Payment to energy companies for solar panel input

An electrician told me that there is no point using dishwasher etc during the hottest sunniest time of the day and that the electricity generated from my solar panels just goes straight to the grid. Is that correct? If its not, is it still environmentally friendlier to put appliances on during the peak solar generation period. or - Do I go back to putting appliances on at 10pm when electricity is cheapest ?? I would be very grateful for advice.

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I suggest you need a new electrician.

A properly operating PV system first feeds the premises, and what is not used by the premises goes into the grid.

Yes because you are using the (renewable) power from your PV panels rather than that generated by predominantly fossil fuels.

The economics question can be different, especially if you live in an area like Melbourne and the cloud cover is predictably regular and you need to run your appliances.

One way of looking at it is if you use your PV power (eg while the sun shines) your cost per kwh is the FiT ($0.102 in my case) that is the foregone payback from the grid if you use it rather than export it. Some think of that as ‘free’ but there is that cost of ‘lost opportunity’ to sell it into the grid.

My off-peak is about $0.20 and peak about $0.30 so I often run the dishwasher overnight when it gets full since during winter the day might be overcast and it is a punt when it is most advantageous to run.

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This is uncertain advice. Assuming that you do have a deal where you are paid for your excess power the best thing for you to do usually is to use your own power first. The reason is simple, the rate you get for what what you sell will usually be less than you have to pay when you buy from the grid.

The exception is if you are getting a higher rate for selling than you buy for. Study your power bills to check this out. I seem to recall there is software that will help do these sums and tell you the best strategy. Can anybody help here?

For most people at most times the more you can use discretionary power on sunny days and the less you use on cloudy days or at night the better off you will be.

Note that heat is not a positive but light is.

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What is your Feed In Tariff (FIT)?

If your FIT is the current average energy pool price (~$0.08-0.10), then it is best to use this when the sun is shining. The difference between FIT and imported metered electricity is what you save using your own PV electricity.

If your FIT is similar to or greater than your import/meter price from the grid, then financially it may be better to export when the FIT exceeds the metered imported electrcity tariff…but potentially not as environmentally friendly as using your own (electrons from the grid will be from renewable and non-renewable generation sources).

Only if you have a grid connected system and you generate more electricity from your PVs than you are using. Excess will be exported.

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All depends upon your PFIT status. We get 66c/kwH for what we feed in and what we take out only costs 30c. So we only use appliances after the sun goes down and we end up with no electricity bill :slightly_smiling_face:

And in what magical location do you live in? Where what you take from the grid is less than half the cost of what you put in?

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Perhaps Victoria where the early offer was a FIT of 60 cents per KWh.

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I get 66c/kWh in Melbourne because I outlaid $8K on one of the earliest solar systems that came out - it came with a high upfront cost, but a very generous PFIT.

So yes, I get twice as much for what I put in as what I pay for what I take out :slight_smile:

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Like all good things, the high FIT won’t last for ever. In Victoria, it expires in 2024 and will fall back to the current FITs.

As standard in most States that have generous FIT, these can fall back to current FITs if one carries out an action (sells the property/ownership change) or PV system modification (e.g. increase inverter capacity) prior to 2024.

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I think this issue is still developing. AEMC are considering an actual payment by solar panel owners if energy is pumped into the grid at times of high grid voltage. Claim is that the high grid voltage causes havoc for appliances and electronic gear. If this is factual then it indicates promotion of solar before system planners considered the full impact of solar. Looks like distribution asset privatisation disrupted system planning at the same time as the global warming panic set in.

Much of the time it is not factual. As I demonstrated to my brothers electricity supplier, the highest voltages occurred at night, when there was no possible contribution from solar. They adjusted the transformer tap and now all is good, whereas previously his inverter often cut out during the day due to the overly high transformer voltage tap.

In some cases where the supply cables in the street are too small for the load (and supply from PV systems), or the transformers don’t have enough capacity, then solar can cause the line voltage to vary more than the standards (full range 216 -253V, nominal 230V). However, in many places transformers are still set to the old 240V standard, so it is much easier for PV systems to push the voltage over the high limit.

So generally this is going to come down to PV system owners paying for inadequacies in the supply system. A system on which much was spent on gold plating for extra loads a decade or so ago, when they were blind to the coming renewable energy revolution.

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Thanks for reply Gordon. AEMC wasting their time…don’t think so. The reworking of the distribution system you refer to would cause a cost of supply increase way beyond any solar input benefit. I think all parties need to open-mindedly consider the big picture. Decade or so ago Australia had had some of the cheapest distributed electricity in the developed world. Now we suffer some of the dearest. Why…privatisation, profit seeking , green panic driven subsidies etc. etc.

The “reworking” of the distribution network, (IE redesign, configuration, upgrade, operation) is part of the plan.

The addition of Solar PV, wind generation, storage etc is happening. It’s necessary to decarbonise the grid and increase generation to meet the future green energy needs of other sectors including transport.

It’s not an option to put off change. The transition requires investment. Whether that costs the consumer more is up to government policy settings. Regardless of the financial impacts, not spending the money is not an option.

If there is cause for consumer concern about the costs is it about how well the transition is managed? Hopefully with more foresight and better intelligence than the NBN communications upgrade. Or does that also answer the question?

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Thanks for reply Mark. This is just part of a much bigger question. Why is there such pressure to change our established and previously cost-effective energy systems?
Profit driven by manufacturers who can see the benefits to them by prematurely replacing the electricity and vehicle technology? “Feel good” benefits to Thunberg/Gore supporters?
Unfortunately very few bother to make the effort to go back to square one of this issue. Over a decade ago Dr John Nicol examined the behaviour of CO2 in our atmosphere and concluded that the IPCC pronouncements exaggerate the impact by a factor of 5 to 10. No one , to my knowledge , has refuted Nicol’s conclusions.
Yes ,climate is changing but degrading our energy/vehicle arrangements is not a solution, especially as it creates problems of its own e.g. major battery blow-up in Victoria a few days ago.
Solar goes well in remote locations and as large “farms” of panels where the unreliable output can be managed along with other energy sources. In the bigger picture suburban solar is a doubtful proposition.
You refer to a “plan”. I suspect planning of the level needed for a reliable, cost-effective electricity distribution system fell over during the privatization push a decade or so ago and is just starting to re-appear via AEMC and similar organisations.

In some situations it is not cost effective. Secondly, it was not designed with distributed generation in mind and so risks becoming unstable. Distributed generation is a fact of life that must be dealt with.

Then you do not read very widely. This is off topic in several ways as are your digressions about solar reliability. I suggest we keep this thread about the finances of solar feed in tariffs.

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Syncretic, thanks for reply.
Would appreciate a link to refutation of Nicol. Please note Nicol, a physicist, has taken the analysis back to “square one”…the behaviour of atmospheric CO2 as opposed to the assumption-based modelling upon which much of the IPCC publication is based.
Solar feed in tariffs are a very mixed bunch.
I suspect you will find AEMC’s proposals are an attempt to counter the impact of excessive solar feed in. So I argue that the thread has to be aware of AEMC’s related proposals.
On a more positive note we should be seeking to use our solar output “in-house”…residential water heating,dishwashing, pool filtering etc.

There have been a few topics about climate change in various forms on the Community, including posts from deniers, misinformation peddlers, references to reports from climate scientists reflecting the dominant view, and references to those who have published dissenting opinions. You can find them using the Community search tool and for the purposes of consumer issues they have run their course and have been closed.

The following is somewhat of a paraphrased summary of them.

Modelling is accurate* and the conclusions have been diluted by political forces, conclusions have not been sensationalised by science. Unfortunately the media have become click-bait experts and routinely misrepresent or misreport what and sundry to attract clicks that often go to poorly written (over)summarised bite sized snippets that on one hand are designed to stoke rage, or on another to minimise everything.

There are reports from scientific organisations from climate research facilities (NCAR, CSIRO, BOM, DKRZ, ECMWF, JAMSTEC, EC, and many others that generally are in agreement, to NASA, to various national defence establishments that recognise climate change is a national security matter.

The telling graph from NASA, about modelling accuracy, is

One of the original premises of the FiT was that it would eventually go to zero. Introducing what is a penalty for exporting in whatever guise is a relatively new idea.

My understanding is after the very early days where policy was to be a catalyst to encourage solar adoption, it has been moving toward ‘self-use’ and I am unaware of anything to the contrary although concepts have moved from individual roof tops to localised community sized systems…

In the early days it was about generating as much as you could because of the high FiTs. Over the past few years it has evolved to generating as much as use when you use it. To wit, instead of all panels facing North best practice tries to face some to the East (brekkie time) and the West (home from work, dinner time), hoping that makes any point.

As technology evolves there is ample historic evidence that in response policy, law, infrastructure and society change with it, although rarely in synch and often not timely.

This topic began with the question

That has been addressed, so rather than have the topic digress to other issues I am closing it.

* disclaimer: While not being a climate scientist I spent decades working with many of them on 4 continents and thus am biased.

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