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Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1578

Posted: 08:36am 21 Oct 2021

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Been in the news the last couple of days that An Aussie Billionaire wants to build a 125 Sq KM solar farm in the Simpson dessert to export power to Singapore. Not a new idea, it was floated last year but the cost at least of the project has since doubled. No doubt like about everything else, It will double again time it's finished or damn near it.

Currently they are talking $30 BILLION. I'd love to see the estimated RIO in that! Guarantee it will be projected over 20 years which such technology hasn't a hope in hell of achieving. I reckon 10 would be pushing it.

The green angle is all nice and heart warming but IMHO either a PR stunt that will never get off the ground or tantamount to a scam to profit from investor and no doubt Grubbermint money.

This has been tried MANY times before in the US and other places and has, to the best of my knowledge, ALWAYS resulted in failure due to the Technical and economic issues. There are some new plants of this type in china but not sure if the conditions are comparable. Desserts take more than one form.
The similar plants I am aware of that either use Heliostats ( mirrors) or panels all suffer from the same problems and have always fallen well short of their advertised outputs and been very short lived and ultimately wasteful and completely uneconomic exercises.

There are a number of problems with setting up solar farms in the dessert.

The first is dirt/ sand. Obviously plenty of that in the dessert and it does not take a lot on the surface of a panel to degrade the output substantially. Panels ( or heliostats) need to be kept clean and of course they need to be cleaned without abrading the surface of the panels which also diminishes output through reduced light transmission.

The best way to clean dust/ sand/ dirt from a panels is obviously washing but there is a bit of a problem with getting water in the dessert for that. How much water it would take to wash 125 Sq Km of panels I cannot begin to fathom even if the water were " Recycled".

Of course the PR hype is big on these types of ideas but the details scarce. No idea how many no doubt Chinese made panels this would take but easily several Million I would suggest. Something to count against our Trade balance and Benefit Chynaa's.

Second big problem as has been shown on numerous other failed ventures of this type is shading and plant growth.
When you shade large areas of dessert the moisture content goes up and plants grow. These have to be kept in check so they don't grow up and cause shading of the panels.
Second ramification of having Vegetation is animals move in to the new habitat and with an abundance of vegetation can breed and Multiply. This can cause problems with them getting into wiring and the like and birds nesting under the panels and Hunting.
Birds of course like to perch on the panels and crap on them as anyone with home panels has seen which necessitates more washing. This alone has been a big problem with reduced output in other setups and then there is the conflict with keeping the wildlife away or Culling it. Not a popular option in this day and age. Having more shade also allows other species not normally found in desserts to survive and before you know it there is a whole alteration of the ecosystem.

On a scale such as this, there is also evidence to suggest that a solar farm this size could increase at very least localised temperatures and rainfall. Being black, the panels would absorb more heat than would be normally reflected back to the atmosphere and increased localised warming. This could change air currents and create more rainfall.

That would mean less solar radiation due to clouds and of course more rain means more growth that has to be kept under control. It could also change weather patterns in areas hundreds of KM away meaning some would dry up and get far less rainfall than usual.

Of course changing the landscape on such a scale would have HUGE environmental impacts on the habitats of so much flora and Fauna which is ironic given the "sell" of these operations is " Clean Energy". This too has been illustrated everywhere these sorts of projects have been tried.

Other factors with locating panels in desserts are the High temps panels experience in the day and the thermal cycling from cold night temps. As we all know, panels are rated at a rather cool 25oC for their output. I have MANY times seen temps 10 and 20o higher than that in the middle of winter in Sydney. I have also measured panels at nearly 80oC in summer, both documented here in my many previous rantings.

Of course when My panels have been up near 80, they don't get down to near zero in that same period as they would in a dessert. I know there are calculations for falloff with elevated temps and from memory they are quite steep with increased temps.

There is also the same problem with inverters. Their self throttling is even steeper although they could be under driven to over come this but not much can be done about the panels. The panels will degrade much faster from the higher temps they are run at as well as the thermal Cycling. I have read of a lot of scrapped Dessert solar farms in as little as 5 years and a part of this was panel degradation and diminished outputs.

The project is questionably designed to mainly supply Singapore which Incidently and not widely reported, already pulled out of the deal. Maybe they could see the problems of reliable supply at the stated outputs.
I question why with Oz making such a fuss of unreliable energy and emissions targets would we first not want to use the power ourselves?

Perhaps there is something to do with the price? Far as I can calculate the MINIMUM cost of the generated power would be around 15C Kwh delivered. The current RETAIL price of power in Singapore is 17-25C US. Does not leave a lot of margin. Aus wholesale prices are around 6 c KWH. 15c+ is not cheap at all yet on the other hand, when one calculates the amount of TWH hours that's going to need to be delivered to Recoup the $30Bn cost and then make a profit over 10 Yr time scale which ould be the max ROI time on such an investment, it would seem a risky proposition.

The 15C kwhis a very CONSERVATIVE estimate based on the minimal information I can find and I also believe the real end cost with on going maintence, loan repayments etc could be as high as 60 Odd cents per Kwh. That's also based on a 20 Yr production time which I also don't think has a snowflakes chance in hell of happening.
Technology alone would see to that! The panels will either fall off too much in output or new and more efficient panels will deliver cheaper power.

This raises the question of what happens with the old panels, the many Millions of the things. Oh yes, there is always the old Recycling Crock and that is EXACTLY what this is ATM. It is a labour intensive and rather dirty process. The major product is the glass of which there is virtually no market ATM or for the forseeable future and being of the type it is, can't be melted down and reused. It's good for a percentage of road base and that's about it. Of course them many hundreds of thousands of tons of the stuff would have to be distributed far and wide to get rid of it which would be uneconomical and no doubt result in the same outcome as panels from other farms, simply pushed into a big hole to become more land fill to leach toxic elements into the environment.

I have personally found even Cheap, early panels to be very reliable but then again I have not operated or sourced any that were run in dessert conditions. I know there have been major failures with some in Tropical conditions however. It would not surprise me if there was as much as a 10% failure rate after just a few years but that's probably only a part of the problem. The labour and cost of going round finding weak or failed panels would require a substantial work crew in itself. I surmise for this reason Optimisers would be used which are both a cost and another potential and certainly not unheard of failure point.

I also heard in a report that they were looking at a battery to go with the project.
Proposed to be 36 Gwh. 200 Times the Current SA big battery. Easy to see how this project is going to cost 30Bn. I wonder how such a battery will fare in the dessert heat? Obviously made of modules but still subject to significant heat and stress.

The losses of pushing the power 4500-5000Km are said to be around 14-15%. There is also a lot of VERY deep water between Oz and Singapore which will make laying a cable problematic, hugely expensive and Costly for any repairs needed in the future.

It would be about 3000 KM to Sydney from the plant, around 2500 to Brisbane, about 3000 to Melbourne and a bit over 2000 to Adelaide. Not to mention other places nearer where there is significant mining and Smelting operations. Running an overland/ underground cable to the distribution networks and connectors for the city's would be far cheaper than 4500Km of undersea cable that is for sure.

I would bet my arse that this never sees operation and if it does, I give it 3 years before the whole idea crashes and becomes another white elephant largely funded by the Taxpayers of THIS country.

I find it stupid to even propose given the amount of real world data and experience with similar desert solar farm projects and the poor success rate they have... or have not. I have a strong feeling this is nothing but a PR stunt or as said, a legalised scam to glean money from ignorant investors or cash in on grubbermint grants.

The technical issues are significant and fundamental which are not able to be overcome with any efficiency or economy. I do grant that such an idea would create ongoing Jobs. The workforce needed to clean so many panels and maintain/ control vegetation of an area that size would be significant.

If anyone has seen anything where these technical issues have been over come on similar setups I'd be interested to see them.

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