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The future of energy generation and storage

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Smurf1976 said:
(well, some companies do co-operate within reason but they can't go too far or the ACCC will ping them for collusion - that being problematic in a renewable energy system where you need everyone on the same team in order for it to work reliably and efficiently).
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It's pretty sad if companies can't cooperate to give consumers the best deal.

Competition policy doesn't really work for essential services.
 
SirRumpole said:
It's pretty sad if companies can't cooperate to give consumers the best deal.

Competition policy doesn't really work for essential services.
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Once upon a time we tried to follow the principles of Maslow. Necessities of life were in the public domain and our Government supported us. But Gough Whitlam came and went too soon unfortunately.
 
I saw an advert today for a “smart hot water system”
The “solahart powerstore”

https://www.solahart.com.au/products/battery-storage/solahart-powerstore/

Rather than sending your excess solar electricity to the grid, this system first uses it to heat your hot water tank, it monitors your solar generation and household consumption, increases or decreases the rate it heats your water so it is not drawing from the grid and can accept any excess power you produces as you production and demand fluctuate.
 
Smurf1976 said:
Well how about that.

I've just spent the past few hours confirming exactly what equipment to get under this scheme....
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What do you think about smart hot water systems, that work similar to batteries, eg automatically switching on and off accepting you excess generation throughout the day as you produce it.
 
Value Collector said:
What do you think about smart hot water systems, that work similar to batteries, eg automatically switching on and off accepting you excess generation throughout the day as you produce it.
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As a technical concept it's a great idea beaten only by network switching of the same loads (in the Australian context only Qld, NSW and a few small isolated systems eg King Island have the infrastructure set up to do that).

There's a lot to love technically about having loads which automatically respond to solar generation. The only thing better is the ability to directly control the loads in response to all system conditions but doing it automatically in response to solar is the next best thing.

As a consumer financial decision I'll sound a big word of caution however and say that the concept won't meet consumers' expectations of lowering bills in many, perhaps most, cases. That's the short answer, what follows below is the detail if you want it.

The concept is to take electricity that would be fed into the grid during daytime and use that to heat water, thus avoiding the cost of some other means of heating the water (eg off-peak electricity).

Now where the problem arises is when you do the maths.

*The energy you divert has a cost of lost income, that being at whatever feed-in tariff (FIT) rate you receive.

*The energy you are replacing will in the vast majority of cases be off-peak electricity if the same water heater is used or alternatively gas if we're talking about a new system replacing something existing.

Now the trouble is that for a lot of Australians their FIT rate will be very similar to what they could buy off-peak electricity for meaning that there is nothing to be saved. That is the first problem.

The second problem is that every commercially available product I've seen which does this requires that either a 24/7 electricity supply is connected and used as the booster, or that if an off-peak supply is connected the booster be manually operated. I've yet to see any "off the shelf" product which is able to automatically boost using a separately metered off-peak supply.

If you have time of use (TOU) metering with everything through the one meter (fairly common in Vic and NSW, exists in other states with the notable exception of SA), or if you live in a place where there's only one flat rate tariff (NT and a large portion of consumers in WA and remote towns not on the main grid on other states) that won't matter in the slightest since you'll incur no cost penalty, compared to how you'd otherwise heat the water, when boosting.

If however you have a separately metered supply for water heating, which is almost always the case in Qld, NSW, ACT, Tas and SA and also for many in Vic, then even a small amount of boosting at peak rates will blow any savings to pieces. There's the big flaw.

As an example, suppose that:

FIT = 20 cents / kWh
Off=peak price = 24 cents / kWh
Continuous tariff price = 42 cents / kWh.

Those are the actual prices, rounded to the nearest cent, charged by a major ASX listed retailer in SA.

Now you're likely to heat somewhere around 70% of your water using the solar in SA's climate. Yes everyone knows that SA gets seriously hot and has lots of sun, it's 1am and outside my house it's 29.5 degrees right now, but there are also quite a few days with no sun at all and those just happen to be mostly in Winter when the incoming water is coldest thus requiring the most heating.

So let's do the maths.

70% at 20 cents and 30% at the continuous tariff of 42 cents = 26.6 cents per kWh on average.

So you'll be paying ~11% more to heat your water than if you just stuck to good ole off-peak from the grid. That also doesn't require purchasing an approximately $1000 device to control the water heater, plus installation by a licensed electrician, or alternatively a "smart" water heater at whatever that costs.

Now you are probably thinking why not just rig it up to boost using the off-peak?

Technically that can be done but I've yet to come across anything "off the shelf" which does it. Whilst you could wire it up quite easily to work that way, any electrician is going to be more than a tad reluctant to be doing so given issues of compliance with Australian Standards, electricity distributor standards and the consequences if anything goes wrong given that the installation contravenes manufacturer's instructions (versus the law which specifically requires electricians to adhere to the manufacturer's instructions). Doing this is commonly referred to in the industry as the MacGuyver approach to heating water (a reference to a well known 1980's TV program for those not familiar) and for good reason. It'll work but it's a lot of bits stuck together.

But let's suppose you do go down that track. Divert the solar and boost with off-peak.

70% of water heated from electricity that you'd otherwise receive the FIT for and 30% heated from the off-peak grid supply = you'll save 11.67% using the prices I quoted from a major retailer.

So, a ~12% saving that'll cost you ~$1000 for equipment plus an electrician's labour charges and some minor materials to install (if you can find anyone willing to set it up that way). Hmm....

Just in case that didn't convince you, it gets even worse if you just ask the electricity retailer for a better price. Sign up with Origin, take all the discounts for direct debit, not receiving paper bills etc and you'll have an off-peak water heating rate that is less than the FIT. In that case diverting solar into the hot water would be completely pointless.

In contrast a decent quality heat pump will actually save energy as such and we're talking a 70- 80% saving there. The good ones will work just fine on off-peak supply also so there's no issue with using less but paying more for it.

At a suitable property a solar water heater will save 50 - 100% of the energy otherwise used and if correctly designed will boost with off-peak electricity or alternatively gas. So no costly peak rate power involved there.

For others gas can still be worth a look. It's a bit out of fashion at the moment but depending on circumstances I wouldn't write it off by any means. Really comes down to the house design and so on - there are situations where gas wins simply because it's physically more practical.

Overall, there are circumstances where the idea of diverting solar to heat water can work. If you're on a flat rate for all electricity consumed and the FIT is considerably lower than the price you pay for power from the grid is one scenario. If you've got a truly massive solar system and will never need to boost the hot water is another. If you've got Time Of Use metering and a low FIT that's another. For the majority though the finances aren't that great.

Alternative options sort-of achieving the same end result:

Tasmania - Tariff 93 is a Time Of Use (TOU) product for all your household electricity including solar feed-in. As part of that you get off-peak rates weekdays 10am - 4pm and 9pm - 7am as well as all weekend. Now just use a simple timer to heat the water 10am - 4pm and your solar will automatically be the priority source with any additional energy always charged at the off-peak rate. Done!

SA - Not available yet but there's a definite thought about doing something which will look awfully like the Tasmanian approach. Times for the cheap rate are likely to include 10am - 3pm and 1am - 6am. Just heat the water 10am - 3pm and you've got your solar being used as priority and backup at the off-peak rate. Nothign fancy required, just any old electric water heater and a simple timer. Note however this doesn't exist yet, it's just at the planning stages.

SA - If you want a battery then AGL still has some heavily subsidised ones available including Tesla Powerwall 2 and LG systems. There are some conditions, like needing to sign up with AGL for your electricity and participate in their Virtual Power Plant program, but they're offering huge discounts on normal pricing so it may interest some. This is an AGL scheme.

SA - The state government has a battery subsidy scheme available, the rate being $500 per kWh for most and $600 per kWh of capacity for concession holders with a maximum payment of $6000. At present it only applies to systems manufactured in SA, which gives you a choice of Sonnen products only, but next year it becomes broader and others will be available.

Vic - I'm not sure of the exact details but the state government is handing out $ for solar in a pretty big way. At present Vic has a considerably lower % of homes with solar as compared to Qld or SA so they could add quite a lot before any real technical issues emerge (but go too far and they sure will). :2twocents
 
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sptrawler said:
Yes, I was reading RCR Tomlinson are putting in a few solar plants for them. Seems one of the farms is going to cost RCR dollars with miss quoting and running over budget.
But they do sound like decent installations.
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That was back in August, sounds like things have got worse since then, I suppose funding these projects is a real issue.
Also getting people to work in the middle of nowhere, is becomming harder and harder.

https://reneweconomy.com.au/turmoil...-rcr-stock-suspended-on-earnings-fears-60418/
 
SirRumpole said:
Maybe Smurf can comment on this and if its a big deal or not.
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There are technical issues with maintaining stable voltages certainly but the claims being made in that link are a huge exaggeration of the consequences.

Yes the kettle will boil faster at higher voltage but that just means it turns off sooner. Increase in energy consumption = zero.

Pretty much the same scenario for a lot of things whilst for any modern electronics there will be a switchmode power supply inside which takes care of that.

What will actually use more energy at a higher voltage?

Incandescent, halogen or old (but not modern) fluoro lights. Most likely you won't have many of these running when voltages are highest though (generally around midday and between midnight and dawn).

Heating elements that are manually turned on for a set time period, for example a heater in a bathroom, and which don't have a thermostat.

Older or very simple electronics with linear power supplies. Eg clock radios.

So not that much really. It's not going to add some huge amount to your bill, we're talking minor amounts here.

So far as controlling it is concerned, it's basic physics that if the transformer puts out exactly 230V then the further down the line you go, and the more load is applied, the more that voltage will shift to something else.

Since load will result in the voltage falling, traditionally the approach was always to send out something a bit higher than the standard which used to be 240V and is now 230V. Send out 250 and those at the end of the line will get something between 230 and 240 depending on load at the time with those closer to the transformer getting something higher (but not higher than what the transformer is sending out).

Solar has complicated all that since households feeding into the grid will push the voltage on the line up rather than down.

Now where the problem arises is what voltage should the transformer be sending out?

Use 250 and you'll get a lot of complaints about solar inverters shutting down due to excessive voltage.

Drop it down to 230 and then you'll get complaints that houses are only getting 220 or less when it's cold and dark in winter. That doesn't work too well with appliances that were intended for 240V.

Depending on the location and how much the load varies, it might be a simple case that there is indeed somewhere in the middle which works just fine. For other places though, well there's simply no one voltage at the transformer that actually works in this scenario. Anything low enough to avoid problems during daytime from solar is too low to avoid problems in winter at 6pm and vice versa, there's literally nothing that overcomes it.

The solution obviously is to dynamically change line voltages. Yes that can be done but suffice to say that in general the infrastructure isn't in place. The grid was built for one-way traffic not two way and the increasing use of solar is stretching the limits of what existing systems can cope with in some areas.

Then there are differences between states as to how "strong" the network was built in the first place and thus how well it can cope with solar being added and power flow now being in the opposite direction.

The situation there is the predictable one. Any problems in Tasmania will be isolated instances but there are known widespread issues in SA including across suburban Adelaide.

Part of the issue there is that even before solar, SA had one of the most variable electrical loads of anywhere in the world with weather being the primary influence. Plenty of mild days where no heating or cooling is required but then there's those days well into the 40's and likewise nights well down into single figures. So that gives a lot of variation. Now add solar on top of that and the situation is that load in the suburbs goes pretty close to zero now on a mild day but the peak hasn't changed much when it's hot.

So there are issues yes and if you aren't getting the expected output from a solar system then I strongly recommend that the mains voltage be investigated (by an electrician unless you're competent to safely measure it yourself) but as a rule no, you don't need to buy someone's overpriced device to control your supply voltage and it most certainly won't save you a fortune in any normal residential situation.

The ABC ought to have done some more research in my view since what they've done basically amounts to an advertorial for a commercially available product which the majority of consumers would gain no benefit from. :2twocents
 
sptrawler said:
Well Smurph's predictions, appear to be just around the corner, at least it should start and bring some reality into the debate.
It is o.k saying we want all these Power Stations shut down, but when people are sitting in the dark sweltering, it gives them an opportunity to consider the reality.

https://thewest.com.au/business/energy/a-summer-of-blackouts-bc-5967600368001
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Government paralysis. The Libs don't want to upset the power companies so they sit on their hands and try and pretend that everything is OK.

I really don't know if Labor can do any better, but I'm willing to take the chance that they will at least try.
 
SirRumpole said:
Government paralysis. The Libs don't want to upset the power companies so they sit on their hands and try and pretend that everything is OK.

I really don't know if Labor can do any better, but I'm willing to take the chance that they will at least try.
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Well it certainly will be entertaining watching, that is of course if you live in W.A, or Tasmania.
 
sptrawler said:
Well it certainly will be entertaining watching, that is of course if you live in W.A, or Tasmania.
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Vic, SA, NSW/ACT in that order is where the problems are with Vic being considerably worse than the other two.

For the other states they'd need something to go horribly wrong to end up in the same situation. Not impossible but unlikely in practice.

There are of course financial impacts for relevant companies, some of which are listed, in all of this. :2twocents
 

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