The old saw about solar power is that the sun isn’t always shining – but in a country as large as Australia, good engineering and intelligent grids can go a long way to overcoming the challenge of intermittency, according to Australia’s CSIRO. The nearly 200-page report, Solar intermittency: Australia’s clean energy challenge, …
There is a limit to how much rooftop solar PV can be used in a local area, i.e. the area served by the local area transformer. This is because the local area transformer only works one way. When the amount generated by local rooftop solar PV approaches the amount being consumed locally there cannot be any more generated, because it's not possible to send power backwards through the local area transformer to the grid. I believe the power company can even send signals to inverters telling them to limit their output if this situation is likely. The obvious solution is to make transformers which can feed back to the grid.
Re: local limit
Any power transformer, including a local area transformer, can pass power both ways, no worries. The only problem (and it can be a real issue) is that there may be local voltage issues that cannot be managed by a tap changer (if there is one in the local transformer).
Re: local limit
The other alternative is to wire most of the rooftop PV direct to the Air Conditioner.
Sun comes out, AC goes on, Sun goes in AC goes off.
Re: The other alternative...
Where I live we only need the aircon for about 3 weeks each summer. I still want my solar panels to work for the other 49 weeks, and I still want them to feed into the grid when I'm at work and (almost) everything in my house is turned off.
@ Tony Reeves 1
I sit corrected. Having googled and read a bit I have found that your are right about the local area transformer working both ways. Even so, there are limits to how much PV power can be fed into the system, and the limits can be significant... I found the following IEA report helpful:
Re: The other alternative...
Yes if you have enough PV to run your house.
But in Texas/Arizona/Ca etc most of the power demand is for AC, if you cut out all the cost and efficiency losses of power converters, safety cut-outs,feed-in tarrifs etc you could make a cheap and efficient enough system for everyone to use.
Warning ! Critical jargon failure
What on earth are CSIRO on about ? You can't use 'Cloud(tm)' to refer to atmospheric condensation. That's so last millenium.
Its good to see an article with serious discussion about solar, and raising issues from a reputable scientific body. Its fantastic that solar has gotten past the point of "should we have it at all" in australia and reached "how to make it work better". This is whats needed from here.
Where is the satellite data?
They criticise existing studies for being anecdotal, and then go on to use data coming from a few PV installations, with many graphs showing a single plant output over a single cloudy day. They say the intermittency depends on the shapes of the clouds and how fast the wind blows them, so why not analyse satellite data? Chapter 8.5 complains about the lack of satellite data at a 1s time resolution, but surely if you know how sharp the edge of the cloud is, and how fast it is moving, you can make a guess at the time series at a point on the ground.
If we paid the same price for panels here
as they seem to elsewhere ( its about 1/4 in India) we'd have the financial incentives to look at short term storage methods which might just involve hydrogen storage at the local 'petrol' station.
The suns not shining here today but I reckon my next doors wind turbines are making him feel like a reformed banker!
What about at night then? I wasn't aware that australia covered half the planet.
What a bunch of hypocrites!
CSIRO, usually respected has done a NoTW with this publication IMNSHO.
They sit in a country BBQ'd by sunlight that has done SFA to use the power of the Sun.
Solar power is a complete and utter joke in Oz, in the years we lived there and did quite a bit of Bush travel, we never once saw any Solar arrays, etc and it's a right shocker that they now put forward this position.
Rock, Glass Houses, Pot-kettle-Black all spring to mind.
Oz should lead the 3rd world with use of Solar, instead then bury their heads in the sand.
Good article as usual, Richard - thanks !
C. annedmeat may be correct in that Oz hasn't precisely lead the world in the use of what is called «solar energy» - hardly surprising given the size and distribution of Australia's «energy resources» (apologies for the scare quotes ; energy is a vexed topic) - but this report (I've read the description in the link, not the whole 198-page bible) would seem to indicate that the country (or at least CSIRO) is beginning to realise that «solar», not least in a climate like that of Australia, might have a lot going for it, but that it while it may, indeed, come down like manna from heaven, it still has to be managed. Encouraging - and it's a pleasure to have some positive news in these latter days....
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