Is the installation of solar energy collection in houses just a big have by the installation companies.

yobarr · Guru

Is the installation of solar energy collection in houses just a big have by the installation companies.

Peter_n_Margaret · Guru

Yep, energy is converted from one form to another on a regular basis.
Seen by the solar panel as radiation, converted to electrical energy, transported to a battery and converted to chemical energy or to a pump (which uses power) to convert the energy into potential (height) in a pumped storage dam which when released is converted back to electrical energy again. biggrin confuse

Unless the economics of size become a financial incentive to install a larger system, a small system will give a better return on a limited investment that a large one because more of the total energy produced will offset ex grid power than would be the case with a larger system.

"Power shifting" can make a significant difference to the returns. Run the dishwasher and the washing machine and charge the EV when the solar is collecting more than you are using, rather than at other times of the day.

Cheers,

Peter

iana · Guru

So going back to my question, "and when the power authorities place these limits, are we talking about 2kw of possible solar panel output, or is it 2kw from the inverter into the grid?", can the panel output be limited so that these limits can't be exceeded. I ask this because of the amount of shading over the roof by a large tree, I was going to send up the drone and take some pictures, seems a bit pointless now.

Peter_n_Margaret · Guru

They are still "testing the water".
The discussion has been to limit export to the grid and charge a premium for export at some times of the day.

First problem is that the grid controllers are 20 years out of date with their thinking. They are used to matching production with demand and have no concept of "inventory". This is why the new "big" batteries are making a killing, by being able to soak up cheap power when renewables are abundant and almost free and to then sell that energy at top dollar when demand jumps suddenly and the coal powered dinosaurs are still working out how to fix it. Victoria effectively paid for the big battery in SA this way.
Renewables need a paradigm shift in thinking and control. They need to think about matching demand to output instead of the other way around. If there is excess energy available, they need to switch on big power hungry things like desal plants and pumps to fill hydro storage dams (like Snowy 2) which become the inventory to make extra power available in times of low renewable output.
We will also see the production of hydrogen using excess renewables and that will become the fuel of choice for heavy transport, ships and aircraft. There is already a 30kWh hydrogen "battery" that is on the market that could replace LA and Lithium for homes and businesses.
Cheers,
Peter

Aus-Kiwi · Guru

Plus the batteries store electricity as DC . Not really efficient!

Buzz Lightbulb · Guru

We installed solar panels to help save the planet. We have lower energy bills as a side effect.

erad · Guru

I have to two solar arrays on my roof - one about 10 years old and another about 4 years old. They are 3.2 kW and 4.8 kW respectively nominal capacity, but they average only about 70% of the nominal rated output. Two inverters feed into the back of the electricity meter. I started looking into Solar Hot Water. One salesman suggested that I connect the existing solar panels to the hot water system. He was saying it was the most efficient way to heat the water. When I pointed out to him that to get 3 kW of electricity from the sun requires about 12 x 250 watt panels, and that occupies an area of about 30 sq m. A direct solar hot water system has about 4 sq m of solar panels. He kept insisting that this was the way to go so I told him where to go... Sadly, Solar Hot Water is not really that economical. The installed cost requires about 5 to 7 years at our current HW usage to pay back the investment, whereas the photovoltaic arrays paid back the investment within 2.5 years for us. Our installed PhotoVoltaic systems more than cover our energy consumption, but the excess production which is exported to the grid only just covers the distribution costs which are slugged on top of the energy charges.

Peter_n_Margaret · Guru

Aus-Kiwi wrote:
Plus the batteries store electricity as DC . Not really efficient!

Efficiency becomes less important as the value of the energy decreases.

If the energy is free, even a 10% efficiency to convert energy to a useful purpose that would otherwise be wasted is a good deal.

Cheers,

Peter

Greg 1 · Guru

Hi yobarr The feed in changes regularly and doesn't have a huge affect on our bill as we use most of what we generate and what does go back in the grid is pulled out at night. Comes of having only a 3kw system. HW system is a Rinnai gas instantaneous which is terrific. Threw the useless solar HWS off the roof years ago. It was costing me money what with leaking panels every couple of years and a booster element every year. The water quality where we are is not flash. But the solar power system has proven it's worth but just needs upgrading.

yobarr · Guru

Greg 1 wrote:
Hi yobarr The feed in changes regularly and doesn't have a huge affect on our bill as we use most of what we generate and what does go back in the grid is pulled out at night. Comes of having only a 3kw system. HW system is a Rinnai gas instantaneous which is terrific. Threw the useless solar HWS off the roof years ago. It was costing me money what with leaking panels every couple of years and a booster element every year. The water quality where we are is not flash. But the solar power system has proven it's worth but just needs upgrading.

Great results Greg! Good to see that you have realised that Solar HW is a waste of money. Beware of problems associated with "upgrades" of your Solar system, as you are likely to be "misled". Upgrades are generally a waste of time,with a complete replacement being preferable.Happy to explain why if you wish,but I can only advise you to be VERY careful.Assuming your property is single phase,around 6.5kw is generally regarded as your limit.Cheers

yobarr · Guru

erad wrote:
I have to two solar arrays on my roof - one about 10 years old and another about 4 years old. They are 3.2 kW and 4.8 kW respectively nominal capacity, but they average only about 70% of the nominal rated output. Two inverters feed into the back of the electricity meter. I started looking into Solar Hot Water. One salesman suggested that I connect the existing solar panels to the hot water system. He was saying it was the most efficient way to heat the water. When I pointed out to him that to get 3 kW of electricity from the sun requires about 12 x 250 watt panels, and that occupies an area of about 30 sq m. A direct solar hot water system has about 4 sq m of solar panels. He kept insisting that this was the way to go so I told him where to go... Sadly, Solar Hot Water is not really that economical. The installed cost requires about 5 to 7 years at our current HW usage to pay back the investment, whereas the photovoltaic arrays paid back the investment within 2.5 years for us. Our installed PhotoVoltaic systems more than cover our energy consumption, but the excess production which is exported to the grid only just covers the distribution costs which are slugged on top of the energy charges.

Hi RobertI would be most interested to learn how you can run two inverters totalling 8kw,unless,of course,you are 3 phase. Seems that you have been talking to clowns about Solar Hot water,as it is an absolute waste of roof space.Assuming the property has Solar electricity,any wise person would connect all household supply to one meter,and put a Hot Water timer to the HW system.All HW is then 'free".Unlike Solar electricity,Solar HW works on heat,so in the summer,when you don't need it,it works very well! Unfortunately,in winter,it is next to useless and regularly requires boosting.Another con-job.If you insist on having Solar HW,evacuated tubing is the ONLY way to go.Apricus is a good brand.And if your Solar export "only just covers" the distribution costs,you are exporting only 8kw/day.My system exports 28kw/day AFTER my usage,with 3ACs etc.Cheers

Peter_n_Margaret · Guru

We have had solar hot water for almost 10 years.
It supplies us with 100% of our hot water requirements for about 6 months of each year (we turn the power off completely) and a proportion for the rest of the year (when we are often not home anyway).
Cheers,
Peter

yobarr · Guru

Peter_n_Margaret wrote:
We have had solar hot water for almost 10 years.
It supplies us with 100% of our hot water requirements for about 6 months of each year (we turn the power off completely) and a proportion for the rest of the year (when we are often not home anyway).
Cheers,
Peter

Hi Peterthis is exactly what I have been saying.If you have Solar panels,you are waaay better to run the HW off them,as it all is free,and you haven't wasted $3000-$7000 on something which MAY provide 50% of your HW requirements.Con-job,unless you install an evacuated tubing system.Sorry,

.

-- Edited by yobarr on Tuesday 4th of May 2021 01:57:26 AM

Peter_n_Margaret · Guru

I have no idea what you are trying to say Yobarr.
Our solar HWS has been providing us most of our hot water for 5 years longer than we have had PV. None of our hot water is heated with PV. That % which the HWS solar does not heat is heated with off peak grid power. It paid for itself many years ago.

If I did anything to change it, it would be to add one or 2 evacuated tubes to broaden its effective "season".
Cheers,
Peter

yobarr · Guru

Peter_n_Margaret wrote:
I have no idea what you are trying to say Yobarr.
Our solar HWS has been providing us most of our hot water for 5 years longer than we have had PV. None of our hot water is heated with PV. That % which the HWS solar does not heat is heated with off peak grid power. It paid for itself many years ago.
If I did anything to change it, it would be to add one or 2 evacuated tubes to broaden its effective "season".
Cheers,
Peter

Hi Peter. What I am saying is that it is absolutely pointless forking out $3000-$7000 for a dedicated solar hot water system when you would be far better off running your hot water system directly off your solar electricity supply at next to no cost.The average household uses around 4kw/day on hot water,which means that 4kw/day is not exported at maybe 7c/kw.Therefore, your HW has cost you less than 30 cents/day,and is 100% reliable. Recouping only $3000 at 30 cents/day would take 10,000 days,or 27 years. And you still would have the inherent unreliability of a panel-based Solar HW system,which is essentially a con-job.Cheers

-- Edited by yobarr on Monday 3rd of May 2021 08:19:32 PM

Peter_n_Margaret · Guru

yobarr wrote:

And you still would have the inherent unreliability of a panel-based Solar HW system,which is essentially a con-job.Cheers

I suggest that a panel based solar HWS is no more or less reliable than PV, certainly ours is not and the only part that is "dedicated" are the 2 absorption panels and a circulation pump. The rest is common to any storage HWS, so $3,000 to $7,000 is not reality.

And if we went that way, we would loose our access to off peak power, so if the sun did not shine (as is the case from time to time) the cost of heating by grid power would double. We would also need some smarts to switch on the HWS when the PV was excess to our current use. Another cost and complication that we don't currently need or have.

Cheers,

Peter

yobarr · Guru

Peter_n_Margaret wrote:
yobarr wrote:

And you still would have the inherent unreliability of a panel-based Solar HW system,which is essentially a con-job.Cheers
I suggest that a panel based solar HWS is no more or less reliable than PV, certainly ours is not and the only part that is "dedicated" are the 2 absorption panels and a circulation pump. The rest is common to any storage HWS, so $3,000 to $7,000 is not reality.
And if we went that way, we would loose our access to off peak power, so if the sun did not shine (as is the case from time to time) the cost of heating by grid power would double. We would also need some smarts to switch on the HWS when the PV was excess to our current use. Another cost and complication that we don't currently need or have.
Cheers,
Peter

Hi Petertomorrow I will find time to correct your misunderstandings.Solar PV and solar HW are two totally different processes.Cheers

Warren-Pat_01 · Guru

G'day Ian,
We installed a 1.7Kw system just after TC Yasi in 2011. With the State Govt's generous feed in tariff of 44c & considering panels then were so much more expensive, I felt the paying $8500 was what we could afford. It came with a 2Kw inverter. By reducing our power usage & not leaving the fridge & freezer on while we were away for longer periods (6-8 weejs), we mostly had a credit on our power bill.

But then in 5 years I had a major drama & luckily a neighbor a few doors down smelt it. Our roof was on fire! Thanks to Mr. Rudd & his shonky sellers, installers!! On both occasions (the cyclone & the fire), Pat was away in Toowoomba!

Long story cut short, the roof was replaced & 2Kw panels were installed. Sometimes now we leave the freezer on but we haven't had to pay for our power. We have an ordinary HWS but we turn that off when we're not here.

Ian, we live in Townsville which gets a lot more sun than a lot of southern places. My 2Kw system supplies about the same as my brother's 5Kw system in NE Victoria. If I had a bigger system, I would consider adding a battery now.

iana · Guru

Thankyou Warren for your reply, however now the buy back rate is 3c per kw until 3pm and 10c per kw after 3pm. That's a big difference to 44c/kw. In all of this know body has commented on the file I posted, nor have they mentioned that the electricity companies are looking at fitting cut-off switches to the inverters to shut down your supply to stop system over loading. Its all about the existing wiring on the poles unable to cope with the load.

Aus-Kiwi · Guru

Peter_n_Margaret wrote:
Aus-Kiwi wrote:
Plus the batteries store electricity as DC . Not really efficient!
Efficiency becomes less important as the value of the energy decreases.
If the energy is free, even a 10% efficiency to convert energy to a useful purpose that would otherwise be wasted is a good deal.
Cheers,
Peter

Correct but how much are the batteries ? $10k with 10% efficiency ? No thanks . Besides I dont use too much when the sun goes down these days !

Aus-Kiwi · Guru

iana wrote:
Thankyou Warren for your reply, however now the buy back rate is 3c per kw until 3pm and 10c per kw after 3pm. That's a big difference to 44c/kw. In all of this know body has commented on the file I posted, nor have they mentioned that the electricity companies are looking at fitting cut-off switches to the inverters to shut down your supply to stop system over loading. Its all about the existing wiring on the poles unable to cope with the load.

Not quite true . its About voltage control .Higher voltage actually makes it easier on mains . Its the voltage stability / control adjustment at the transformers . They need more modern system .

yobarr · Guru

Aus-Kiwi wrote:
Peter_n_Margaret wrote:
Aus-Kiwi wrote:
Plus the batteries store electricity as DC . Not really efficient!
Efficiency becomes less important as the value of the energy decreases.
If the energy is free, even a 10% efficiency to convert energy to a useful purpose that would otherwise be wasted is a good deal.
Cheers,Peter
Correct but how much are the batteries ? $10k with 10% efficiency ? No thanks . Besides I dont use too much when the sun goes down these days !

Batteries are a con-job.Installing a GOOD Solar system will eliminate the total bill of most homes.The average household uses around 18-20kw/day, but I have seen consumption as low as 4kw/day,and as high as 188kw/day,in a family home.Even on single phase,which covers the vast majority of homes,it is possible to install a Solar system that will collect (generate) well over 40kw/day AVERAGE.In The Manning Council area I know of a system that has some panels North East and some panels South West,that is still averaging 38kw/day over the last year.There were options to get around having the panels South West,but this fella was happy to take the easy (cheaper!) way out.VERY few houses would use anywhere near what this system produces,but the owner can do what he likes,running welders (plural),ACs and his HW on T11.Batteries are generally a waste of space, although they are great in the back of beyond when there is no mains supply.Cheers

-- Edited by yobarr on Tuesday 4th of May 2021 01:01:10 PM

yobarr · Guru

Aus-Kiwi wrote:
iana wrote:
Thankyou Warren for your reply, however now the buy back rate is 3c per kw until 3pm and 10c per kw after 3pm. That's a big difference to 44c/kw. In all of this know body has commented on the file I posted, nor have they mentioned that the electricity companies are looking at fitting cut-off switches to the inverters to shut down your supply to stop system over loading. Its all about the existing wiring on the poles unable to cope with the load.
Not quite true . its About voltage control .Higher voltage actually makes it easier on mains . Its the voltage stability / control adjustment at the transformers . They need more modern system .

Hi Graeme ... as usual,you are correct here,but Ian has been fed so much rubbish that it is proving difficult to help him.C'est la vie.Cheers

Peter_n_Margaret · Guru

yobarr wrote:

Hi Petertomorrow I will find time to correct your misunderstandings.Solar PV and solar HW are two totally different processes.Cheers

I do understand how they work yobar. biggrin And they do both work. blankstare

The flat plate solar hot water collector was actually dramatically improved by a small company in Adelaide named Beasley Industries and I did some contract design work for them in the early '80s, so I do know a bit about flat plate solar collectors. smile

The practical development of selective surface coatings by Beasley Industries in conjunction with CSIRO gave Australian manufactures a technological advantage over those overseas, enabling them to export systems and components and to set up licence agreements in a number of countries including India, Japan, Kenya and New Zealand.

Australian Inventions and Discoveries - Page 3 - Postage Stamp Chat Board & Stamp Forum (stampboards.com)

Cheers,

Peter

Aus-Kiwi · Guru

My son has solar HOT water with gas as back up . 300l storage . He pulls the elect switch off most the year so its 100% solar . Only 2 months through winter he needs to turn on gas igniter . Hes had it over 10 years . In that time he has only had to replace the solar water pump that circulates hot water through solar to tank . This is a tube type system !! I think its the brand or type which helps here !! Or bad servicing !!

iana · Guru

yobarr wrote:
Hi Graeme ... as usual,you are correct here,but Ian has been fed so much rubbish that it is proving difficult to help him.C'est la vie.Cheers

Yobarr would you please quote and explain the misinformation (rubbish) that I have been fed!

Bicyclecamper · Guru

I think if you are wanting to put on a system, I would replace all your appliances with 4 stars or greater, leds in lights, and you can get a unit( don't know the name of it) that helps your system to run your hot water heater, or do as we have done put the offpeak on a timer so, you don't need the water heater running all night. Our winter usage is 5kw a day, and our summer is 7 kw a day. This is with %50 usage of our invertor aircond as well. It can be done. The other thing we did was do a deal with Origin, for 2 years with the option of another 2 years. Have been on this deal for 4 years so far and have just signed for another 2 years, where we get paid 11 cents a KW for solar we sell, and only pay 21 cents KW for our buy in grid power. You can make a cheap system work for you with just a little bit of effort. And it will end up working for you and be cheap as well.

yobarr · Guru

Aus-Kiwi wrote:
My son has solar HOT water with gas as back up . 300l storage . He pulls the elect switch off most the year so its 100% solar . Only 2 months through winter he needs to turn on gas igniter . Hes had it over 10 years . In that time he has only had to replace the solar water pump that circulates hot water through solar to tank . This is a tube type system !! I think its the brand or type which helps here !! Or bad servicing !!

Hi Graeme ... If it's a "tube type" system,which I will assume is Evacuated Tubing,but still needs boosting,there are not enough "tubes".Many people are conned in to installing only 22 tubes,when really there should be 30. Apricus is the go. Great systems.Cheers

-- Edited by yobarr on Tuesday 4th of May 2021 08:00:41 PM

Craig1 · Guru

Ric, Origin are very selective with their " deals" then. Will not budge above 7c feed in here, or 26.5 for normal use, 13c i think for off peak hot water. At Albury NSW

iana · Guru

Yobarr, if you cannot back up your statements with facts, then its time to make a formal complaint to Cindy. Either put up or shut up!