> you could build enough solar panels that solar output at 18:00 matches power demand

No you could not. For half the year the sun has set by 18:00.

You won't get 12% return if your panels generate electricity which is only paid between 18 and 19, because there is already overcapacity between 16:30 and 18.

They are super economical… which is why there’s a subsidy required for people to buy them?

It's not stupid if they are paid off by the people selling the coal and gas.

It's just a treasonous level of corruption.

Voters opting to be extorted like this would have been stupid.

More details please, do they have a website that explains their setup?

Are they a hoarder of old car batteries and the like?

What is their fire suppression setup like??? Granted I guess they could be doing pumped hydro storage lol

Does he have a saltwater aquarium, or any other hobby that can make use of it? If not, I can highly recommend that he get into it, if he's into that kind of overkill :)

My dad buys lead acids written off from storm damage to solar systems (The whole system gets replaced under insurance even if the batteries are just a bit worn) and then sells them to preppers in the middle of nowhere. For a while he had above 300KW/h of storage, basically completely off grid with few shutdowns. It was kind of nuts. His house did burn down, but it was arson.

That's ~8 used EV batteries. Each cost less than 10k, maybe 6-8k AUD.

If you know your way around high voltage DC, got a tractor and appropriate emulator - not exactly difficult or super expensive to pull off.

Granted it's pretty uncommon setup as grid batteries themselves are pretty cheap too and used EV battery is simply too large for home user, too much hassle, liability, etc to save like $2-3k.

At current battery project prices, matching Snowy 2.0’s roughly 350 GWh of energy storage capacity with Tesla Megapacks would cost around AUD $218 billion [0] and require Tesla’s entire global Megapack production capacity redirected to a single client for five years.

$15 billion is far more than Snowy 2.0 should have cost. But it remains substantially cheaper than any lithium-ion battery build for bulk storage. Storage on this scale is essential in a post-coal electricity grid, and batteries are not (yet) plausible substitutes for bulk storage.

[0] This assumes linear scaling. In reality, placing an order like this would grossly distort supply and demand on many levels. Thus the cost would ultimately be superlinear.

From Australlian ABC news...

The cost of the Snowy 2.0 pumped-hydro project is estimated to range from \(\$12\) billion to as high as \(\$42\) billion depending on the scope of costs included (such as direct construction, interest, and broader transmission). Originally announced in 2017 with a $2 billion price tag, the project has faced massive scale and logistical blowouts. The cost of the Snowy 2.0 pumped-hydro project is estimated to range from $12 billion to as high as $42 billion depending on the scope of costs included (such as direct construction, interest, and broader transmission).

That said , hydro systems have a LONG LIFESPAN - 100 YEARS ?

Batteries need to be replaced every X years.

So the ecomiomics of the comparisoan would need to be calculated ...

That was exactly the point of the project though - it was designed by the conservative side of politics in our country to try and crowd out investment in batteries and other renewables while taking enough time to build to keep coal plants operating longer in the meantime.

It didn't work at all for that though - we had a lot of private investment in large-scale batteries anyway, because the cost came down quickly just as most people (apart from the conservatives) expected. Then the other side of Government got in and put a subsidy scheme to get hundreds of thousands of home batteries installed, which has been multiple times better bang-for-buck than the Snowy 2.0 scheme, as well as taking far shorter a time. At the same time coal plants are shutting down as expected because they are increasingly unreliable given their old ages.

Snowy 2.0 be an expensive stranded asset basically, it will work and be somewhat useful but extremely uneconomical so basically relying on the cost being written off - if it had to recoup any investment then it couldn't run because it'd never be able to sell the power for high enough.

You can do similar math with building above ground oil storage tank capacity aaaaaand giving everyone free gas cans.

And you can get out every drop. And it’s always ready to go. Do need to cycle your inventory.

Fire departments probably wouldn’t be happy about it.

From elsewhere:

   this applies to NSW, South Australia and part of Queensland.

As for everybody in the same time zone .. they are all seeing the same sun angle at noon (more or less) and all sharing the same over supply of power from all the grid connected solar power rooftops and farms. It's free surplas power during that time frame.

There's too much available power then (curtailment/negative prices are fairly common now on sunny days), and not enough during the evenings, so it's an incentive for those who don't have/can't get batteries (e.g. renters) to shift their habits. It also can be spun as a cost-of-living action.

You might check the rates on Tibber as well. A lot of companies that offer a "free" usage period tend to just move the cost around. If you're comfortable taking the risks associated with a wholesale supplier, then you can likely save a ton of money without even changing your consumption habits.

During this past month with the heatwave, my electricity bill was only about €50 despite running airco all day most days. I have 6 solar panels on my roof for reference (was 3k installed I believe). If I was willing to turn off the A/C at night, I could have easily cut the bill in half since most of the billed usage was between 18-21:00.

https://www.budgetthuis.nl/energie/gratis-stroom

There's also the electricity transport costs. We're talking about the pure electricity cost here.

Well, sure, but that goes without saying?

I don't have smart washers, but I did build a smart ESP32-based [0] zigbee numerical display. Then I use Home Assistant to send the current electricity price to that display when the price changes, and send a notification to all users' phones when electricity is cheap (< 0.05€/kWh) or expensive (> 0.15€/kWh). This helps me plan my laundry and dish washing, which are the only energy intensive appliances I have. I also try to avoid cooking complex meals in the stove+oven.

[0] https://www.aliexpress.com/item/1005010546076391.html

Storing energy in hot water is common is sunny regions, for example Turkey.

Some large cold storage facilities in Germany are trying to optimize electric demand to use cheap peak day electricity. But they have to observe limitations in range of temperatures and capacity of cooling devices.

https://www.cleanenergywire.org/news/cold-storage-facilities...

" Compared to conventional cold storage systems, renewable energy-driven cold storage demonstrates a 10–35 % reduction in energy losses"

https://www.sciencedirect.com/science/article/abs/pii/S23521...

Many of us with solar already do this manually, we run the appliances once the sun is up. Even the hotwater heater is programmed to only heat during the middle of the game.

I've been daydreaming about the tank of water idea as well, but the amount of panels you would need on the roof would be crazy.

Or plug them into a UPS that charges when it's free but you can run them whenever.

Yeah totally, nice to be able to put the AC/heater on "for free". I even got a negative power bill once!

In my specific case, I barely use much power so home solar covers basically all of the usage, my bill is dominated by the daily charge, so the usage component is practically irrelevant to me.

Why shouldn't that be true practically every consumer home in the world?

Yes, grid scale deployments are cheaper, but I'm generally guessing a lot of the grid scale solar deployments do not price in the grid infrastructure adaptation costs, and I'm not even talking about grid storage.

Consumer rooftop solar is fundamentally democratic: it reduces reliance on centralized institutions for power delivery, Make society a lot more resilient in bad weather and other emergency situations, insulates everyday people from wild variations and petroleum and other consumable energy availability.

Combined with plug-in hybrid electric vehicles, it would enable electrification of 80 and 90% of daily driving without grid infrastructure costs.

You should still feel some guilt for the heat pollution your air conditioning causes for those outside your house, esp. in an urban area.

You need a battery to take advantage: then you may as well use a direct to market option like Amber. Which benefits grid stability too. 3 hrs without a battery is useless in Australia. As you generally use electricity for heating/cooling and need it longer than that esp. cooling.

My home is in London UK and is relatively small and efficient, but 8kWh may be higher than our peak demand ever over more than 20 years in this house...

It's not enough to charge a car fully.

Its a time honored Australian tradition to review new government programs and absolutely milk them dry.

The utilities don't really want to sell you the cheap solar. They'd rather write op-eds about how too much solar is flooding the grid and beg for more money to invest in the grid elements they can make money from.

The government is having to force them to reflect the abundance of cheap, clean energy at these times in at least one of their tariff offerings.

They can bend the rules slightly by adding other daily charges or limitations and upping the price at other times to reduce uptake and move us all slightly further from the global optimum but maximize their profits.

Before: 25c/kwh all day

After: 30c/kwh most of the day, 0c from 11-2

It's still worth it if you have a lot of load you can shift to the middle of the day (like a pool heater or battery), but for most 9-5 workers you just end up paying more at the times you're actually home.

Smart meters are free, most people already have one.

> Direct access to the wholesale market is probably not good for the lower end of the consumer segment

Not everything is for everyone. At no point did I feel like I was getting scammed as a customer. I was using them during the winter event.