Losses from lines are relevant no matter how you configure your connections.
All lines have losses but they are more significant at low voltage. Very high voltage is used, despite losses in transformers, for long distance transport to keep down the thickness of wires, which keeps down costs of wires and towers. At the other end it is advantageous to have your last transformer (say on a 11kv line) as close to the 230v consumer as possible to minimise the length of low voltage line.
So even if you are building a distributed generation network such factors must be taken into account unless your model allows nothing larger than single houses or tiny clusters. We love our home PV arrays but larger systems are more cost effective. For wind the one generator per house idea isn’t workable as bigger is definitely better and you typically don’t put the turbine where many people live but up a mountain or on a windswept coastline, or even out to sea.
The original post in the topic raised the prospect of households being billed a network charge for export of excess solar PV.
From an electricity distributors viewpoint, there was a potential for loss of revenue through reduced metered electrical power consumption across their network. That any power exported is consumed and metered at another user/s limits the distributors financial loss to income not received due to self consumption of solar PV.
It’s worth considering that residential exported solar PV is typically only transmitted over short distances. The losses in the local network due to feedin are similar to the local line losses, perhaps less. There is a reduction in the network demand on any external supply where solar feedin is added to the local supply. Solar feedin results in fewer external generating and transmission losses across the network.
Assuming a local distribution substation has a load side that is generating greater than the local demand there is no need to transfer the surplus using low voltage (230V) elsewhere in the network or town. The transformers and equipment will efficiently redistribute the surplus using the HV network (typically 3.3kV or 11kV and above).
There are separate considerations of voltage regulation and overall network control when this becomes significant. It’s one instance where larger scale distributed power systems EG batteries, at local or zone substations become beneficial.
Is it worth considering for properties with residential batteries the benefits of changing how FIT’s are determined?
In the Victorian big battery example, the payback is not based on every day steady state generation. The cost benefit is in supplying power during periods of peak demand and in response to sudden changes in supply/demand. Generators are paid very considerable premiums to meet peak demand.
A residential battery install can achieves two outcomes.
Firstly it can remove during peak periods grid demand by the connected residence as the battery enables self consumption of stored power.
Secondly a battery could feed back into the grid at periods of peak usage power to reduce the demand and need for increased centralised generation capacity in response.
Would it be fairer to pay consumers the spot NEM market rate for power exported from a battery during peak demand periods?
Would it also be fairer to pay battery owners a further amount based on the energy they have not taken from the grid during peak times?
A further extension would be to pay residential battery owners a nominal amount to top up their batteries off peak for energy to be returned at the next peak demand period?
It’s evident from the Victorian proposal and cost benefits attributed to SA’s battery installation that they do pay. Shouldn’t consumers have access to the same rewards?
It might just be what is needed to justify greater uptake of residential batteries through faster payback. There are real benefits of additional battery capacity in reducing the need for high cost gas peaking generation.
Interesting idea but who knows what “fair” means, and this could lead to more of a confusopoly. Related to the latter is the problem of information asymmetry.
I think this idea may be rendered obsolete by the rush by states to install their own “big batteries”. This idea would be an alternative i.e. pay residential battery owners because the state could then avoid the big cost of a “big battery”.
With any examination of the question of whether residential batteries can play a role in the grid, would be the question of whether the household is better off using the battery for their own purposes. Better off obviously encompasses financially better off (including lifetime of the battery as well as the cost of electricity). Less obviously, better off encompasses better off in terms of availability of the service. If you feed too much from the battery to the grid and then the grid goes out (unplanned) and you left yourself with too little in the battery to ride out the outage (of unknown duration) then you will not be happy.
It seems a potential unanticipated (but one that should be anticipated) consequence is a proliferation of batteries and houses going completely off-grid even in metro areas. The inevitable response may be to prohibit off-grid where mains is available. Lots of shoes are yet to drop but solar could get ugly as an investment, plus flow on effects to EVs and everything else electrical coming down the track.
Upset the revenue stream of big business - in comes politics - nothing really surprising sadly, the loser is the little guy and the environment … Of course it is more complex than that, but it doesn’t get any more cheerful in the complexity I fear …
I am not convinced it is only about revenue streams as more solar gets into the mix.
Rather than addressing grid management and updating how it works where 2-way flow is the norm, it appears circling the wagons is what our ‘best and brightest’ can come up with. Not only is there a history of pounding down our tall poppies, but another of promoting people into overemployment, whose jobs seems to be pounding down tall poppies, and circling wagons.
Some, such as my brother, are already exposed to this side of the market, being on a wholesale plan.
If they are going to charge PV system owners when the market price goes negative, then to be fair they should also being paying them huge amounts when the price hits the market cap of $14500/MWh ($14.50/kWh)* on the spot market, not the measly 6c or similar they pay now.
*corrected, need to spell etc check before posting
It is very challenging as the cost to augment the existing network isn’t cheap and any works the consumer ultimately pays for it. I can see why solar is levied instead of hitting every consumer, as the solar installations have resulted in current network problems. One could see it as a user pays system.
Current network running costs are based in 40-50 year lifes. Having to augment existing networks, replacing equipment mid life, becomes even more expensive for the operator and ultimately the network users, the consumer.
Domestic PV installations have in the past been driven by a range of factors, without much consideration on network impacts. Now the chickens have come home to roost.
They could pay based on instantaneous spot prices, but at the end of the day the average export FIT would still be well under $0.10/kW…which is the annual average electricity pool price.
Using spot prices would increase billing costs due to more complex calculations…which would also possibly be passed onto PV households making spot price based FIT less attractive.
An extra 3 millseconds processing time for the computer?
In any case, they are going to be collecting money from those exporting power, as well as charging the next door neighbour full price for that power. Double dipping to increase profits is how it looks to me.
Everyone on the grid paid for the network “gold plating”, much of which was to cater for an explosion in air conditioner use, particularly in SEQ, whether or not they had an air conditioner.
There are two reasons why all users should share the cost of any network upgrades.
Firstly the common proposition is that cheap solar power has been one factor that has helped to drive down power prices. This has been to the benefit of large users (commercial and industrial) as well as residential users who do not have solar. It has been a shared benefit. All should pay.
Secondly as any upgrades are completed all users will benefit in the increased capacity of the system to utilise more effectively local solar generation, and smart/controlled battery feed in.
Overall everyone benefits. The only looser is are those investments tied to the old way of producing power and operating the grid. A strategy that requires continued increases in capacity and costs of the NEG interconnects to source power from a centralised system, vs a decentralised distributed generation and storage design.
A further consideration is that the increase in rooftop PV is also reducing GHG emissions over time. The benefits of these reductions flow to the whole community. The community should be happy to contribute.
Reducing GHG emissions is not somebody else’s problem, or optionally not to pay for by continuing to use high carbon sources of energy.
Possibly yes for computer time, but the meter will need to be collecting significantly more data to match the almost instantaneous spot price move. Otherwise one may miss out on the $14000/MW which may last for a few milliseconds if the domestic meter only reads every second or few.
The price will be similar if the FIT is based on the average pool price and the imports are also based on the FIT (removing any network, environmental, retail etc charges). In most states, I understand that this is the case. Often consumers look at the FIT and see it is 8c/KW but the electricity they import is $0.25/kW and cry foul…but, in Australia the user pays the network charges and not the exporter/generators. One could change the system so that both generators and users pay for the network…so that the FIT and import prices are the same…but in reality, this will push up the pool price such that everyone pays more for the power anyway.
No quite true. The increase generation available from renewable energy sources has increased the generation capacity on the network. Increased supply (generation) exceeding demand has placed downward pressure on electricity prices on the grid.
In relation to domestic PV, there is evidence that it has increased the cost of electricity (which has been offset by large scale renewable generation as above) through environmental levies and network augmentation to cope with the local generation.
I ponder whether similar arguments may have been popular when motor vehicles started to replace horses and buggies. In short order there had to be roads, petrol stations, mechanics, and so on, some created by visionary governments, some by private enterprise, and some by governments/parties that were dragged along whinging about it but still found ways to profit from the evolution of transportation. There were also losers such as blacksmiths and perhaps stables who held on as long as they could, some thinking to the end the motor car would be a passing fad?
Sometimes there is a value to a cost of modernisation, unlike putting dollars in pockets that has a cost but no value, excepting to the pocket.
These are funded by the taxpayer through taxes (either personal or corporate)…unfortunately they don’t print money to spend it…or do they like they have tried recently in many countries by issuing government bonds to generate revenue as expenditure.
Even if the government paid for the augmentation, it would mean taxes are raised or other services are cut to meet the shortfall. Either way the taxpayer is impacted.
I am not aware anyone suggested there is no cost to ‘fixing’ the grid to reflect current technology.
Some things actually cost. Nothing comes free. Value of that cost is in the eye of the beholder. Some see the value, and others focus mainly on balances in pockets.
Citizens in many countries make national sports out of whinging about and trying to avoid taxes, all while whinging about the lack of services, infrastructure, and healthcare - topics varying by country.
When citizens concerns about their taxes drop out of top place, and they prize quality of life and accept it needs to be funded the narrative may change, but with partisanship and disparate ideologies being as they are I’ll not hold my breath. The Finnish routinely top quality of life league tables, and whether one agrees with those or not, they pay taxes to achieve what they have and I suspect their daily narrative about what has value at what cost may be different to our own.
