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Quite simply put this is what they ask you to do. To the point that the Australian government will heavily subsidise (30%) home battery installation.

Remember Australia has over 10x the rollout of solar than china (per capita of course). It’s not hard to achieve this for any competent government. Bluntly China’s government is corrupt and inefficient (usa is even further behind china since their current government is also corrupt and inefficient).

This rollout of cheap solar in Australia is causing power prices during a global energy crisis and a datacenter build out to plummet.

And fwiw i don’t think Australia’s government is perfect. But it should set the bar to other nations of ‘what could be’. You could have falling power prices right now if you enabled a government to encourage what is currently by far the cheapest form of electricity (solar).

This is what I am doing. 42 kWh battery, 6 kW solar and fully electrified house, 2x EVs. I am able to charge cars at work and so in the depths of winter I am able to run the house by charging during the 3 hour window. There have been just a couple of cold (~2-4 degC) days when the battery was depleted 1-2 hours before the window starts.

As the weather warms and we get more solar exposure we will easily be in excess. We get a very small export rate with a bonus for no energy consumption during peak evening hours which can offset the fixed daily charge.

There are a lot of gotchas that you need to be aware of. 42 kWh is nominal capacity not the actual usable capacity. House load, max grid import and export capacity, max inverter capacity, AC or DC coupled panels, battery charging profile, battery temp are all factors in how much you can charge in the window. For example I have max 15 kW grid draw, with a 10 kW inverter that can charge the battery. I can put in max ~30 kWh into the battery, so I also run other loads in the house to use the other 5 kW capacity. If I go over 5 kW house load the battery charge is clipped to maintain grid import limit.

Forget 3hrs free. We lived in the tropics in Australia with a ~6kW system and often had negative quarterly invoices (i.e. got paid by our retailer) ... esp. in winter months. Aircon, pool, appliances all electric. At the very least the pool pump ran free all year round.

Edit: should add, that's straight solar no battery

The Australian grid presently curtails ~7-18% of production every single day between 11:00 and 14:00.

I believe that incentivizing people to acquire batteries is precisely the purpose of the policy. It's good for the grid for there to be a lot of storage at the edges. As I understand it, the 24kWh cap is subject to annual review, with it being reduced/the policy being soft phased out once curtailment is no longer necessary.

Just for reference our fully electric household (including cooking, water and aircon). Highest usage this month on a very hot day was 25kWh. (Disclaimer: I am not in Australia. Already cover most of it with roof solar. No battery yet)

Yes - the regulated offer is capped at 24 kWh per day but some retailers such as Globird and CovaU are offering plans which include up to 50 kWh per day of ‘free’ electricity. With a large enough battery and inverter you could just end up paying daily supply charges of $1.65-2.20 per day.

I pay about 38c per kilowatt plus $1.70 per day for the connection fee. So by that maths, you'd save 8×0.38=$3.04 per day. A 10kWh battery is in the ballpark of $4000. So it'll take about 4 years to break even. Then you'd just have to pay the connection fee, which seem to be increasing every year.

An ev charging at 7kw will consume 21 of the 24kWh. Now, if you don't drive massive distances every day then this might not be the best deal, but I can see how this might be worth it for someone commuting 200km a day for example. Taxi drivers, and the like will also probably benefit.

Does anywhere in the world let you have multiple electricity plans on the same meter at the same time?

I love being ripped off because I'm renting, so instead of having a direct relationship with my service providers, they are legally allowed to sign binding contracts with the building manager who I'm sure in no shape way or form receives a kick-back.

So I'm stuck with an energy provider that is too incompetent to figure out how to bill me correctly, but puts a markup on what I'd pay as a home owner, and I don't even get the NBN despite having fibre to the premises!

No IPv6, no gigabit Internet, no free solar electricity.

> I'd love to see them on snowy 2 today.

I can only imagine the comment warnings on that segment considering that, sadly, John Clarke passed away nine years ago.

> 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.

If you build enough solar that the output at 18:00 matches the demand, it will not have the same ROI as if you are using batteries.

    > If batteries have a solid 9% return on investment, but solar panels have an even better 12% return on investment, panels will outpace batteries even though the batteries are a decent investment.

EDIT

I forgot to say: I like your idea of intraday arbitrage using batteries! It is a very cool idea. Surely, this could be well modeled to know your expected ROI before investment/build-out.

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

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

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

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.

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 :)

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.

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

It wasn’t $40-50 billion. It was estimated to cost $116-$600 billion to build 7 nuclear reactors https://smartenergy.org.au/nuclear-fallout-116-600-billion-t...

I think the likely cost would have been hundreds of billions considering Australia does not have a nuclear energy generation industry. It currently has a very small nuclear workforce as it only has a small nuclear medical reactor on the outskirts of Sydney.

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.

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.

The submarines will be in port so much of the time, we may as well hook up their nukes to power the grid.

To check I understand you: the smaller tank with heatpump would consume less energy outside the time window in which energy is free than the large tank with resistive heating, but has a higher capital cost which would outweigh the amount saved on energy?

If that's right, it's not obvious to me that building a suitably sized solar panel is environmentally worse than building a heat pump.

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 surplus 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.

I was trying to understand how to do this, and I formed the opinion that most of the battery providers don’t really allow the degree of ‘on/off’ or ‘charge/discharge’ customisation as might be necessary to make this work? Or was I fooled by the packaged products that are aiming to turn me and my battery and panels into a residential power plant at the whim of the energy company?

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...

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

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.

It applies in Victoria as well.

Victoria deregulated its market before NSW/SA/Qld.

All of the eastern states (SA/QLD/NSW/VIC/Tas) are part of a single market, with interconnects and wholesale prices set every 5 minutes.

Victoria has its own "default offer" and regulator of the retail market, which is also offering similar "free power" hours.

WA could be part of the NEM with some HVDC across the Nullabor, not sure if it would be economically worthwhile though.

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?

Yes, that's also being done. A critique I have seen is that this is empowering the rich to get richer. Renters are less likely to be able to adopt these strategies.

The Australian scientific body, the CSIRO, did an extensive report on the full life costs of various energy strategies and concluded that nuclear made little to no economic sense in Australia.

Perhaps had they used a napkin they would have agreed with you.

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.

Co-located PV/BESS or Wind/BESS is the best grid solution anyway. The REZs with transmission infrastructure (subsidized by government) will also add to the return.

The good thing is that even with over a decade of conservative government trying to kill it, renewables are now commercially the only choice for Australia and we will benefit from the rapid advances in storage as well.

Grid level plants are starting to also incorporate synthetic condensers and other FCAS services to make our grid more resilient and reliable, even as our clapped out coal plants move closer to shut down.

What makes large scale solar no longer profitable? Distribution costs have outpaced the efficiency gains of the large scale installation?

> It kind of sucks for the investors that adopted green tech

In the US, these people are known as speculators riding on government subsidy or grant, often shadily awarded - and anyone who couldn’t see consumer panel and consumer power-storage tech hooting its inflection point simply didn’t have a good grasp on the technology.

All important factors for investors.

That's the theory. Others in this thread are reporting the reality.

In practice, any profit-making enterprise will not want to miss out on the income they were previously getting, so will find other times and charges to load it onto. Also, they know some people will specifically choose an energy plan that seems to give them something free, so it's easy to take advantage by increasing the prices they pay less attention to.

> 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.

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.

Impolite.

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.

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.

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.