[Aussie Keith]

I thought I would revisit the topic again now there's now a bit over a years worth of data captured. Just to revisit, this is a 5kW system with two monitoring solutions attached. One is PV only at the inverter, the other is capturing PV output at the meter box as well as the grid input at the meter box and as a result gives way more information. Data quality is good and the analysis is very interesting - if you like that sort of thing.

Those that are interested can see the complete stats from the second monitoring system here: http://pvoutput.org/statistic.jsp?id=22783&sid=20672

The lifetime information is here (earlier monitoring system): http://pvoutput.org/statistic.jsp?id=22783&sid=25566 but does not factor in consumption.

What it shows is that the modelling I did was not even close. Its almost impossible to factor in weather which affects generation efficiency quite substantially.

Looking at this chart: http://pvoutput.org/aggregate.jsp?id=22783&sid=20672&t=w you can see that its definitely saving money, but the rebate is now minimal at the wholesale generation rate of 6c/kWh compared to the massive fit paid previously. Nonetheless its still providing significant savings, especially considering we run ac 24/7 and the comms gear runs 24/7 as well.

That's probably all I have to say about it.  I hope the information is of use to someone.

[Paolo5]

but the rebate is now minimal at the wholesale generation rate of 6c/kWh compared to the massive fit paid previously.

Wouldn't you think that our government would be behind this (after infrastructure) free energy...over the long haul. Australia is capable of generating so much energy from the sun. 

I am getting 20c/kWh from Origin, which makes things that much better.

[plasticphyte]

I'm thankful that our system is still on the old QLD rebate (48c IIRC). Although I don't have any monitoring like yours Keith.

I would really like to see governments do more work in getting solar power units of at least 2-4kW as a mandatory requirement for new homes built after a certain date, along with 5,000L water tanks.

I'd really like to see more solar setups in urban environments that utilise battery banks, and I'd love to see a migration away from 240v electrical goods so that the only 240v appliances were just those that absolutely had to be.

Would certainly be a big step towards being smarter with our (societies) power consumption.

[beerman]

I'm thankful that our system is still on the old QLD rebate (48c IIRC). Although I don't have any monitoring like yours Keith.

I would really like to see governments do more work in getting solar power units of at least 2-4kW as a mandatory requirement for new homes built after a certain date, along with 5,000L water tanks.

I'd really like to see more solar setups in urban environments that utilise battery banks, and I'd love to see a migration away from 240v electrical goods so that the only 240v appliances were just those that absolutely had to be.

Would certainly be a big step towards being smarter with our (societies) power consumption.

Would also be a big step to being self sufficient in the event of a big weather event. Once batteries are cheap enough, solar will reduce the severity of power out issues as once the event is over, the sun will come out and all those with hybrid power will have a power supply again. With batteries available to be charged before the event, a household could have a source of power for the majority of any outage.

[Dazzler]

Still loving our relatively small 3.8 KW system (One of the best things we ever did) With Evacuated tube Solar hot water added about 6 months ago looks like we will still come out about square for the year despite having a power hungry boarder for the last few months!   

[mjt57]

and I'd love to see a migration away from 240v electrical goods so that the only 240v appliances were just those that absolutely had to be.

Er, why?

[beerman]

Oh and got my summer bill the other week..... $80 credit.....$680 for the year so far (I think it runs on the financial year?)

[Dazzler]

and I'd love to see a migration away from 240v electrical goods so that the only 240v appliances were just those that absolutely had to be.

Er, why?

 

[Aussie Keith]

Oh and got my summer bill the other week..... $80 credit.....$680 for the year so far (I think it runs on the financial year?)

Nice work for you and those that got in on time. Jealous. 

I'll take what I can get though. Looking into storage solutions, the issue being cost and space. Lithium ion batteries are now used instead of Pb based batteries which is good for a range of reasons but you need to put them somewhere. None of this is insurmountable but right now its still too expensive at the moment to be a viable option. That will change in time and then it is possible to be largely neutral energy wise. I actually put more into the grid than I take out but the difference is 24 cents in favour of the supplier.

http://www.smartroof.be/documenten/Smart%20Independent%20Energy%20Solutions.pdf

[Dazzler]

I didn't read the PDF yet Keith, but the Founder of Tesla Motor cars is talking about making very efficient storage batteries for solar in the near future. By the time my 28c FIT rate  runs out in about 3 and a half years it might be an option.. 

[beerman]

I've got a fair bit of time for the batteries to come on before my government legislated goodness runs out (0.52c).



 

[Surferdude]

I've got a fair bit of time for the batteries to come on before my government legislated goodness runs out (0.52c).

Me too. 

[Aughy]

This guy has the answer FREE FUEL FOR HOME & CAR!! And the beauty of burning hydrogen is the exhaust fumes are WATER!
Solar hydrogen home Michael Strizki - YouTube

[mjt57]

I'll take what I can get though. Looking into storage solutions, the issue being cost and space. Lithium ion batteries are now used instead of Pb based batteries which is good for a range of reasons but you need to put them somewhere.

What about up in the roof space? Are there any issues doing that?

[Phil №❶]

This guy has the answer FREE FUEL FOR HOME & CAR!! And the beauty of burning hydrogen is the exhaust fumes are WATER!
Solar hydrogen home Michael Strizki - YouTube

Commendable, but impractical. The cost would be in excess of the energy bill.
Our local council Hitlers wouldn't allow it.

[Aussie Keith]

I'll take what I can get though. Looking into storage solutions, the issue being cost and space. Lithium ion batteries are now used instead of Pb based batteries which is good for a range of reasons but you need to put them somewhere.

What about up in the roof space? Are there any issues doing that?

Access, heat, ventilation, fire risk and weight. It would be much better to have them stored outside at ground level in a properly insulated and ventilated firesafe cabinet. Basically the off grid storage needs to be engineered to provide the proper environment to allow for safe installation, regular inspection, and the proper temperature range for a long efficient battery working life as well as controlling any fires or similar battery disasters.  Where I live the heat in the ceiling space in summer would kill batteries in short order for a start. I have a 1400kVa UPS for comms backup  here which has 4 12V sealed lead acid batteries and despite it sitting in an air conditioned room the heat build up in the UPS and its immediate environment means the batteries only last about 2 years. You want a lot longer service life from an off grid battery pack than that, at least ten years.

Battery packs for off grid storage contain a lot of energy and can do a lot of damage if things go wrong.

Lead Acid (LA) batteries are the usual solution but they are massive, heavy, require a lot of maintenance (from first hand experience): countryside - homesteading - self-reliance - simple life

Valve-Regulated Lead Acid batteries are a better but more expensive option.

I am more interested in Lithium batteries as a storage medium:

Lithium-Ion Batteries for Off-Grid Systems | Home Power Magazine
Off-Grid Energy Australia - Batteries

Lithium-Ion batteries are becoming a viable option with the advantages (and disadvantages) noted above.

BU-502: Discharging at High and Low Temperatures ? Battery University

As I mentioned prices at present don't make it economically viable to go off grid just yet. But it will happen eventually no doubt.

[Aussie Keith]

This guy has the answer FREE FUEL FOR HOME & CAR!! And the beauty of burning hydrogen is the exhaust fumes are WATER!
Solar hydrogen home Michael Strizki - YouTube

Commendable, but impractical. The cost would be in excess of the energy bill.
Our local council Hitlers wouldn't allow it.

Good find. I have no doubt that all that tech could be scaled down for home use and made economical. I do doubt though that hydrogen storage in residential areas is likely to occur any time soon.

[beerman]

I'll take what I can get though. Looking into storage solutions, the issue being cost and space. Lithium ion batteries are now used instead of Pb based batteries which is good for a range of reasons but you need to put them somewhere.

What about up in the roof space? Are there any issues doing that?

Access, heat, ventilation, fire risk and weight. It would be much better to have them stored outside at ground level in a properly insulated and ventilated firesafe cabinet. Basically the off grid storage needs to be engineered to provide the proper environment to allow for safe installation, regular inspection, and the proper temperature range for a long efficient battery working life as well as controlling any fires or similar battery disasters.  Where I live the heat in the ceiling space in summer would kill batteries in short order for a start. I have a 1400kVa UPS for comms backup  here which has 4 12V sealed lead acid batteries and despite it sitting in an air conditioned room the heat build up in the UPS and its immediate environment means the batteries only last about 2 years. You want a lot longer service life from an off grid battery pack than that, at least ten years.

Battery packs for off grid storage contain a lot of energy and can do a lot of damage if things go wrong.

Lead Acid (LA) batteries are the usual solution but they are massive, heavy, require a lot of maintenance (from first hand experience): countryside - homesteading - self-reliance - simple life

Valve-Regulated Lead Acid batteries are a better but more expensive option.

I am more interested in Lithium batteries as a storage medium:

Lithium-Ion Batteries for Off-Grid Systems | Home Power Magazine
Off-Grid Energy Australia - Batteries

Lithium-Ion batteries are becoming a viable option with the advantages (and disadvantages) noted above.

BU-502: Discharging at High and Low Temperatures ? Battery University

As I mentioned prices at present don't make it economically viable to go off grid just yet. But it will happen eventually no doubt.

I would presume that the battery storage would ideally need to be close to the inverter and whatever controller is going to make them all sing together.

Like Dazz, I have heard that the Telsa battery factory in China has a massive over capacity. Once in production, this should see the battery price fall. Further I have read that the increased uptake of electric vehicles provides a double boost, one the use of the vehicle as a power storage unit for the household and b) the batteries once used in vehicles can be used as a battery for a solar house due to the lower demands.

Interesting times. 

[Lakes]

Am i right in thinking , it's only QLD & TAS members fitting solar panels?
also how will you dispose of the old battery's?
also i'm wondering what state has cheapest power in au?

[Phil №❶]

The problem is the FIT (Feed In Tarrif), John. It has been reduced to minimal levels making the initial outlay costs, nonviable in most cases. The solar suppliers have reduced their prices by 50% in order to keep trading, but for the owner, it's a whole new ball game in justifying even this reduced expense, in terms of recovery or profit.

We got our baby system at the highest FIT and although we could get a 2x size for the same price today, we woud be reduced to the current low FIT. Our FIT is working nicely for us. Last bill in winter / spring was $-16.00. We are completely LED lighting now and 1 waterbed permanently turned off, which should make an even further benefit. Unlike AK, we don't have the marvelous monitoring that he has, but I think we're doing ok.

[Aussie Keith]

Its true, the change in fit alters the economic arguments for solar power but not the need.

Previously the rivers of gold derived from power pumped back into the grid made it ideal for people who were hardly at home in the daytime which is most people other than Dazz. This is because most of the energy is generating $$$ at the rate of about a dollar for each 2kwh. Now you get 12 cents for the same amount of energy..

The fit is at the wholesale rate of 6c per kw/h and yet we buy at about 30c per kw/h. So what we use saves us more than what we don't use which is the opposite of the previous situation. I approve of this model by the way, but regret not having the bigger fit all the same. Anyway it makes sense to use the power hungry appliances such as the dishwasher in the daytime instead of the evening. The AC is on all day long here and so forth. This still provides us with an excess and we are roughly neutral in terms of energy use but because of the lack of storage, we are effectively paying 24c per kw/h for what we source from the grid in the evenings. Still much better than the alternative but nowhere as lucrative as before.

Looking at the graphs below you can see the usage for yesterday. You can clearly see the fluctuation in generation as it was slightly cloudy. The red line is consumption with the red filled area aggregate power. From this you can see we had an excess of energy for part of the day and this is what goes to the grid. The bottom chart shows this more clearly. In consulting with my accountant about solar, he emphatically claims it is still a great investment and to get the biggest one you can fit on the roof. It will continue to pay for itself years into the future.





Getting back to storage, our power bills are so low that storage systems would need to be very cheap indeed to be cost effective. A $2400 system if it existed would take about 3 years to pay for itself and require maintenance during that time and replacement of the batteries in about 6 years. Since they cost orders of magnitude more, its hardly a compelling business case for offline storage at present.

Frequently Asked Questions
Off-Grid Energy Australia - Autonomy Unit

[Phil №❶]

It's a pity Hydrogen is so volatile and difficult to store in usable quantities. I would love to generate the evening's power in the daytime and tell our power network supplier's, "no thanks". If I only had my own private lake and a hill, I could pump water up daily and run a water turbine at night.

[Surferdude]

Am i right in thinking , it's only QLD & TAS members fitting solar panels?
also how will you dispose of the old battery's?
also i'm wondering what state has cheapest power in au?

I have a mate in Merimbula, John. He has had solar panels for some years. Got in before the State Gov't reduced the Feed in Tariff, so he's laughing.

We get about the same annual rebate as Beerman quoted above. Only a 2.5 KW system but we installed a Solar HWS (Rheem) at the same time. That's the thing which has made the biggest difference to our bills.

[Phil №❶]

We have a baby 1.5 Kw system, Led lighting, Inverter A/C & Washing Machine, Led TV. Next will be Inverter Mwave Oven when the one we have retires. At the high FIT, we're doing ok.

[Dazzler]

Solar hot water has been better than I expected considering we have 2 cylinders but only replaced one with solar. Thanks to a power hungry guest we only generated about $107 credit for the last quarter but if he goes mid march as promised I expect us to have nearly 300 in the kitty towards the winter bill which should go close to covering it. Solar is awesome 

[mjt57]

It's a pity Hydrogen is so volatile and difficult to store in usable quantities.

Why is it difficult to store? It's a gas. It can be stored compressed in cylinders.

As for being volatile, it's the same as any flammable gas that you may have on your property, such as LPG, natural gas, acetyline, but to name 3...

Anyway, as for the argument regarding cost recovery, we didn't even consider it. We're looking at long term when the PV will help offset our energy bills as we head into retirement. That dough could've been spent on a new bike, a holiday, furniture or anything else that depreciates in value as soon as it's purchased.

So, whether it takes 2 or 10 years to pay itself off, we don't care. The system is in, it's working, our bills are already cut by one third and that's taking in our central A/C at the front of the house and the inverter A/C at the back (extension).

As for looking at an inverter microwave oven, I'm not sure if there are any savings there. We went from an old clunker of an LG to a Panasonic inverter recently and I can't tell from the power usage if there is any difference. Remember, if you're running the MW flat out to heat something up it still uses as much power as an equivalent non-inverter MW.

What does spike significantly is the toaster and the kettle. Can they be "inverterised"???

[Aussie Keith]

Appliances that really consume power is the dishwasher and electric oven. Air conditioners not as much as you might think. Electric kettles as well and microwaves also but they are only used for a minute or so at a time.

[Phil №❶]

Regarding the properties of hydrogen gas. Normally, usable quantities of gas are stored as a liquefied product. This is basically unachievable in a domestic circumstance and certainly not allowed by the local authorities. the danger of container failure with or without an ignition source is just too high. To keep hydrogen as a gas, means using a low pressure storage vessel, eliminating any oxygen in that vessel, otherwise an explosion will certainly result. Having said that, Hydrogen is lighter than air and would essentially dissipate into the atmosphere unlike LPG which is heavier and hangs around on the floor to burn or asphyxiate you.

Hydrogen is extremely volatile, more so than other gasses. The flame front of Hydrogen is measured at 4 metres / second compared to other gasses at 0.5 metres / second. This is due to the rapid combination of Hydrogen & available Oxygen. The stoichiometric ratio provides an explosive mix.

It would be great to liberate Hydrogen during the day & recombine it safely, using a fuel cell at night.

[beerman]

Most places with good sunlight would benefit from a 3.0kw system even with low FIT, especially if they can change their usage patterns (eg programmable dishwasher and washing machine so that they kick off from about 10am to make the most of the free energy)

[Surferdude]

Regarding the properties of hydrogen gas. Normally, usable quantities of gas are stored as a liquefied product. This is basically unachievable in a domestic circumstance and certainly not allowed by the local authorities. the danger of container failure with or without an ignition source is just too high. To keep hydrogen as a gas, means using a low pressure storage vessel, eliminating any oxygen in that vessel, otherwise an explosion will certainly result. Having said that, Hydrogen is lighter than air and would essentially dissipate into the atmosphere unlike LPG which is heavier and hangs around on the floor to burn or asphyxiate you.

Hydrogen is extremely volatile, more so than other gasses. The flame front of Hydrogen is measured at 4 metres / second compared to other gasses at .5 metres / second. This is due to the rapid combination of Hydrogen & available Oxygen. The  stoichiometric ration provides an explosive mix.

It would be great to liberate Hydrogen during the day & recombine it safely, using a fuel cell at night.

Hindenburg disaster - Wikipedia, the free encyclopedia