bin?

Clean (Energy) Up On Aisle Five

Tempo Group has long supplied Aldi with cheap electronics, and is partnering with the German supermarket company to launch Aldi Solar: an “all-inclusive package from $7,999*” that includes 6.08kW of Altius rooftop solar panels, a 5kW hybrid inverter and a 5.1 kWh battery — all fully installed. Altius is a little-known brand in Australia that uses rebadged Chinese products.

The asterisk on that figure is because “prework may be required at an additional cost which may include but not limited to; installation of a fire-resistant panel on weatherboard homes at an additional cost of $385 inc GST.”

Aldi will do a remote assessment of your property, and full payment is required before an installer visits your home to do the job (contrary to our guidance of on-site inspections being best, as a number of key details can’t be confirmed without one).

It appears that Aldi Solar is selling its systems online, so you likely won’t be able to literally pluck one off a shelf in aisle 5, although SolarQuotes has reached out for confirmation on that.

You pay for what you get at the supermarket, and it’s always a good idea to check the expiry date before buying a heavily discounted tub of yogurt. With that in mind, SolarQuotes has taken a closer look at the fine print of this dirt-cheap solar-and-battery deal.

Solar Shrinkflation

Just as supermarkets these days sell bags of crisps filled with more air than chips, the Aldi solar package looks like it would fail to satisfy the energy hunger of most Australians. A 6.08kW rooftop solar panel array is not large by 2025 standards, and Aldi’s inclusion of a battery is even more of a reason for a larger solar panel array.

SolarQuotes’ resident fact checker Ronald Brakels explains: “the more solar you have the more able you are to charge your battery in winter or periods of lousy weather. It also helps stop you from starting to drain the battery in the late afternoon, potentially before the evening peak starts.”

Even more modestly sized is the 5.1 kWh battery itself, of which 4.6kWh will be usable. If you were to keep 1.6kWh reserved in case of blackouts (enough to run lights, refrigeration, and a TV for maybe a few hours) that leaves just 3kWh leftover for energy savings — which Ronald estimates might save 63c per night (flat rate) or 93c (time-of-use) per night.

Promising Sydney Sun In Melbourne

A case study from the Aldi Solar website.

One key detail to note is that Aldi is at this stage only launching this offer in Melbourne. Unhelpfully, case studies such as that of ‘Brandon’ splashed all over the Aldi Solar website are based on estimated savings in Sydney — where solar-and-battery systems are more financially lucrative. Ronald has checked Aldi’s receipts and wonders if the cashier might have swiped some of the items twice:

“The first thing to note is that ‘Brandon” uses around 2.5 times more than the Sydney residential average, which means the savings would be larger for him than most. Even then, if ‘Brandon’ saved $1,800 then he saved about 45c for every kWh generated, in a city where the average grid kWh on a flat tariff costs around 33c. Is there some kind of miracle that allowed ‘Brandon’ to magically save an extra 12 cents per kWh out of thin air? Yeah, there is. ‘Brandon’ is miraculously stupid. The only way it adds up is if he has a time-of-use tariff and an extremely high peak electricity consumption. In other words, it only works if ‘Brandon’ has gone out of his way to select an electricity plan that’s bad for his household.

“In Melbourne 6.08kW of north facing solar will generate around 8,143kWh. This is 10% less than Sydney, but what really hurts the return is Melbourne’s much lower electricity prices. You can get a flat tariff from AGL for 24c/kWh. If I enter a 24c electricity price and a Melbourne postcode into Aldi’s calculator followed by a ‘Brandon’-level 31kWh of daily electricity consumption, it estimates my annual electricity bill savings at $1,603 with a payback period of 5 years and 7 months. That’s a saving of around 19.7c per kWh of solar electricity generated. Not a miracle, but pretty good.

“Interestingly, if I pretend I am ‘Brandon’ and enter 33c electricity price, 31kWh daily consumption, and a Sydney postcode it gives an annual savings estimate of $2,347. That’s a saving of 26c per kWh of solar electricity generated. This is considerably less than the ‘potential’ $3,600 in savings they say ‘Brandon’ is on track for, so this reinforces that ‘Brandon’ must be an idiot.

“If you instead estimate the return by using our own Solar & Battery Calculator using 6kW of north-facing solar, a 5.1kWh battery, and extremely heavy-use ‘Brandon’-level 31kWh daily consumption on a flat-tariff, then you get the following savings of $2,248 in Sydney and $1,547 in Melbourne.”

What’s In The Box?

That picture on the box of supermarket frozen pizza might look delicious, but the actual experience of eating its contents can vary — and solar hardware can offer similar pitfalls. Aldi has only just launched its new deal in Melbourne, so the SolarQuotes team in Adelaide has not yet been able to get our hands on the hardware itself. Our in-house installer Anthony Bennett has nevertheless taken a look at the installation guide for the Altius inverter offered by Aldi and found it not totally to his taste:

“Reputable manufacturers like Sungrow tell electricians that a battery hybrid system must supply the downstream essential loads and simultaneously be able to force charge the battery using grid energy. This means an Altius 5kW hybrid could use between 42 and 46 amps depending on how you calculate the load; so their specification of a 63 amp supply is correct.

“While they’ve made the correct assumptions on the supply rating, the cable specifications fall short of what I’d like to see. Whoever cut-and-pasted this instruction manual needs a lesson in Australian electrical rules — we don’t use freedumb units like ‘American Wire Gauge’. If you take the specified sizes and uprate them to the nearest metric equivalent, they’re still undersized in my view.

“There are some relevant instructions on fitting forked lugs or possibly bootlace crimps for the main AC terminations. That’s good, but seeing as they specify undersized cables, I would be astounded if they supply the right parts for the 16mm² cable advisable in most cases.

“Using screw terminations and a plastic cover with one glad fitting means electricians should use a 4 core cable. The only way I can see them supplying 63 amps would be to use a 10mm² cable in special XLPE or rubber sheath. Standard PVC could struggle to withstand the heat but I doubt the price of these installations would include anything but bare bones.

“The manual asks that insulation tape be used to prevent short circuits, but rated insulation relies on thickness, so if you can stretch it thin, the tape will lose whatever rated value it might have. Electricians basically use tape to identify things, so these instructions specify decoration, not insulation.”

So, Should You Chuck Aldi Solar Into Your Trolley?

Aldi Solar customers will also get access to the company’s in-house energy management app.

Major retailers like Aldi getting into solar-and-batteries is a sign such products have gone mainstream. The upside is that big corporations can leverage economies of scale to deliver lower prices, but the downside is that customers tend not to get quite the same level of care or quality.

As a new offering, there’s not enough to go on to give a definitive verdict, but at this early stage there are concerns around the small size of the system, plus the quality of the hardware and install. The price is tempting, but the advertised savings are very optimistic indeed.

SolarQuotes founder Finn Peacock does however see the Aldi deal as potentially suitable for a particular scenario: “If well-installed and the hardware proves reliable, this could make sense for a retired couple with low usage. But I wouldn’t install one without a bypass switch as it looks like if the inverter fails, you lose your backup circuits.”

If you’re brave enough to give Aldi a try, please leave a review here to start building a picture of how customers are faring. Likewise, we’ve created review pages for the Altius solar panels, inverters and batteries used in the Aldi Solar package.

SolarQuotes reached out to Aldi for comment, but has not gotten a response at the time of writing.