In Australia, a home battery boom has helped cut wholesale power prices • Hacker News Board

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

#261

Post by fragmede » Sat, Aug 15, 2026, 1:53 AM UTC

whatever1 wrote: post #255

imtringued wrote: post #223

Earlier quoted context omitted.

Think of the knapsack problem but you're trying to fill your knapsack while minimizing costs. You have a given amount of demand, you fill your knapsack using a simple greedy strategy. You pick the lowest bid, then you pick the next lowest bid and so on, until the knapsack is full. Now the question is, why is everyone paid as much as the most expensive bid that was needed to fill the order? Because those bidders could…

This is nice and fair only when you have infinitely many small producers. In reality you have two huge players who can cut production at will and set prices based on the least efficient small fish in the pond. Enjoy your free market

Who are the two players?

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

#262

Post by stubish » Sat, Aug 15, 2026, 2:26 AM UTC

skissane wrote: post #238

pnw wrote: post #45

Earlier quoted context omitted.

If you read the article, most of the decline in gas consumption in Australia is from changes in industrial usage. Residential demand is only down by 6% and part of that is likely due to the effective ban on gas in new residential construction which started in 2023 in Victoria. Prior to 2023 residential gas usage was increasing.

> Residential demand is only down by 6% and part of that is likely due to the effective ban on gas in new residential construction which started in 2023 in Victoria. Prior to 2023 residential gas usage was increasing. There's a lot of people who would get gas if only it were available. My house (in NSW), the gas main ends two streets away, they won't connect me unless I paid them some insane amount of money ($100K or…

With gas getting more and more expensive here in Victoria, and electricity prices plummeting and already free if you get a decent sized battery, the gas connection ban seems mostly pointless. Nobody will pay $300/year for the connection (+installation) so they can have the privilege of paying for their heating and cooking, and even without a battery you are still looking at 3-4 times the cost with gas heating vs. electric heating with a COP of 3-5. It may become legal, but nothing would change unless they also subsidize the gas providers to lay pipes and keep the existing ones working, because it just wouldn't be profitable to them otherwise. Energy retailers (resellers) already don't want the business, with a number of them electricity only and the rest just doing it as an incentive to attract customers to their electricity offers.

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

#263

Post by stubish » Sat, Aug 15, 2026, 2:33 AM UTC

ColdStream wrote: post #221

AnotherGoodName wrote: post #17

It started with a solar boom, many small home scale solar roofs popping up everywhere. Australia has a free trade agreement with much of the world, including China, and solar panels have literally dropped to 1/50th of the price they were in 1990 ($10/W to $0.2/W today). A shout out to the work that was done to establish dynamic grid pricing too. Anyway that caused power prices to reliably go negative during the day a…

It has hit so cheap that here in Victoria that as of 1st October there will be 3 hours of free electricity in the middle of the day. Capped at 24KW a day but that is still impressive. As such, we can load up the washer/dryer and just schedule them for an 11am start.

It has been available from two retailers for several months already. Pricing is such it doesn't make economic sense unless you have a battery due to higher peak and shoulder prices (So get a battery! Even with loan interest payments it pays for itself)

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

#264

Post by stubish » Sat, Aug 15, 2026, 2:35 AM UTC

wolvoleo wrote: post #231

AnotherGoodName wrote: post #17

It started with a solar boom, many small home scale solar roofs popping up everywhere. Australia has a free trade agreement with much of the world, including China, and solar panels have literally dropped to 1/50th of the price they were in 1990 ($10/W to $0.2/W today). A shout out to the work that was done to establish dynamic grid pricing too. Anyway that caused power prices to reliably go negative during the day a…

Free Trade is amazing when it works. But it doesn't in many cases. Even with those solar panels: China has put many western manufacturers out of business by selling them under cost price with government support. It's cool for the consumer but it's an artificial trick that actually reduces the free market viability. They did this with a reason. Either to raise prices later or to create a dependency. Even if you don't…

Selling under our cost price. Not selling under their cost price. China can destroy western manufactures even while making a profit.

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

#265

Post by stubish » Sat, Aug 15, 2026, 2:41 AM UTC

stanislavb wrote: post #198

AnotherGoodName wrote: post #17

It started with a solar boom, many small home scale solar roofs popping up everywhere. Australia has a free trade agreement with much of the world, including China, and solar panels have literally dropped to 1/50th of the price they were in 1990 ($10/W to $0.2/W today). A shout out to the work that was done to establish dynamic grid pricing too. Anyway that caused power prices to reliably go negative during the day a…

Another effect - although wholesale prices are falling for the energy itself - energy providers increased their daily "power grid use" fees. As a result, having electricity at home is still more expensive compared to before.

We have inflation. Everything is going up, except electricity.

Interestingly, one of the retailers offering free power already in Victoria gives a $1 kick pack if you use no power during the (rather long) peak period. So users with large enough batteries are paying just $0.30 a day connection fee and nothing else. Limits coming in will I think restrict free power to 25kWh/day, so smaller or energy efficient households.

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

#266

Post by stubish » Sat, Aug 15, 2026, 2:54 AM UTC

laurencerowe wrote: post #218

epistasis wrote: post #110

This is exactly what utility propaganda and PUC manipulation in the US has successfully stopped from happening. From NEM3 in California, to charging a high fixed fee for being on the grid in other areas of the country, utilities have manipulated rules at every step to prevent a future that has cheaper electricity for rate payers. They come up with rather fantastic propaganda about how ratepayers with solar are burden…

In California consumer electricity is high because of distribution costs stemming form wildfire risks from distribution in rural areas and sprawl into the wildland-urban interface where many people live as urban areas have historically blocked development. Wholesale generation costs are some of the lowest in the country. These costs of distortion vary very little based on how much you as an individual consume but the…

Interestingly, with the new free power periods in Australia, it is now better economically to not install solar panels and instead spend the cost saving on a larger battery. Solar has become so popular in my region that periods where the grid pays more than 0 for power when the sun is shining are a statistical anomaly. My solar panels will now never pay for themselves, pissing away their power to the grid for free, but my battery will pay for itself sooner.

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

#267

Post by stubish » Sat, Aug 15, 2026, 2:59 AM UTC

JuniperMesos wrote: post #213

wffurr wrote: post #175

Earlier quoted context omitted.

I thought it was the opposite; it's blindingly obvious that everyone should be getting rooftop solar. The only thing holding me back is the need to work with the condo association on a new roof first.

This is a really important reason why it's not actually obvious that everyone should be getting rooftop solar - not everyone lives in a situation where they can make arbitrary capital improvements to their roof, or even owns their own roof to begin with (I personally live in a rented apartment in a building where the roof space is shared among many tenants). That doesn't mean rooftop solar panels are necessarily a ba…

In Australia now, you don't actually want to install rooftop solar. You want to install batteries. No point getting solar when you can charge your battery for free. You just have to ensure it is sized for winter so you don't end up paying the much higher fees for power during non-free periods.

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

#268

Post by stubish » Sat, Aug 15, 2026, 3:10 AM UTC

collinmcnulty wrote: post #109

modo_mario wrote: post #106

Earlier quoted context omitted.

In the end you have to replace those panels and nobody in your country now produces them or has the incentive to start producing them unless they not only drop the subsidies but sell well over market value.

In 25 years, those panels will still be producing 80% of their starting value. Imagine what you can do with 25 years of energy independence.

It would be great if they performed that badly. If my panels drop below 87.5% in 30 years they get replaced under warranty for a second 30 years of use. These are even the cheap panels. Amazing how much better the tech is now.

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

#269

Post by pibaker » Sat, Aug 15, 2026, 3:16 AM UTC

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…

A government subsidized home improvement project is an easy political sale. It gets the homeowners on board, because they will see an immediate drop in energy costs, plus they also get to personally pocket the increased property values.

Versus spending money on utility scale buildouts, where the benefits will come at an undetermined later date, unceremoniously, when the utility company lowers prices. And even after that happens your political enemies will still wag finger at the price tag of your project and ask why don't you spend that somewhere else.

Inefficient and overly preferential towards homeowners? Sure. But better than a policy that will be dead by political reasons. It is what it is.

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

#270

Post by stubish » Sat, Aug 15, 2026, 3:18 AM UTC

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 was surprised there were no companies offering finance deals, such as loans to cover the out of pocket costs. An energy retailer could lock in a customer for 10 years to reasonable rates, make more money, and customer pays less. I suspect it was because the limiting factor was not cash, but the installer capacity. Solar installers have been working flatout, and even more customers would just push their prices up further.