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In Australia, a home battery boom has helped cut wholesale power prices

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Re: In Australia, a home battery boom has helped cut wholesale power prices

#81

Post by skew-aberration »

rswail wrote: post #35
Wacari wrote: post #9

so in other words, heavily subsidize another technology (introducing cost shifts onto non-adopters, typically poorer people) to try and solve operational problems directly caused by oversubsidizing rooftop solar (another regressive cost-shift and extremely inefficient cost allocation relative to tx-connected solar) by bringing down wholesale prices (already a minority of the utility bill). Fixed costs, the majority o…

Wholesale power is ~37% of the customer bills. The other costs are the "poles and wires" distribution network and the HV transmission network. The government is also building out the transmission network to various renewable energy zones, which has the added benefit of making the transmission network more resilient. With large coal plants, the network was only one interconnector failure from blacking out a state (as…

I think you could use more citations.

The South Australia blackout was not caused by coal or renewables or lack of interconnectors. If there had been zero interconnects (the local grid was self-sufficient) it wouldn't have happened! The primary cause of the extended blackout was simply a lack of readiness/contingency planning/compliance particularly at several large windfarms. See wiki article.

Coal is generally cheaper for baseload power like an aluminum smelter, even though solar is cheaper during the day. Firming with wind/battery is not yet competitive but is getting very close and is at the point where building new coal power plants is not viable. Refer to gencost report. However, replacing such a large load with brand new renewable capacity is almost certainly more expensive than simply continuing to burn coal, particularly when factoring in the grid upgrades required to make such a transition.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#82

Post by plantain »

skew-aberration wrote: post #50
plantain wrote: post #18

The program has so far spent $2.5bn, and installed 11GWh. That's just the cost of the subsidy (~30% discount), not the cost of what home owners tipped in. Utility scale batteries are now at ~$66m/GWh, or about ~$726m equivalent. It does not make sense for everyone to be doing a bespoke installation inside their own home. It is ridiculously inefficient. We are a society. We don't build our own roads, water, grid, scho…

I agree 100%, this is one of the most inequitable government policies I've ever seen in this country. The numbers are much worse than you make out. The program has spent more than 2.5bn (the projected figure) and we don't know yet how much. The subsidy was closer to 70% for a typical large battery install. The government's own gen cost report would have put grid storage 1.5x ahead on ROI. Note that figures like $66m/…

I've tried to be as charitable on both sides. As you note the real subsidy is higher, but the owner contributions are still high, and the projected cost of the program is now closer to 7.5Bn.

It's pure middle-class welfare.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#83

Post by dyauspitr »

toasty228 wrote: post #19
thelastgallon wrote: post #2

Use EVs as energy storage. Millions of EVs form an energy reservoir. 20% of solar is curtailed now and q lot more in future, instead charge EVs. Pay the EV owners because they are creating a storage layer with their capital and power prices go negative hundreds of millions of times every year. No need of home batteries.

When I looked into it it didn't make sense to use an EV as a solar battery, the chemistry isn't made for high cycle counts compared to regular home/solar batteries.

You looked wrong. These batteries can do 100,000 charge-discharge cycles while retaining 80% of their capacity.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#84

Post by skybrian »

plantain wrote: post #18

The program has so far spent $2.5bn, and installed 11GWh. That's just the cost of the subsidy (~30% discount), not the cost of what home owners tipped in. Utility scale batteries are now at ~$66m/GWh, or about ~$726m equivalent. It does not make sense for everyone to be doing a bespoke installation inside their own home. It is ridiculously inefficient. We are a society. We don't build our own roads, water, grid, scho…

It makes enough sense in rural areas for a Vermont power company to lease batteries to residential customers. They avoid having to do expensive upgrades that way:

https://electrek.co/2026/07/28/vermonts-largest-energy-sourc...

Re: In Australia, a home battery boom has helped cut wholesale power prices

#85

Post by bad_haircut72 »

toasty228 wrote: post #23
bad_haircut72 wrote: post #13

Earlier quoted context omitted.

surely its possible to invent a "plug in road" system, then cars could charge (at least on highways etc) even when driving. I had this thought ages back when EVs first came out, to tackle the problem of long charge times when doing cross country road trips.

On today's episode of "HNer's totally realistic and not deluded idea"...

https://en.wikipedia.org/wiki/List_of_trolleybus_systems_in_...

It already exists and works so, not that crazy

Re: In Australia, a home battery boom has helped cut wholesale power prices

#86

Post by pydry »

matt2000 wrote: post #72
plantain wrote: post #18

The program has so far spent $2.5bn, and installed 11GWh. That's just the cost of the subsidy (~30% discount), not the cost of what home owners tipped in. Utility scale batteries are now at ~$66m/GWh, or about ~$726m equivalent. It does not make sense for everyone to be doing a bespoke installation inside their own home. It is ridiculously inefficient. We are a society. We don't build our own roads, water, grid, scho…

Fair points, but you are glossing over important issues: 1. You are using the current point-in-time cost for batteries as compared to a subsidy spent over years while battery costs were dropping. 2. You do not include transmission upgrades and costs to distribute energy from centralized batteries. 3. You ignore the benefits and efficiencies of having generation and batteries distributed and close to the source of dem…

also ignoring that Australia is building snowy 2 which is the world's largest battery by far, due to be finished in 2027-2028.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#87

Post by danans »

collinmcnulty wrote: post #42
dataengineer56 wrote: post #31

Earlier quoted context omitted.

What does "LCOE" stand for?

Levelized cost of electricity. All the costs that go into producing from a given source (capex and opex) divided by the total power generated.

> All the costs that go into producing from a given source (capex and opex) divided by the total power generated

... total energy generated.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#88

Post by plantain »

boxed wrote: post #62
skew-aberration wrote: post #55

Earlier quoted context omitted.

Final numbers are not known yet. The Australian government's own 'Gencost' report put grid vs home based storage at 2x as efficient. In this subsidy program, the ratio of private to public money per a battery is about 1:2 (ie 70% subsidy). It was in my own case. Therefore, we would have had more battery storage if the government had just built grid storage.

It says the subsidy is 30%. You just said it's 70% and that it's 50% in the same sentence. Surely you can give one link to something that backs up anything you said.

The program is of course much more complex than can be fit in a HN comment, and it has evolved over time. The simplest answer is the government contributes $252/kWh. Approx. 4x the cost if the government funded a utility scale BESS - noting the installed cost of a home battery is 400-1200$/kWh depending on brand/options etc.

Re: In Australia, a home battery boom has helped cut wholesale power prices

#90

Post by skew-aberration »

boxed wrote: post #62
skew-aberration wrote: post #55

Earlier quoted context omitted.

Final numbers are not known yet. The Australian government's own 'Gencost' report put grid vs home based storage at 2x as efficient. In this subsidy program, the ratio of private to public money per a battery is about 1:2 (ie 70% subsidy). It was in my own case. Therefore, we would have had more battery storage if the government had just built grid storage.

It says the subsidy is 30%. You just said it's 70% and that it's 50% in the same sentence. Surely you can give one link to something that backs up anything you said.

Everyone in my office paid around 7.5-8.5k AUD for batteries around the 24k mark, so I know this to be the case. I could email you the invoice if you don't believe me xD

You can read up on the subsidy itself too - they basically set a cost per kwhr target based on the few bespoke batteries on the market, before it was flooded with cheaper Chinese options. Because it was based on capacity rather than a percentage discount, this caused the effective discount to be much higher than intended at the outset.

We don't know the final numbers yet - but government has reforecast for 7 billion for the program's duration, which includes a much smaller subsidy continuing until 2030. I expect it will be close to about 5B spent so far.

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