Network Charges to Export (Solar) to the Grid? Solar having an impact on 'Big Power'?

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The reduction in output can be offset a bit by raising the voltage setting in the inverter to it’s highest permissible level, in Qld this is 259.9 volts. If line voltage goes above this the inverter will cease exporting and output.

It’s a poor workaround as voltages should not get that high in the first place. All that being said, if you are near a transformer for a group of houses then you may suffer very high line voltages that approach or exceed this level. The reason it is possible to see it this high in this type of situation is that the energy supplier has to ensure that all the connected properties receive adequate power to allow the equipment they have, to run. Again partly a one way design issue I think and a cost saving in that the amount of transformers and other work is reduced to the lowest amount possible for a given area.

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One power retailer is trying to sell this idea - who could resist? :wink:

Virtual Power Plant (alicespringsfuturegrid.com.au)

I haven’t done the calculations in detail , but people on legacy FIT probably shouldn’t apply …

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The same principles apply to both small (inc. roof top solar) and large generators. AEMO instructs generators to cease exporting generated electricity to the grid, to protect the operation of the main grid. Curtailment has been used for large generators since integrated grids were first established in Australia many decades ago. The curtailment of domestic PV solar is in some way catching up with the existing exporting controls for other generators.

The long term 20% curtailment figure also sounds low. About a decade ago, there was talk of percentages significantly higher than this due to the need to have significantly more/excess generation required by renewable energy sources (their fluctuating generation nature…more and greater geographical distribution of generation to try and balance out fluctuations in generation to meet demand). It would be interesting to see what assumptions they have made for the 20% has it may be based on very high network storage to buffer potential future curtailment.

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Not exactly as it also depends on what your supply agreement says, does it not?
Assuming for one moment it does. Is there a notable exception for grid connected rooftop PV where the consumer will be forced to curtail production even if they are self consuming 100% of their output at that time?

It looks like a solution that is not well thought out and will hurt many with smaller PV systems unfairly. To keep the washing machine or dishwasher running those consumers will have to pay to take power from the grid instead of consuming rooftop PV at no added cost.

In other topics there are suggestions a great way to maximise self consumption and value from rooftop PV is to use it with a time switch to power a storage or heat pump HWS. That would seem like unreliable advice with curtailment is applied to those users. It’s all to the benefit of the big generators, distributors and retailers bottom lines.

If there is a genuine need to curtail rooftop PV, should it prioritise limiting larger systems or exporters over smaller? Export limiting can be added to systems, the cost being less of an impact on owners of larger systems.

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No, all generators need to comply with the relevant electricity laws and rules. Agreements don’t include guarantees to supply all generation or exclusion from the laws/rule. If they did, the electricity system in Australia would be a dog’s breakfast.

It is fair, as the network operator can’t control local use. Even one can’t guarantee 100% of generation will be used 100% if the time.

It isn’t unfair. If one has a grid connected rooftop PV system, they are bound to the same laws and rules as larger generators. If one doesn’t agree with the laws or rules, one can have their PV system disconnected from the grid.

This may be impossible as the network operator will determine what actions are best to protect operation of the network at a particular time under the prevailing operating conditions. Excluding one form of generation will increase risks associated with network reliability. One should be careful decisions aren’t made to protect individual self interests over the energy security of the community.

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That’s the answer to a different question. Home PV owners are not treated exactly the same as large generators. Which rules and regulations are ‘relevant’ depend on whether one is a major generator, a distributor, a retailer, a residential customer, or …. There are so many options. Until the recent and progressively approved changes in the regulations, there has been zero provision to turn off small scale residential PV export.

The controls on residential customers that have been exercised to date have been through the approval to connect new installation agreements. These include the voltage parameter setting of inverters or systems and connection of AS approved equipment. Other restrictions include limiting the size of the connected system, or additional equipment requirements that enable export limiting from behind the meter. In comparison the big generators are treated very differently including requirements of guarantees to supply, and variable rates of payment for supply.

The network operator has had the ability since the first residential PV to grid connection, to control local use. Actions available included setting limits on the size and number of connected systems as well as setting export limits through technology.

Perhaps the regulator should have acted to apply greater restrictions in years past. It did not and Government/s have by agreement been supportive. If suggesting that applying changes to residential users after the fact is fair, we can all draw conclusions. Fair could include grandfathering all existing residential PV customers arrangements over 10 years, similar to the legacy arrangement for high feed in tariffs.

Note the priorities set by the National Operator and Regulator include upgrading to enable increased connection of distributed energy resources. Why this is not as advanced as it could have been is a question of leadership, policy and politically coloured. Also outside the scope of the community to resolve.

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I don’t think this is either new or unique to solar - but it is of course new to most households when they first get solar.

The remainder of this reply is only about the type of curtailment that is directed by the energy market operator.

I suppose that is better than negative FITs.

I think it will not be applied retrospectively i.e. only to new installs. Follow to the linked article about the introduction of curtailment powers in WA:

Under the regulations, customers installing new or upgraded solar panels will be required to have inverters that allow authorities to switch off production in emergency situations.

So an existing install, whether vintage or done yesterday, may not even have remote curtailment functionality and won’t be subject to it.

If you choose to expand your system later on then you would suddenly be subject to it - but that kind of makes sense. Everybody is telling us that there is too much solar (at certain times) and you go and expand your system.

So if you don’t currently have solar and you are planning on putting it in then take curtailment into account when deciding on whether it will work out for you. “Unfair” would be if they changed the conditions after the fact.

I don’t see how this specifically penalises households with high self-consumption. It just means that they don’t have the right equipment for the job i.e. to ensure that they can operate normally when being curtailed. The linked article fails to explain this properly. Again, if you know this up front before installing solar, you take it into account and plan accordingly or, more accurately, the company that you are getting to quote explains this to you and designs accordingly.

So when the article says:

With some exceptions, this prevents the household exporting solar energy, as well as using solar to power its appliances.

Instead, with the panels switched off, the household relies on mains power.

it doesn’t explain what “with some exceptions” implies and when it applies.

If my system were subject to curtailment, it would cease exporting but it wouldn’t start importing. So it would address the supply side but it wouldn’t address the demand side.

But then, struth, those are purely forecasts over the period to 28 years in the future. I call GIGO. What were the one thousand assumptions that went into those forecasts? (You ask the same question.)

As with some other long-term forecasts, it is also relatively lame to forecast something bad to happen when you can do something about it.

If grid operators are really saying that this will happen over the next 28 years, they are free to reject new applications to connect to the grid at some point in the future - or to place conditions on the approval of new applications - or to take other more positive measures to avoid bad outcomes over the next 28 years.

On the consumer side there is also the economic potential to redirect investment away from bigger and bigger installs (i.e. away from bigger and bigger kW of peak panel power) and into e.g. household battery and/or EV as surrogate battery.

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This proposal reflects a ‘never let good work go unpunished’. The grid and thus the retailers get cheap power from roof top solar but their profits are not high enough for them, so off they go. Their incremental costs seem to be modernising the grid to account for feed in not just consumption. Nothing seems to be part of their business cost excepting profits (obviously not a cost unless one accepts less profit no matter how big can be a ‘loss’).

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Time to take a step back and look at what the electricity industry might look like in 15-20 years.

Fossil fuels are dead, and electricity is generated through today’s sunlight (whether solar, wind, wave) or geothermal. The cost of solar panels has fallen, and the cost of storage has taken a big dive (there is a lot of work being done on next generation power storage at the moment).

In such an environment, is there a place for a centralised energy grid? Sure, it would make sense for a household that can afford the initial outlay to produce their own electricity, but what about a community? Could a housing estate effectively go ‘off the grid’ and provide its own power without having to maintain hundreds of km of wires and the associated electricity infrastructure? Maybe a block of apartments would own a share in a generation array (solar, wind, whatever), and have responsibility for maintaining its own connection?

There will still be a place for a centralised electricity retailer - whether for apartments as mentioned above, or in providing CBD electricity - but will it be the kind of monolith we have today?

And the crucial question: how does the regulator smooth the path from today to tomorrow?

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My guess is that a compromise network size will become popular but each will depend on population density and capacity to have wind or solar at the location. Big cities will probably stay with the big network but connected to newer generators and supplemented by household solar.

Small towns up to small cities will have their own networks as the need for big networks to go with big generators will have passed (as they can be a long way off) and we will find that for a modest density a centralised local generation system and a small local network is more economical than each house having its own. There will still be economies of scale after decentralisation.

There are two aspects in particular that bother me. One is having spent billions to build new connectors and other hardware to stabilise the net under pretty much the current configuration there will be little appetite or money for further change for a long time and secession will be discouraged.

The other is that there will be resistance to a model of smaller clusters even if they are cheaper as it will accelerate the death spiral of the big network. When the poles and wires were first built there was a transition waiting for enough customers to join up to make the network investment worthwhile. How about the reverse, where a diminishing number of customers are sharing the whole cost of the big network?

If it is eventually going to be switched off, or more likely have chunks switched off progressively, there are going to be some very difficult dynamics to manage and still keep everybody supplied at a sensible price. Is this where public money has to fund grandfather deals to keep the lights on for those who can’t afford shares in the local collective? What form will it take, bulk subsidies (or cheap loans) for local schemes or individual support, or something else? This all might have been easier if the generators and current networks were in public hands.

An current example of the pressures, that will only get worse, is the failure of people to see that any transition will be costly and so right now they blame renewables for short-medium term price rises.

If families are hurting they don’t want to hear that we have no choice or that in the end it will be better, they want somebody to blame. NSW is about to have an election featuring the cost of living as an issue - something that is largely out of the hands of all the parties concerned.

There are so many modes of failure possible due to our rulers playing politics and being short sighted - traits that they are already well known for. The need for policy and funding that are durable beyond the life of any parliament is bleeding obvious but we as a society have failed at such tasks before. Maybe we need a war against a common enemy to put aside political differences - it wouldn’t be hard to arrange :cry:

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Snowy Hydro 2.0 comes to mind, but maybe that investment is worthwhile as a bridge from old to new power generation and storage, and hydro may remain a good/efficient source of renewable energy.

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For battery storage, this has been forecast for a few years now but is yet to eventuate. In fact, in the past couple of years battery prices have been going up and optimistically, current forecasts are they may start declining in about 2024. This forecast decline has many assumptions with the major one being substantial increase in raw material through to manufacturing capacity to meet li-ion demand for storage, transportation and other uses. This is a big if.

For other storage such as hydro, the low hanging fruit/cheapest options have already been utilised. The incremental unit cost of additional storage will increase as less efficient options need to be developed to increase network storage. As high capacity storage such as hydro will be key to network stability as well as generation capacity which will be multipliers of peak load, the overall storage costs won’t be declining.

Networks are and will always still be needed. If we didn’t work, get educated, want medical treatment etc and only consumed what we produce on and can physically store from our own house rooftop, then it could be argued that a transmission/distribution network system may not be needed. Otherwise and realistically it is impossible to provide sufficient supply to meet modern life without a network system that allows flow from generation/storage to consumers. In a renewable generation environment, the grid will spread further and wider to try and deal with the higher fluctuation of renewable generation sources.

This change will also have substantial cost impacts.

This article from the Columbia Climate School summarises what many in the industry already know…

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During the transition this will be so all over the world, however the article is rather Eurocentric.

I am optimistic that Oz is in a better position than Europe due to access to better solar and wind generation areas and that afterwards we will end up with cheaper power than now.

Another reason I am guessing our power will end up being cheaper is that with segmentation of the network and better control, transmission losses which are rather high due to our long lines will be reduced.

Thirdly, if you take into account health consequences in your costing thousands of lives and considerable morbidity, worth billions of dollars, will be saved annually by eliminating pollution from FF power stations and ICE use, and a great reduction in coal and gas mining. The current cost of such air pollution is hardly ever mentioned so it may slip away unnoticed when it is much reduced.

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While being Eurocentric, the same principles apply here.

While each country has different opportunities and constraints, the cost of electricity at the point of consumption will increase through the transition to renewable energy.

Europe has shorter distances between generation and consumption (and has nuclear), with wind (esp. off shore) overall being more reliable than that of Australia. Australia has a solar advantage, but solar comes with significant storage and transmissions costs. Particularly transmission if generation is located on less valuable/less constrained lands. Australia will also be have substantially more storage costs (and higher generation capacity) than Europe for each unit of energy as we won’t have the luxury of nuclear to balance out fluctuations in generation (which is currently occurring in Australia through coal/gas but won’t exist in the future).

No where is it cheap, no matter how optimistic one is. As outlined in the article, politicians and environmentalists need to be realistic about future costs, as cost of renewables generation per unit of energy at the point of consumption will increase substantially as traditional generation sources are phased out.

An investors perspective is also interesting…

Unfortunately the media has reported statements of politicians and environmentalists without critical review and it has created an (incorrect) belief power must be cheaper in the future because renewables are cheaper than coal/gas today when there are a mix of generators suppling the energy market. The past is very different scenario to the future.

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Add to that optimism the continuing rapid developments in storage and conversion technology, the future can only turn out better than we might forecast.

There’s always a tendency for any discussion of prospects to lean to the two extremes. The greatest shortcoming IMO is we all tend to look at tomorrow through todays lenses. 2050 is 25 years distant, and so much will change along the way.

Look to everyday electrical rechargeable storage technology and inverters in use and the capital costs in 2010, 2000, or 1995. It’s difficult to see how any of these products forecast the capabilities or relative costs of todays products. Hence when we look forward 10-15 years should we be saying that the storage technology will be more capable, cheaper, and likely not relying on lithium as we do today? Even though we can’t be certain of exactly how they will be designed or the cost.

Similar might be asked of our centralised energy distribution grid. Frequency stability is a legacy of the age of steam powered rotating machines. There are other ways to manage energy distribution and account for AC generation frequency stability/power flow. Is it in the best interests of consumers to accept the positioning of the energy industry vested interests on how they see the future network design, operation and energy flows (profits) evolving?

The technical discussion is self evident. The energy system can only work one way, because it’s the only way that suits those taking the profits. It’s easier to say that the grid can only work a certain way than not. The alternate propositions include greater distributed resources and localised self reliance. Assuming local resources remain reliant on AC coupled distribution there are technical challenges to managing synchronisation by remote communication. Alternatives such as DC network interconnection is already a proven alternative, more effective over distance than AC. It’s just one challenge to the status quo.

For many households, those who can be solar PV enabled at the home or …. otherwise through local support, the next step change in home battery technology will deliver relative independence. The value will come not in export, but in averted purchases of power. Especially if those intent on saying we will all need a bigger and more expensive grid can talk up the cost of supplying power to the average home.

There is scope, although the bids for control (profit delivery) are self evident?

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I think the question you are raising also touches on what a city will look like in 15 - 20 years (and what we want a city to look like).

At one end of the spectrum … a sprawl of quarter acre blocks each generating and storing their own power. There would be limited need for a distribution network, however, as consumption and production are unlikely to be exactly matched, it seems unlikely that everyone in the city would want to be “off grid”.

At the other end of the spectrum … a never-ending sea of soulless shaded tower blocks packed closely together (and a population an order of magnitude higher). There is no hope whatsoever of generating enough power within the residential area. So the existing “conventional” model looks more likely. And the cost benefit analysis for building the transmission lines to service the city works out fine.

Also the unresolved issue of rental properties.

An isolated apartment block could perhaps be clad with PV material so that it meets more of its own power requirements.

Then of course there are more radical possibilities, some of which we can’t even imagine at this time. Predicting the future is always difficult, sometimes embarrassing. :wink:

Or the government? So far the government has encouraged individuals to put up their own capital in order to generate their own power. That decision has set us on a certain path (to some of the highest rates of household solar installation in the world).

Do we envisage the government reversing course and getting back into the business of generating electricity? Or tilting the playing field to get big business to do so?

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This is more likely to be the case in Australia and is what is being forecast by urban planners, government, think tanks and futurists. The urban sprawl which has occurred historically in Australia has lead to many problems, many which will be exacerbated in the future - hence shift towards densification like that which has occurred in many other countries.

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But is it what we want?

And what is the meaning of a “forecast” by government when it is government policy that will determine whether it comes to pass? It is not a forecast. It is a decision.

But we digress …

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We don’t have a choice. Sometimes what it in the best interests of a community as a whole overrides the interests of an individual. It happens in many situations and this will be another.

There will still be some single dwellings on a single lot, but, it will be limited to those who can afford the privilege of having such residential arrangements.

The move towards rationalising urban footprints has started in many Australian cities with restrictions on new development areas and encouraging infill and densification.

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I was speaking to an Electrical Engineer about this the other day and I was also looking at the forecasted trends for energy usage in NSW.

What I looked at was Ausgrid and other distributors forecasting a staling * of energy - that is the forecasted usage has stagnated - due to the uptake in solar that is going on.

The issue is that the peak loads need smoothing - and the current network is not built for that. Solar peaks on cool sunny days. Then the energy generation equipment has a hard time ramping up when demand picks up if the sun goes away or at other peak times like in the evening.

Batteries are not a viable option right now, economically or environmentally.

And I am an installer myself with a local business and happily say this.

But the trick is as an installer to install systems that promote future fool proofing and flexibility. We can only do so much and the field is constantly changing. It is wise to install a system that has the possibility of being retrofitted to a battery, as batteries are an energy storage unit.

For now, we can be smart and shed some power and store it in other means - mostly in the form of hot water.

Either way, the OP is right that credits will continue to go down, as they have done for the last 20 years. There is nothing that will stop this - it is only inevitable as the technology gets better and better.