Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
×
Power Australia

Australians Could Be Charged For Exporting Energy From Rooftop Solar Panels To the Grid (theguardian.com) 210

An anonymous reader quotes a report from The Guardian: Australian households with rooftop solar panels could be charged for exporting electricity into the power grid at times when it is not needed under proposed changes to the national electricity market. The recommendation is included in a draft deliberation by the Australian Energy Market Commission that is designed to prevent "traffic jams" of electricity at sunny times that could destabilize the network.

The commission, which makes the rules for the electricity system, said the change was necessary to allow more household solar systems and batteries to be connected to the grid and make the system fairer for all electricity users. Benn Barr, the commission's chief executive, said it was expected an average solar household with a system of between 4 and 6 kilowatts would still save about $900 a year on power bills after the change, about $70 less than currently. He said it would reduce bills for the 80% of households who do not have solar as they would no longer have to pay for solar export services they were not using.

This discussion has been archived. No new comments can be posted.

Australians Could Be Charged For Exporting Energy From Rooftop Solar Panels To the Grid

Comments Filter:
  • by ian_mackereth ( 889101 ) * on Thursday March 25, 2021 @07:07PM (#61199316) Journal

    Yes, we are approaching a problem here in Oz. In Autumn and Spring, most cities still have plentiful sunshine, but the home air-conditioning load is much reduced, making many more MW available to the grid. Since the only method to regulate grid frequency is big spinning power plants, we have a problem when we don't need their power output.

    But there are better solutions, surely?

    Subsidise batteries, so more of the daylight solar power goes into providing night-time power, keeping households more autonomous.

    Change the grid regulators to large-scale inverters, probably associated with large scale wind or solar farms.

    • Re: (Score:3, Interesting)

      by Ostracus ( 1354233 )

      Didn't Tesla put some batteries down there? Anyway that's where smart meters are suppose to come into play where one can control connecting and disconnecting a customer (off grid they're producing too much power, remember).

      • by bug_hunter ( 32923 ) on Thursday March 25, 2021 @07:22PM (#61199360)

        My understanding of the big Tesla battery installation was that it's primary purpose was smoothing out power transmission from interstate. Not necessarily large enough to grab massive amounts of excess power and feed it back during off time.

        It is more efficient (as this fee is meant to encourage) for individual households to store their own excess power and use it up without transmitting over the grid.

        But I do share the opinion of the OP, I'm not fond of the issolated solution of adding fees to green households to help out energy companies.

        • My understanding of the big Tesla battery installation was that it's primary purpose was smoothing out power transmission from interstate. Not necessarily large enough to grab massive amounts of excess power and feed it back during off time.

          You're 12% right. From the original 100MWh battery supply some ~12MWh was dedicated to FCAS (Frequency Control and Ancillary Services) and the other 90MWh for storing energy and selling it back when the price is right.
          The reason you may hear the ratio reversed is time. The battery provides 70MW of FCAS capacity for a total duration of 10min when needed, and 30MW of steady power for 3hours.

          These are split duties. I.e. when electricity is expensive it'll sell its 90MWh capacity but leave the amount reserved f

      • Yes, but the bit Tesla battery is pugged into the wholesale layer of the network. Not at the street level where the problem is located. Solar power can't be shipped back up the grid, it must be consumed by your neighbours.

        I have no sympathy for the network operators. This is an entirely foreseeable problem, that they should have been trying to solve for the last decade.

        • power has been too expensive for too long
        • people install solar to cut costs
        • power network threatens solar users, or raises prices elsewhere
      • by trawg ( 308495 )

        The Australian energy operator does have the power already to disconnect rooftop solar generators from the grid, and they have used it already. I don't know the technical details but it seems like a relatively low-tech, almost last ditch measure to ensure grid stability.

        The 'smart grid' coupled with batteries and smart meters and stuff will, I reckon, solve this problem pretty neatly. When there's a surplus of power and the spot price in a local region is low as a result, operators can store the power and w

    • by rmdingler ( 1955220 ) on Thursday March 25, 2021 @07:18PM (#61199348) Journal

      It doesn't even have to be batteries.

      Molten salt, flywheels, and pumped storage [mpoweruk.com] are but a few great ideas.

      • Good ideas but who pays for these investments? Challenge building the optimal storage vs power gen. Ideally Power Cos have more scale but the solar owners benefit too. Predicting optimal levels will be a challenge. Some kind of compromise. And new biz opportunities. Storing power. Re: Knee-jerk easy answer (+1) rmdingler 9 minutes ago It doesn't even have to be batteries. Molten salt, flywheels, and pumped storage are but a few great ideas.
      • by hoofie ( 201045 )

        Pumped storage won't work in the central and Western parts of Australia which are relatively flat and often have little water.

        • by Immerman ( 2627577 ) on Thursday March 25, 2021 @08:07PM (#61199486)

          You still have stacked storage, where a big multi-boom electric crane stacks giant concrete "legos", building a tower with excess energy, and flattening it out again when the energy is needed. I don't know of anyone who's actually built such a thing yet, but the numbers look promising.

          • Trying to imagine what that would look like, for maximum stability over a potentially long period of time, and I accidentally came across another theory as to the builders of the pyramids. If they weren't filled with rooms and dead people, of course.
          • Re: (Score:3, Informative)

            by comodoro ( 4850881 )

            There is a demonstration plant in Switzerland:

            https://qz.com/1355672/stacking-concrete-blocks-is-a-surprisingly-efficient-way-to-store-energy/

            The costs seem to be relatively low, but not the lowest:

            it can bring costs down to about $150 per kWh. That means it can’t fill the needs of the third category of energy-storage use; to do that, costs would have to be closer to $10 per kWh [...] the current dominant battery technology, could fall to about $100 per kWh

      • by AmiMoJo ( 196126 )

        They should encourage people to use the energy when it is available. Smart chargers for cars, industry that can take advantage of low prices.

    • by rednip ( 186217 )
      The electric grid is a market with now with many suppliers, they need a way to encourage suppliers to temporarily store electricity to sell later that day (night). I see it as a stabilization force on the grid, with people unwilling or unable to vary power will 'peak out' with the grid floating about 95% for a transformer/circuit. In some places it will seem like an upgrade.
      • by dgatwood ( 11270 ) on Thursday March 25, 2021 @07:46PM (#61199416) Homepage Journal

        The electric grid is a market with now with many suppliers, they need a way to encourage suppliers to temporarily store electricity to sell later that day (night).

        Unfortunately, this won't do that. They'll just curtail the output of solar to match demand.

        The cost of storage compared with what you get back makes small-scale storage largely uneconomical. A PowerWall 2, for example, is rated for 37.8 MWh and costs $6,500. That's a whopping 18 cents per kWh. So unless you can make more than that during low-solar hours (many of which are off-peak), it doesn't make sense to store it.

        So as a consumer, unless your median power prices are always at or near 18 cents per kWh (e.g. California, Australia), investing in storage is unlikely to be a smart investment unless you are doing so solely for backup purposes (and even then, a whole-home generator is likely to be cheaper, last longer, and be more useful under a wider range of circumstances).

        But the bigger problem is that if you as an individual can bring in anywhere close to that much money, it makes financial sense for the grid operator to store power, too. And because they can do it way more efficiently at scale, as soon as they start doing that, the on-peak energy prices will fall, and it won't make sense anymore for individuals to do it. The grid operator and large power plants and similar are always going to be in a better position than you.

        I see it as a stabilization force on the grid, with people unwilling or unable to vary power will 'peak out' with the grid floating about 95% for a transformer/circuit. In some places it will seem like an upgrade.

        More than likely, the people who can curtail will curtail, and the people who can't will end up not paying the fee because of everybody else curtailing, and the people who win will be the people with older solar systems that can't curtail, because they'll be selling everything they can, and the folks who can curtail will be selling much less than one might otherwise assume.

        But I might be being too cynical here.

        • by ahodgson ( 74077 )

          The Powerall specs I see say 13.5 kwH. So it's more like $480 per kwH, not 18 cents. But theoretically you could sell the power from it thousands of times. In fact at max efficiency you could make it only cost you about 10 cents per kwH you resell before the warranty expires. Which is still at least 3 or times as much as wholesale power should cost but hey, you can feel good about giving the money to Elon.

          • by dgatwood ( 11270 ) on Thursday March 25, 2021 @09:04PM (#61199632) Homepage Journal

            The Powerall specs I see say 13.5 kwH. So it's more like $480 per kwH, not 18 cents. But theoretically you could sell the power from it thousands of times.

            You're looking at capacity. I'm talking about rated life. The rated lifetime delivery is 37.8 MWh. That's counting all of the thousands of charge cycles.

            • by dgatwood ( 11270 )

              And just to clarify, their warranty is only year-based and unlimited if you're using it for home backup purposes, not arbitrage. As soon as you start playing that game, your warranty becomes based on power delivered, not years.

      • Yes, but. That storage has to be installed on each street. We're talking about the residential power grids being overloaded. The power grid doesn't have a way to export power from your street.

        • Yes it has. It is called a cable. Or copper wire.

          • Specifically in Oz, not so much. The copper is overloaded, in affluent suburbs on a sunny day you can see line voltage of 270V compared with 240V nominal, as everybody's solar tries to export their power.

            • The inverters not be producing overvoltage. That's an instant disqualifier. They should be disconnecting themselves if they detect that the voltage is above spec just for self-protection. Any inverter willing to produce overvoltage should not be permitted to connect to the grid at all.

              When the first grid-tie inverter was made it famously shut itself off because the power on the line was out of spec... the spec provided by the power company. They couldn't themselves actually meet it.

          • The grid is built to push power from high voltage lines, to substations, to street level transformers, to the house. Trying to push solar into that street level transformer will not export anything back to the high voltage line.

    • by rtb61 ( 674572 )

      But, but, but, corruption, unlimited profits, what are you some kind of communist.

      Note the difference the way the little guy is treated in a corrupt government, compared to the corporations that control government.

      Talk about the ultimate in profits. The privatised grid operator charges you for the electricity you produce and then sells it with the ultimate in markup. I am not sure what the percentage increase in profits, when you turn a negative value into a full markup profit margin, like you generated t

      • Your ability to be so completely ignorant of even the most basic of science or physics, while constantly spouting off nonsensical bullshit about "corporations" is astounding.

        Here's an idea so you can START to understand the concept of the problem in a very basic way. Grab whatever you have laying around that runs on batteries. Pop the batteries out and instead hook the battery terminals to a wire and plug it into the wall. You'll see what too much electricity does. (Too high of voltage). But - don't do t

    • You're completely right. They're being lazy with a wash-our-hands approach to throwing the consumer to the wolves.

      One idea is use ripple-control to signal when not desiring excess and have the inverters in an area back off. The PV panels themselves don't explode if unloaded.

      • Heck, my first thought was solar-heated jacuzzi. Just tell me when you don't want my power, I'll be happy to do something else with it. Don't effing charge me for the privilege of letting you take it off my hands.

        • by sd4f ( 1891894 )

          My thinking is the same way. Surely if you're going to have to pay to send it out, it would be more cost effective to have a load bank and generate heat, be it into air, or make some more hot water for yourself.

          However, where this gets unstuck is that Australia, despite proclaiming for itself to be highly educated, it's incredibly highly regulated, and tinkering with this stuff is extremely prohibited unless the person is properly licensed. This means, if you can find a properly licensed electrician who can

    • fire up the bitcoin miners maybe.

    • But that option will never come about. I will build a bloody big air cooled heating element (Resistor) if I am paid. Technically pumping water would be the next bet thing. Australia having no steel smelters was a poor decision.
    • > Subsidise batteries, so more of the daylight solar power goes into providing night-time power, keeping households more autonomous.

      But how does that help the utility make more money? Sounds like more work for less profit when they can instead just slap a bullshit fee on customers who can't do much about it without splashing enough money to go completely off grid permanently. You're never going to be a Captain of Industry with that kind of thinking!

    • Next thing you know, you'll need a loicense to collect sunshoine.
      • by sd4f ( 1891894 )
        Don't laugh, this is Australia we're talking about. If government feels that there's a buck in it for them, they'll do that.
  • Buffer-free net metering is a bad idea once solar penetration exceeds a certain point. Add batteries, smart charging algorithms, and selling back in the evening duck-curve (or self-consuming) works so much more effectively and allows at least 3x the PV capacity with no utility downside.

    • All the downside goes back to the homeowner in terms of having to pay for the battery.

      But "solar panel prices are at parity or even below the cost of other generating sources" the evangelists say. That's what we call a lie of omission.

      A solar generating installation is cheaper than a thermal generating station, often by a lot. But a solar-reliant grid is not cheaper than a thermal-reliant grid. By a lot.

      Solar, wind, and all these other sources are basically dumping of electrons onto the grid. They're the ch

      • No, fossil fuels cost 100x more than renewables. They just aren't affordable.

        See, I can spout unsubstantiated bullshit too!

        If you want anyone to take you seriously, cite your sources and show your math. Otherwise we can just dismiss the dumb shit you're making up.

      • by jezwel ( 2451108 )
        Fossil fuels have been free-riding for centuries with carbon emissions and the near astronomical cost to remediate global warming. Cheap residential battery installations would kickstart some major changes, though if this does go through the cost of residential battery becomes a lot easier to justify.
        • Residential batteries aren't cheap. The ones that are top out at maybe 10 kW continuous power. That's an AC unit and half an electric or induction cooktop.

          200 amp service x 240 v is more than 40 kW peak. If you're cooking a big meal, you might start to brush up against 12 kW or even 15 kW depending on time of year and heating/cooling reqs.

          I haven't been able to find an off-the-shelf residential inverter/battery combo that could do that without having to pay more for an industrial scale custom build.

      • by shilly ( 142940 )

        If renewables were so damn hard to manage, then the UK would be absolutely fucked, because we routinely get about half our power from wind (plus a bit of solar). And this is with years and years of the Tories in charge, who have no love for green stuff. But funnily enough, our grid is nice and stable, especially compared to US grids that are much more fossil-fuel dependent, and renewables costs have continued to fall. New nuclear is eye-wateringly more expensive for us than new wind -- see Hinckley C* (

      • It was not that long ago when solar panels were not this cheap. They were so expensive, even using free sunlight as fuel, they could not compete with fossil fuels. This dramatic fall off was happening just as we were watching.

        Same thing will happen to batteries. Solid four hours pumping 375 MW batteries that replace gas powered peaker plants. Its happening already, so many utilities are replacing retiring gas plants with batteries. So its just a matter of time before we can absorb all the excess solar pro

  • Traffic jams eh? So we have a source of power that will never be able to produce enough power that is producing so much power that they are destabilizing the entire power system?

    So destabilizing the power grid they these unworkable solar panels must be punished.

    I see - so if Australia converted over to solar and storage systems full time, there would be so much power that the country would vaporize, because too much power would be produced.

    Bullshit.

    • Power supply needs to match power demand at any given instant.

      If supply exceeds demand, the grid voltage and frequency will rise and potentially destroy (literally, physically destroy) the generators. If that starts to happen, power plants will disconnect from the grid to avoid damage, which can trigger a cascade effect that brings the entire grid down.

      If demand exceeds supply, the grid voltage and frequency will drop causing brownouts, which can potentially damage or destroy end-user equipment. If that sta

      • So what is necessary here, ultimately, is for the utility to have the ability to turn off solar PV remotely should there be no way to use the power they're making. Storage is also really good here, because you can effectively summon demand without wasting it, and use it later when you need it.

        You're missing a third option, which is flexible demand.

        A lot of industries can modulate their demand, but currently don't because there's no reason to. If you set up a pricing structure such that excess electricity is super cheap, you'll get industries restructuring to take advantage of it. It might be a smelter, it might be a refrigeration plant, it might be a battery bank and energy reseller, but if there's margin to be made, someone will step in to make the money.

      • Seems like you found the problem

        Problem is, you can only throttle down some power stations just so much before they stop operating and shut off completely. (Not unlike how you can reduce the idle on an engine only so much before it just stalls out, to use the requisite car analogy...). That can be bad since those kinds of stations (read: coal) can take days or weeks to get up and running again.

        Stop subsidizing inflexible, unreliable, slow to start coal. And use that money for more storage instead.
        Just li

        • by sd4f ( 1891894 )

          We want to get rid of coal anyway don't we?

          Australia doesn't want to get rid of coal. It's a huge export, they have plenty of it, and too many people are making too much money from it.

    • Traffic jams eh? So we have a source of power that will never be able to produce enough power that is producing so much power that they are destabilizing the entire power system?

      No

      So destabilizing the power grid they these unworkable solar panels must be punished.

      No

      I see - so if Australia converted over to solar and storage systems full time, there would be so much power that the country would vaporize, because too much power would be produced.

      No

      Bullshit.

      Yes, you entire post pretty much was that.

      A big problem with electricity generation is matching supply and demand, and solar generates most of it's power when it is not needed, and doesn't produce any when it is. But unlike every other energy producer that operates on supply and demand economics, residential solar generation gets paid all_the_time regardless. So it's not about too much power, it's about too much power at the wrong time, in a market that based around supply/demand pricing. The fix is

  • by K. S. Kyosuke ( 729550 ) on Thursday March 25, 2021 @07:11PM (#61199328)
    Are you telling me they didn't consume the exported electricity? What was the point of those overflows if not the reduction of transmission loads and fuel consumption, then?
    • by caseih ( 160668 )

      The electricity was consumed, yes. But the issue is with the baseline generation stations. It's more costly to shut them down when there's a glut of electricity being generated from solar, and then costly to bring them back online when the solar glut is over for the day. So it's cheapest to encourage solar users to not sell so much by the grid operators charging a fee to the solar generators to take their power. Grady at the youtube channel Practical Engineering has a great post recently about the complex

      • So it's cheapest to encourage solar users to not sell so much by the grid operators charging a fee to the solar generators to take their power.

        That's the dumbest thing I've heard today.

        What are solar panel users supposed to do? Go up on the roof and cover them up? Drop a pole into the ground and try to dump all the extra power?

        The cheapest thing to do is to use the power. Sell it for $0 if you have to. Charging the generators for doing what they can't help doing is asinine. Set up a pricing structure so that someone will use the power. It's there. it's essentially free. Doing anything to discourage production is amazingly stupid.

    • by robbak ( 775424 )
      There are also local problems - in a number of places around here, solar systems provide all the power needed in a neighborhood, so power has to be pushed back through the pole-mounted transformers onto the 22kv transmission lines. These were not built for this task, so the local voltage climbs up beyond 240. This causes the solar inverters to shut down, and as they are grid-tied, that means they don't provide the house with power either.

      If they adjust the taps on the transformer to keep the voltage within
  • by quenda ( 644621 ) on Thursday March 25, 2021 @07:21PM (#61199354)

    Negative energy prices are not a new thing for industry, as the grid has to constantly match supply to demand.
    But with increasing solar and wind power, it is becoming more of a problem, and the grid will need to be able to shut off rooftop solar systems in future.
    It makes no sense to be paying consumers for rooftop power at the same time as paying industry to dump it.

    https://www.google.com/search?... [google.com]

    This is not nearly as weird as the negative oil prices in the US last year!

    • All that is already factored in to the prices we get paid for our solar. It is adjusted each year, and is a lot less than the average wholesale price.

      • You're are missing the point. The wholesale electricity market for most of Australia is priced in real time based on supply and demand (yay free market!). You can see this here: https://aemo.com.au/en/energy-... [aemo.com.au]

        So for every other generator, they buy and sell at market rates at market prices, in real time. Whereas residential solar 'providers' get paid 24 hours a day 365 days a year which is crazy. So even when no-one wants the electricity you generate, everyone else is forced to pay for it. This is not h
        • I'm not missing the point. I'm aware that the electricity market is priced in real time. But just as residential customers play a flat rate, regardless of what the current market wholesale price is, so we get paid a flat rate for the electricity produced. Retailers will adjust their prices yearly based on what they think the wholesale price will be, on average, and (at least in Victoria), the government sets the price that my solar gets sold for. That price already takes into account the amount of time elec

        • You are confused. The household is paid by the retail power service, who then aggregates energy delivery back into the grid. At some times in the year they are paying me 20 c /kWh, and charging somebody, somehow, $14.70/kWh. It doesn't take many hours of that to pay my fiT for the entire year.

    • No.
      The opposite.
      You shut off the coal plant, so the solar power is used.

      A no brainer.

      • by quenda ( 644621 )

        You shut off the coal plant, so the solar power is used.

        A no brainer.

        I could call that a "no brain" comment, but really it is just ignorance of your own knowledge limits. Think you are an expert on power engineering?

        On the short timescale, one advantage of solar panels over coal plants is how quickly they can be turned on and off. On the longer time-scale, the coal plants are already shut down, and solar generation exceeds total demand.

        • On the short timescale, one advantage of solar panels over coal plants is how quickly they can be turned on and off. On the longer time-scale, the coal plants are already shut down, and solar generation exceeds total demand.

          On the even longer timescale that coal plant (or something else) can use the excess solar to turn CO2 back into coal (or some other fuel).

    • by AmiMoJo ( 196126 )

      Negative energy prices are only a problem if the goal is to make money. If the goal is to keep the lights on in a sustainable way, and enjoy the benefits of better than free energy, then they are fine.

  • if i had a good solar panel system, i would have the powerlines from the grid removed from my house, go off the fucking grid, call the electric company and tell them i dont need their services anymore, shut off the electric and dont expect a any money from me anymore, these utility companies think they own their customers, and that has to stop
    • by I75BJC ( 4590021 )
      All this requires is an electrical switch,
      My house generator turns on when the Power Company has an outage.
      My generator stops when the Power Company restores power.
      Works flawlessly in the USA
      Why can't an electrical switch be used in Australia?
      You know, to save electricity when it is not needed.
      What does America have that Australia doesn't have?
      • What does America have that Australia doesn't have?

        I can't speak for the whole country, but where I live I have reliable electricity so don't ever need the expense and effort of a generator. First world problems eh?

      • What does America have that Australia doesn't have?

        America has less reliable power supply. needing a generator in Australia is practically unheard of except in remote communities.

        • by quenda ( 644621 )

          America has less reliable power supply.

          Partly due to the more extreme climate. We don't usually worry about ice or tornadoes bringing down powerlines in Australia.
          But also economics. We pay a lot more for electricity, and other infrastructure, to make it extra-safe and reliable. Many Australians would probably be willing to give up some reliability for US-level prices. And a lot of Americans could not afford to heat their massive homes in sub-zero winters if natural gas cost as much as I pay.

    • Long as there are no laws requiring a meter even if not used.

      • I'm sure I read here on /. that some U.S. towns have done just that: require that disconnected residents continue paying a utility fee.

        Can't find it, though.

    • So do it! these companies supply you with a service and do it to make money, hence they expect you will be charged more when you cost them more. The reality is going off grid for most houses would never pay for itself in the system costs (especially in Australia). The wide adoption of solar does create problems when Grid connected (nice problem to have).
    • by ishmaelflood ( 643277 ) on Friday March 26, 2021 @01:34AM (#61200222)

      I have an off grid house. You will need a generator, and a big ass inverter and battery pack. It's doable, not madly expensive, but not cost effective. Say $35k for a reasonable house sized system.

  • Worst thing about this proposal is, people don't have a way to control how much energy they are pushing back to the grid. So on the one hand government wants to tax people putting excess energy back onto the grid, but on the other hand those same people have no way of limiting or restricting. At least not with current dumb inverters.
    • by quenda ( 644621 )

      Worst thing about this proposal is, people don't have a way to control how much energy they are pushing back to the grid.

      The proposal is providing some incentive to fix that problem! This is a good thing.

      • by shilly ( 142940 )

        But it's the wrong order of fixing problems. Because there are other problems that need to be fixed, like driving down coal usage vs solar. So rather than incentivise domestic solar producers to produce less, the right policy solution would incentivise coal producers to store excess. The obvious route would be incentives (stick and carrot) for them to put storage in place. And then they could transition to an energy storage business over time, as more solar comes on-stream and more coal goes off-line.

  • This is pretty much it.
    You get a bill. You get a bill and you LIKE it.
    OR ELSE!

Experiments must be reproducible; they should all fail in the same way.

Working...