Sunny Thoughts

Mike Hewson
Mike Hewson
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Topic 203739

I had a home visit from a solar assessment guy yesterday. A few points :

- Tesla Powerwall 2 will be available here shortly. Basically twice the storage capacity for nearly the same price. So no point in buying a version 1 now. 

- the monocrystalline panels are quite good value for money now. These are manufactured initially like you do for silicon products by drawing out a cylinder from a molten bath. Then you cut transversely to get discs. So each disc is an uninterrupted lattice to some degree of perfection ( I'm sure Peter could tell us all about that ). These are typically trimmed to give an octagonal shape for solar cells. You'll get photo-conversion efficiency from 20 - 25% depending upon etc ....

- various panel products will vary in output and efficiency, but a key parameter for a typical roof is power per area. Unless you want to entertain other setups. Remember that you already have a roof ....

- many electricity retailers are switching to two-tier billing scales, and minimising the on/off peak billing contracts. On/off peak is, say, 15c/KWh night and 28c/KWh daytime. Nothing new there. However the two tier is applied per billing period, say three months, where your first lump of energy comes at 25c/KWh and then you go to 30c/KWh thereafter. This is an integrand and not a differential scheme. When you transition from tier to tier is up to your consumption and day/night variation is irrelevant. This change is being tucked away under some marketing BS but the simple truth is that this clearly negates one special benefit to personal storage ie. buy cheaper at night, store, and use out of the batteries during the day rather pull from the grid at twice the price.

- with the right hardware ( not involving Tesla here ) one can join schemes which will give ~ 100c/KWh ( yes, one hundred cents ) back for any excess you can store. The idea is that the big generating mobs will pay for energy in lumps that are available at short notice ie. seconds to minutes. Any longer than that could be covered by the response from their big installations. From their point of view it is cheaper to quickly pull energy to cope with, say, a large arena turning all it's lights on rather than allow current drop or call upon ( even more expensive ) falling water from a hydro scheme. I think they call this 'mini-peaks' or 'burst-feed' somesuch. Anyway if you have enough storage plus the switching/control gear you too can sell this via an arrangement with some agent/wholesaler that deals direct with the big producers. NB : the agent on-sells it at rather more than 100c/KWh ..... the top cream in the market is in the under 60 second on call bursts. Which is also chancy. I won't be doing any of that but I literally never knew about this activity, hence I pass this info on.

- following on from that the big guys have twigged that someone like me could make a large profit from them doing this. For example my roof can generate, even on a cloudy day, about 20KW. After an hour I have 20KWh to sell if I store it. Hence that's $20 with these burst feed arrangements. Plus in another hour I will have another $20 worth. Of course the value of that depends on whether the need is there to drive the sale, and whoever else is playing my game too. So they are now rate limiting feedbacks into the grid ....

- for me that is locally capped at 4.6 KW per phase. The argument is technical and for the most part true and/or consistent. There is a local nuance though. In Victoria the providers are subsided to upgrade/renew hardware, they get install price plus 10% back. That's a good commercial return ( where you still own the hardware you built ) especially if you have otherwise idle construction/maintenance capacity. The intention of said scheme was to separately support infrastructure independently of the market. But I happen to know by private means that my local grid portion is fairly well 'gold plated' at present and would not likely be bothered at even five times that 4.6 KW level. The 4.6KW figure was originally derived from, and never reviewed, some worst case instances that even when it was posited only applied to a tiny fraction of the system. Particularly it is doubtful that extant hardware anywhere in the state has that as a true physical safety limit. Currently ongoing supply/connection charges go at about one for every six dollars. Interesting.

- anyway by now you may be ( correctly ) getting the impression of a proxy war hotting up b/w established vs new paradigms. I'm not taking sides here so much as pointing out that there seems to be almost no discussion at higher levels ( than connection contracts ) where the conversation ought be taking place. 

I appreciate that I am in a pleasant personal position of going off grid should I choose. Others less placed will suffer if they are left in a shrinking public market. But there are plenty way more well off than I who won't even think twice. It looks like about $12K AUD gets me a basic solar facility and for around another $20K I could go off grid for good. However $32K is still less than the stamp duty of a mere residential block of land sale ! So the economic push to disconnect will only get greater.

Cheers, Mike.

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Mike Hewson
Mike Hewson
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Two extra points :- being

Extra points :

- sorry, that was 4.6KW per phase per household/connection ( 4.6KW is 19 amps at 240V ). Currently they will buy that at ~ 8c/KWh, but with down-going tiers with volume. With a basic solar setup I might get a few dollars a day offset to my bill.

- having gold plated infrastructure doesn't stop trees falling.

- no one sells amorphous silicon anymore ( ~ 8% efficient ). Polycrystalline comes in at 15 - 18% efficiency.

- increasingly housing/property developers now include variations of solar in their product. They get economies of scale for installation and if done at build time then way less cost c/w retro-fit. There is even talk/designs of common storage for small groups of houses, say 20 houses with maybe MWh level battery nodes. Plus if the house comes with it anyway, then why not use it ? The micro-grid cometh ..... :-))

- in a few weeks I'll be getting three hard coded $$ options to look at, ranging from minimal to full autonomy. Should be an interesting read. If nothing else I'm making the sales team work hard. When leaving he politely noted that I asked rather more penetrating questions than typical ..... he totally agreed when I asserted that we are at a pretty important cusp about now. :-)

Cheers, Mike.

( edit ) I'd mentioned elsewhere and repeat here : a major Victorian power station ( coal burning ) is closing in four months time. It generates 25% of our state's power. Go on. Guess which way the prices will go. Despite seven years lead time on this closure, I think our pollies have given up on many topics and this one also ( due to their minority party connections ). So will the market decide ? Yup. I predict that the producers will respond to give counter-intuitive outcomes ( from their point of view ). In an attempt to retain market they will lose customers as per the reasoning explained here ie. ramp up the consumer benefit for disconnect while the thresholds to do so is lowering. Given that the banks consider solar upgrades in the 'home improvement loan' category, then that will finance/drive the change from the monetary side. Mortgage money is about 4% currently. There's even an installation ( tax ) rebate.

( edit ) News just in : the power unions have announced random strikes ( at the Loy Yang generators ) during the upcoming festive season to protest against the Hazelwood station closure as above. Hey ? What ? Doh ? You could not deliver a better Xmas present to the solar industry than that .... :-))

( edit ) I can't believe that happened. There I was predicting a counter-intuitive response from the power industry and bang, half an hour later .....

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Bill592
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Howdy Mike !  Interesting

Howdy Mike !

 Interesting stuff !   I wish I could move totally  'Off Grid'  myself.

Maybe someday  )

 

Bill

 

.

Chris S
Chris S
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Going green and solar was all

Going green and solar was all the rage here a few years ago. Mainly because the feed-in tariffs were generously underwritten by the government to encourage takeup. But time moved on, and cheap solar panels from the Far East dropped substantially in price, so there was a correspondent drop in the feed in tariffs. At present it takes about 17-18 years on average to get your money back from a solar installation for a domestic location. For a factory or an office block they can claim tax relief on business operating costs. Quite apart from the fact that in the Northern hemisphere in the UK sunlight is in scarce supply. Although modern panels  can generate in cloudy weather.

We all know that coal and oil fired power stations are being phased out, mainly because fossil fuels are running out, but also because of the polution and perceived global warming. There are wood pellet stations, but very inefficient. The only long term future over the next 100 years for public power generation is clean nuclear.

But the public confidence has been dented because of Chernobyl, 3 Mile Island and Fukushima. But all of those were operator error or bad design. Mankind has to learn and learn quickly how to safely manage this, before all the coal, oil, and gas has gone. Fusion or fission, hot or cold, more research has to be done.

But do bear in mind that there are two types of solar panel. One generates hot water from sunlight, the other generates electricity. The former seems to cost in better at the moment.

Waiting for Godot & salvation :-)

Why do doctors have to practice?
You'd think they'd have got it right by now

Mike Hewson
Mike Hewson
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My repay calculation ( about

My repay calculation ( about six to seven years, depending on etc ... ) is based on neither buying electricity nor selling, at any pricing level. That's what off-grid means : no transactions. This is the anti-intuitive bit for the producers as they haven't got a market plan for 'not interested'. How could they ? When the higher tariffs hit here mid '17 then more will pay attention to the topic and this logic will be as plain as daylight. :-))

The other, often forgotten side of the coin, is household energy expenditure. This is quite locale specific and thus difficult to generalise about. The main thing is to consider it all. Simple things can work very well eg. put a jumper on rather than crank up the central heating.

In the short term I predict the producers will lobby to effectively tax/regulate sunlight, to keep their gig going, as monopolies have always done when faced with radical marketplace change. For example there's a pretty hot topic in Florida about that right now ie. non-solar producers having 'great ideas' about solar power. In the longer term the inevitable will happen : human generations have only ever thought & acted in their own immediate terms. For most people a great grandchild, to meet and greet, will exist in potentia only. The DownUnda pollies don't deal with this topic much anymore due to the rapid/rabid responses it has provoked in the last few decades, and so it has become like healthcare : votes can only be lost so leave well enough alone..

Cheers, Mike.

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Mike Hewson
Mike Hewson
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FYI I have received install

FYI I have received install quotes for various options. I'll show you the top of the line one ( called the 'Autonomy System' ) :

solar_quote.jpg

This is of course in $AUD. The interesting points are :

- the choice of monocrystalline panels ( best efficiency ) on about half of my available roof area.

- 9.8KWh storage ( made by LG not Telsa ).

- the Selectronic gadget which technically qualifies as an acceptable feedback-to-grid rate limiter and thus I may choose it's upper threshold to be no higher than the utility prescribed 4.6 KW. Or whatever. I may feed none back at all. Either way with this ability in place the utility has no say about what I do on property. Plus if they don't like that they are free to disconnect me ! :-)))

- not specifically mentioned ( it is in 'Associated AC & DC Switchboard & Protection'  ) is a generator power feed-in point to the house board.

- this attracts a 10% Goods & Services Tax ( GST ).

- the 'Estimated GCS STC Deduction', a handy six grand, refers to Grid Connected Systems Small-scale Technology Certificates ie. a rebate for installation. 

- expandable in the obvious ways : more panels, more batteries.

- one could be involved with the mini-peak/burst-feed market with this gear, obviously only if you remain on-grid. This and some other scenarios is where a Tesla Powerwall ( I or II ) would blow/melt on current limits.

I'm leaning towards this one. It's a proper solution and all I need to do is find $30K .... LOL ... time for a chat with the bank.

Cheers, Mike.

( edit ) Also this option is compatible with Time Of Use contracts available with some energy retailers. The trouble is that they in turn are obliged to be constrained by the specific 'poles & wires' provider locally ( who designate the feed-in 4.6KW limit ). The curly bit is that while allegedly these are independent entities, on paper, there are common shareholdings upstream with - yes, you guessed it - clever commercial 'optimisations' applied indirectly/obtusely. At present this has not been officially viewed as either cartel-like or 'third line forcing' on the grounds of public interest or market efficiency. The typical answer is that you have to give some stability to investors. I understand that. However I'd repeat that resolving the classic shareholder/customer tug-of-war by proxy ( connection contracts, technical standards .... ) is not the way to go. Bad process.

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Chris S
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Well Mike if you have the

Well Mike if you have the roof area, and the annual sunshine, and the payback period for $A30,000 (£17,650) is 7 years it is worth thinking about I would say. The installation is 8.8 KW usable. With the washing m/c on, kettle boiling, fridges, lights etc my power meter goes up to 5KWh peak, so 8.8 is OK I guess at peak times. But without power storage facilities like night time storage radiators that charge up doing the day, you will still need the mains for night times. Is there any hot water generation there or is it all electrical?

 

 

Waiting for Godot & salvation :-)

Why do doctors have to practice?
You'd think they'd have got it right by now

Bill592
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You probably thought about

You probably thought about this but, consider having some alternate power generation for a backup.   (if totally Off-Grid )

A. a diesel (or gas) Generator

B. Maybe some small wind generators (they make some nice smaller ones)

C. If you had a stream nearby (Magic does I believe) they even make some small hydroelectric generators (Using propellers)

D. Popular mechanics had an article a few years ago about someday owning your own personal Nuke Plant Laughing

In the US way back before about 1935 - a lot of farms had a 32volt dc power system.Made by Delco - it consisted of a bank of 16 Glass cased batteries (lead acid) and a small 1.5 horsepower DC  generator to charge the system.

Of course - Nikola Tesla was smarter than Edison - which is why we are on AC today Smile

Bill

 

Mike Hewson
Mike Hewson
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We have a natural gas supply

We have a natural gas supply to the property for hot water and heating. This leaves the electricity burden largely with motors/compressors. Fridge, freezer, washer, dryer, vacuum cleaner etc. It's funny when you think about this ie. what do you really mean when you say 'off grid' ? That answer turns out to be highly specific to circumstance and therein lies the rub generally. I've decided to go for a middling solution in the interim. Basically that's the $30K system I quoted before but with a different battery type and about 2/3 of the PVs on the roof. That's a money decision not a technical one.

I think the Tesla Powerwall is going to be fine for charging Tesla cars but only for those with the roof area. I don't know how that would work for medium to high density housing where area is at a premium. The systemic concern is ongoing provision to those without favorable technical/monetary characteristics in their own personal scenario. One good option is community level shared PV. But that then acquires an extra political aspect and DownUnda at least the Green 'brand' is thoroughly trashed on other grounds, and especially in the topic of renewables. There needs to be a far more focussed/pragmatic/cooperative impetus shorn of irrelevant agendas ie. way less polly-ticking*.

Cheers, Mike.

* So my political comment here is that there should be less politics ! I hope that is OK with contributors, please advise otherwise ...... :-))

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Mike Hewson
Mike Hewson
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FWIW : Tesla's Gigafactory is

FWIW : Tesla's Gigafactory is now online and producing batteries.

Cheers, Mike.

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Mike Hewson
Mike Hewson
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Well guys, the inevitable has

Well guys, the inevitable has happened. Sunny thoughts not withstanding, we are instead getting a kitchen upgrade. :-))

As for the Hazelwood closure the inevitable is also happening. The guvment has rolled out a piece from a kindly and well remunerated boffin think-tank to say how nasty the ripoffs are from the producers, and so the guvment will have done 'everything it possibly can' ( ahem ). They missed the mark terribly though, as it was the distributors who were doing that reaping. But the average punter won't make such distinctions as it is all 'they' isn't it ? So a dog's breakfast of a public discussion awaits on that one. BTW : we are the nasty polluters, as we enjoy the lifestyle benefit from buying the electricity from the people that do it on our behalf. Thus it is not a matter best suited for the adversarial/advocacy techniques much beloved of modern public discourse ie. identity/labeling schemata won't help. Us & we are them & they. :-))

This nicely pre-empts the actual problem in May when the last electron will flow from that site. And so price regulation is hinted at with the wimpy fist in the lamington glove. This solves nothing and if anything ups the ante to sell the electricity across the border - a viewpoint strongly supported across those borders. New South Wales can never get enough at any price due to spiralling demand and South Australia can also never get enough because their wind farm investment is an epic fail.

You see there's a relatively ancient clause in constitutional law asserting that no-one, guvments included, can restrict trans-border trade. This was originally intended to inhibit monopolies within our previously separate colonies. On many occasions since parties have come to grief in the High Court ( federal ) on that one.

So the failure to replace Hazelwood capacity, a longstanding inactivity policy, will have the original desired effect. Prices will go up and shortages will happen, and this will pressure individual decisions about consumption. As originally intended. But everyone will say it is someone else's fault. Including me. LOL. :-))

Cheers, Mike.

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