# Forum Home Renovation Solar Electrical Systems  new round of phone calls wanting to sell solar panels

## pjt

Hi all,
Seems that the upcoming review of the solar rebate is bringing out the solar panel sellers, one door to door and phone calls, I have in the past said no, me being a tight ass and not wanting to spend the money :Wink 1:   however, had a face to face chat with a young guy today and I'm a little more tempted, basically his pitch is whatever you spend on your power bill is what you spend on the solar system if I understand his sell correctly, also with Li Ion batteries for storing the excess above daily household use for then using at night time, he did say that batteries are too expensive at the moment tho but expects them to come down, with two of us home most of the time the better option is to use the generated power rather than sell it back. 
Last bill daily usage was about 14kWh, this can still be trimmed with turning things off etc.
 Panels on offer are German made MUNSTERLAND 1.5kw and Solax hybrid inverter 3kw .
Has there been much talk on these brands or any other relevant thoughts on these battery hybrid systems? 
Cheers,
Pete.

----------


## METRIX

What are the rebates, typical backwards 1st world Australia, introduced the Solar rebate system a few years ago, and was giving something like 60c per kw feed in tariff, this has now dropped to 6c, they allocated a certain amount of money for new systems thinking it would last for many years worth of rebates but the money ran out very quick as the uptake was more then they expected, (typical gov't no idea overpaid boffins that have no idea of what we want). 
Reading up on it recently. it's basically not worth getting a stand alone system as all the power which is being generated during the day is not to your advantage, unless your running a business from home, and are drawing decent power all day, otherwise it's only driving your fridge, and standby devices. 
Otherwise it's all going back to the grid (which is a good thing) but you get basically nothing for the thousands you need to outlay, this is where systems like TESLA come in, you generate power, ans store it locally, then when you come home and turn everything on the power is drawn from the batteries, this is going back to the "old" way of doing it, but just in a new modern smaller package. 
I noticed now AGL is offering 7.2kw battery systems, but still around 10K. AGL Energy Offers 7.2kWh Battery Storage For Less Than $10,000

----------


## joynz

Hi pjt 
I have had a 1.5kw system since around 2010.  With a 60 cent feed in tariff and using about 3 kw a day  in summer and 9kw a day this (cold) winter, I have no summer electricity bills but do get bills over winter. 
I'm not sure what your rep means by saying 'whatever you spend on your power bill is what you spend on the solar system'?  Solar has worked out really well for me but I'm not sure I'd bother if I was making the decision now - apart from the sustainability aspect and you can be part of this just by purchasing green power for a few cents more per kw. 
I'd be very wary about any claims about your bill being reduced - unless you are usually at home during the day.  Watch out for higher service charges too - my service charges went up a lot when I went to the solar feed in tariff.

----------


## UseByDate

I am still not convinced of the economics of a 7.2 kWh battery at $10,000.
 I pay 30c per kWh for electrical energy and a FIT of about 5c per kWh. If I had a solar set up I would be able to store  7.2 x (30-5) cents of energy (for free use at night) a day. Ie  $1.80 per day or $657 per year.
 This assumes that the solar system is large enough and the weather is sunny enough to fully charge the battery in a day. That one uses all the stored energy at night. That the battery can be 100% discharged.(some batteries can/should only be discharged 80%.). The batteries capacity does not diminish over time. One uses the battery every day eg no holidays. If all of these conditions are not met then the savings will be significantly less than $657 per year.
 If we are generous and assume a saving of $500 per year the payback time is 20 years.

----------


## Bloss

The QLD review will not come out with a worse price for energy exported to the grid (currently around 5c-7c kWh - sometimes less sometimes more) and might come out better (unlikely to be more than 8-10c kWh). Self - consumption mostly saves the offset retail price so that is real saving. The cost of PV is a capital cost and the offset savings will go on regardless of what electricity prices do - even if they don't go up (hands up who thinks they won't?) your savings stay for the system lifetime of 20+ years. 
If you have an electric HWS then you should be directing PV power to that during the day (either are switches and sensors to do this cheaply) as for most households hot water is around 30% of energy costs. When you buy a PV system you are effectively buying future energy at fixed and known cost. Once the system is paid off the 'fuel' is free so the longer it runs the cheaper the overall average cost will be. Energy from the network (grid) will increase by inflation at least and probably more - regardless of what the generation source is - around 50% of that cost is the network costs (poles, wires, transformers & substations) and a line loss on average in Australia of around 8%, but in some states (such as parts of the Ergon Qld network these can be as high as 25%!) PV used at your house has no line loss. 
Battery storage is not yet there as a cost per kWh for most urban residential, but the prices are coming down quickly - Tesla is the Apple model and their will be a range of storage options just as good and cheaper including some made here. The price structures right now do not encourage take-up of PV or storage and networks are fighting to get revised prices in place to continue those barriers - but there is considerable consumer and political resistance to that. 
A PV system is a long life long term revenue earning asset  - so an investment matching your house investment. Those lucky enough to have been given a 44c FiT won the lottery, but even those buying now it is a good deal and better than most things you spend money on that cost money and will never earn it- e.g.: cars depreciate, house depreciate, boats depreciate and so on. 
The key right now is to try to match the system size to your day time use - but heat HW with it too. Late afternoon A/C use can also offset by PV - and think about the best orientation. Average annual production is best when facing a due North or a little East or West of that and at roughly the same angle as the latitude of the location, but given there will be time of use pricing sooner than later and peaks are mostly in late afternoon a West facing system has benefits (as there will be higher charges when there is most demand on the network) - or a mixed orientation with mostly West some North and some East. The time value of energy is not captured in current pricing systems - but will be very soon. 
Also useful to look at oversizing the panels capacity to the inverter size - the reverse of what many will try to sell you. The reason is that the inverter has maximum output (94-97% of rated capacity), but is often running well below that during any day. If you add panels (say 25-30% more than rated capacity usually just one, two or three panels extra)  then the period that it will sit at its maximum output will be longer (the output curve will rise faster and be flatter). That is extra energy at marginal extra cost. This does not damage the inverter or panels.

----------


## JB1

> If we are generous and assume a saving of $500 per year the payback time is 20 years.

  Or you could stick $10k into your mortgage and get a return of $500 tax free every year  :Smilie:  
I did my sums and found solar not worth it yet (7 Cent feed in tariff).  
In a few years I will look at it again... higher efficiency panels, lower prices, battery storage are a given over time.

----------


## Bloss

> Or you could stick $10k into your mortgage and get a return of $500 tax free every year  
> I did my sums and found solar not worth it yet (7 Cent feed in tariff).  
> In a few years I will look at it again... higher efficiency panels, lower prices, battery storage are a given over time.

  If you are exporting all or most of your power then a 7c/kWh price is too low, but you need to account for offsetting your own use and that will be at the rate you are charged for the energy - usually >14c and sometime much higher. PV works at any price above 12c/kWh . . . Even if the fixed charge increase the energy charges have generally not gone down and that is what PV is reducing. And increasing energy use during daylight hours (e.g.: for A/C, washing machines dishwasher and hot water systems) will add to the savings through PV being used as self-consumption behind the meter. 
Remember -  The cost of the PV energy is fixed and known and does not increase over time (in fact reduces due to inflation unlike every other energy charge).

----------


## Marc

> I am still not convinced of the economics of a 7.2 kWh battery at $10,000.
>  I pay 30c per kWh for electrical energy and a FIT of about 5c per kWh. If I had a solar set up I would be able to store  7.2 x (30-5) cents of energy (for “free” use at night) a day. Ie  $1.80 per day or $657 per year.
>  This assumes that the solar system is large enough and the weather is sunny enough to fully charge the battery in a day. That one uses all the stored energy at night. That the battery can be 100% discharged.(some batteries can/should only be discharged 80%.). The batteries capacity does not diminish over time. One uses the battery every day eg no holidays. If all of these conditions are not met then the savings will be significantly less than $657 per year.
>  If we are generous and assume a saving of $500 per year the “payback” time is 20 years.

  Why not get yourself a bank of batteries, hook them up on off peak power and charge them at night and use them the rest of the day?

----------


## phild01

> Why not get yourself a bank of batteries, hook them up on off peak power and charge them at night and use them the rest of the day?

   Good thinking, so when batteries are feasible we can expect the removal of cheap off-peak then.

----------


## UseByDate

> Why not get yourself a bank of batteries, hook them up on off peak power and charge them at night and use them the rest of the day?

  Good idea but;
"Off peak electricity" as defined in South Australia ie "controlled load tariff" may only be used for approved applications and charging electrical batteries is not one of them.

----------


## Marc

Considering the abuse, bulling, extortion and over regulation the consumer of electricity is subject to, I wouldn't feel bad at all to have a stack of batteries under the house hooked up to the hot water ... Not even in SA

----------


## UseByDate

> Or you could stick $10k into your mortgage and get a return of $500 tax free every year  
> I did my sums and found solar not worth it yet (7 Cent feed in tariff).  
> In a few years I will look at it again... higher efficiency panels, lower prices, battery storage are a given over time.

  Option 1.
 Buy battery. After 20 years one would have just paid off the battery with energy savings. Ie no net gain. The battery is only guaranteed for 5000 charge cycles ie 13 years so its capital value would be zero and one would also have to pay disposal costs. 
 Option 2.
 Invest for interest. After 20 years of interest payments one still has the capital (or a reduced mortgage of 10K ) ie a gain of $10,000. 
 Minimum FIT for Victoria is now 6.2c per kWh.

----------


## joynz

Actually you'd have an even greater benefit than $10,000 off your mortgage, once you take the effect of compound interest into account, over a couple,of decades!

----------


## pjt

Thanks everyone for the replies, much to digest, to add some points.....we are both home most every day so can use what is generated, for the house in summer that will be a small window AC, it uses about 1.3kw, this is the single biggest power consumer in the house during summer it goes very close to 24/7  :Frown: plus various ceiling fans and lights, fridge, washing machine, tv, then there's my woodworking machinery, could be as much as 6kw, (one machine plus dust extraction) plus lights and a power tool or two,  total use per day tho is low so doesn't represent a high portion to the total useage, and being 3ph would probably be just as easy to buy from the grid, not sure on this tho. 
House is paid for so no mortgage :Smilie:  
We have solar hw with low tarrif backup which last quarter cost about 24% of the total, this should reduce for the summer and two less people in the house who both like long showers. 
Current general tarrif is 24.4c/kwhr, it came down from 27.9 part way thru the quarter, the current FIT is 6.34c/kwhr 
House ridgeline is close to due north so easiest mounting for the panels would be east/west combo, this had me thinking about orientation, as I understand it panels work best if their orientation is facing the sun and at the correct angle of tilt, I don't think I've ever seen any house panels where much attention is paid to this, they seem to be just placed where they can get them, Is this just the way it is? or Does it add too much cost to start considering tilt and orientation and What about tracking?    
Pete

----------


## Marc

Window A/C ? Get a new split and save half the cost of running it.  
As far as all matters solar, this website has a lot of sensible answers, from new install to upgrades. It is so obvious that the government should stay out of ... well almost everything. Whatever they touch turns to mud. Sort of, the reverse Midas touch. https://www.solarquotes.com.au/

----------


## notvery

PJT
your in rocki so... https://www.ergon.com.au/retail/residential/homesmart 
i am aware of the technology behind it. not commercially involved but it is awesome... i have been behind the scenes as it were...HabiDapt 
works real well with making your solar system / pool / aircon etc much more efficient.

----------


## METRIX

> Window A/C ? Get a new split and save half the cost of running it.

  Exactly what I was going to say, if your spending money on getting Solar, definitely spend some more and get a decent Split, make the place more livable, and next to nothing to run through the day.

----------


## BRADFORD

This might be of some help, actual performance figures from my solar system.
Since I'm in a fairly remote area I have to read my own meter, so some years ago I set up a spread sheet to monitor our use  and to ensure our bill was actually correct.
When we installed solar I expanded the spreadsheet to give me much more info then the inverter does.
System size 5kw, cost $9260.00 including supply authority charges (this would be much cheaper in the city).
Average daily consumption total 13 units consisting of 5 units imported at 25.7 cents per unit inc GST and 8 units supplied direct from solar.
Average daily export 19 units at 7.13 cents per unit.
Yearly figures are Import cost     $470.00
                          Supply charge                       $154.00 
Export credit                         $494.00
Annual electricity cost            $130.00
Normally this would have cost $1373.00, so my solar system saves me $1243.00 per year, and that represents 13.4% return on my investment, try and get that anywhere else these days.
Our panels are north facing and angled at 25 deg. with no shading whatsoever, also we live in a low rainfall area so we don't have many rainy or cloudy days.
The same system an another area may not perform as well, however even if you dropped the above performance by 20% it is still pretty good.

----------


## pjt

All good info....cheers. 
I dropped into one of the local solar shops and made a time for a chat at home, it was interesting to see the different approach, more technical explanation regarding how the solar system will work given my east/west roof orientation and other useful info,  not so much of the hurry to sign me up approach, he wants a few days of meter reads to get a better feel for our useage before he makes a decision on a system.    
Pete

----------


## Bloss

A others have said you'd get a faster and better return on your money at least ion the short term by getting a high efficiency A/C to replace the old one you have.

----------

