Solar for my home

[manchu]

I thought I'd get the content ball rolling with some silly questions and brainstorming for a future solar setup at my current home.  

Our house is  in North Warrandyte,  VIC.  We've been there a few years and plan on staying there long term while raising our 3 boys (2,4,7yo).   4br, 2 story, double brick.     Heating by: wood fire,  gas ducted,  split system.      Cooling by:  1 split system and 1 window AC.    Gas Hot water

18 months ago I had a local installer out to inspect and quote a 5-6kW system.     The cheap option was $10K  (winaico panels ) and the expensive $12K (LG Panels), both using Enphase micro inverters.   I knew this guy would be a bit more expensive than the cheap ads you see around,  but I wasn't expecting over double so I lost interest.     Those quotes showed  a payback of ~9yrs,  which I suspect is optimistic.       

Some general question to start with:

 - how to get an honest assessment of how well solar will work for us,  considering factors like the available sun and our actual energy usage.       (I don't want the solar to only be beneficial  IF we change our hot water to elec or stop using the wood burners).    

 - Should I get batteries now?       

 - Panels and other hardware...how cheap is too cheap.    What are the good and bad brands at the lower end of the market.

 - Are all cheap installers to be avoided?      (The guy who quoted me mentioned they come and go so long term warranty is a big concern.   I certainly agree with the notion of not buying junk or using dodgy trades,  but I'm skeptical of advice coming from someone with a vested interest in me opting for premium).   

 

thanks in advance for any tips. 

 

 

[koputai]

The first questions should be:

1.  How big, what shape, and which direction is your roof?

2. Is there any shading between 9am and 3pm?

 

An aerial photo from Google Maps or Google Earth would be a great start.

I'm sure there'll be tons of argument threads here soon in regard to string vs micro-inverter setups, but if your roof is like mine (north facing, no shading), the simplicity of a string system is great.

What is your average kWh usage per day? When are your main loads on, air con, any resistive heating like underfloor, swimming pool or spa?

Is your meter time-of-use or single rate? Some providers will require you to change to a time-of-use meter when you install solar.

Commercially available battery systems don't pay themselves off yet. You're best to get the best feed-in tarriff you can, and move all your loads to the cheapest available time, which may well not be when your solar is producing power.

 

Cheers,

Jason.

 

 

[manchu]

cheers Jason.  
 

house is on the east side of a fairly steep hill   Roof pitched and quite large (15x8m Approx). Biggest side faces East and is  unshaded from 9 to 3, (not at all in summer and maybe only a little worse in winter.)

15 kwh /day Average usage through the year.   Main load is air on only   Rest is just usual household appliances   

time of use I think   🤔 

 

that’s what I figured about batteries now   

 

 

 

[Marc]

On 7/13/2020 at 6:00 PM, koputai said:

Commercially available battery systems don't pay themselves off yet. You're best to get the best feed-in tarriff you can, and move all your loads to the cheapest available time, which may well not be when your solar is producing power.

Totally agree with this. I desperately want batteries is our highest power consumption is between 6PM-9:30PM, and we have obviously have zero solar output at that time of day. As @koputai says though, despite my constant price checking I can't yet find a cost effective battery solution. I'm told next-gen of batteries will be coming out towards the end of 2020 (that advice was pre-COVID though), and that there will be more grants and cheaper pricing (VIC). We shall see.

In regard to getting your solar - I spoke to as many friends as I could, got info from forums (SN), and ended up getting 5 quotes in total. By the time I'd had those quotes and speaking with each of them on site, I had a much better understanding of it all and the different opinions each company had on the best solution. Then you just go with your gut I guess.

[manchu]

Thanks for the input Marc.  
 

I’ll be getting another quote soon from this guy.  http://www.yarrasolar.com.au. We’ve got kids at the same kinder/school and  we recently realised he’s my cousins best mate since the 70’s so I hope to get a fair price.  
 

I’m also quite tempted to go down a DIY route if its feasible.  We occasionally do solar for remote mining/oil & gas projects at my work so have good access to a lot of the materials.  (I could probably wire the lot up in ‘free’ steel wire armoured cable if I wanted )

i bought And installed a small solar panel and Victron  charge controller  for my caravan battery  earlier in the year so have got my head around it a little.   House is obviously different and needs professionals involved in some way 

[koputai]

A rough estimate of your solar yield based on your location and roof layout, with a 5kW system on your East facing roof, you would average around 16kWh per day over the year.

As long as you get a decent feed-in tarriff, it would be worth doing.

 

Cheers,

Jason.

 

[manchu]

Good.  Cheer
 

another consideration in all this is the fairly unreliable power in my area .   We have at least one short outage a month on average.    

Wondering about a small battery setup to handle just 10min or so backup power.  ?!
 

 

[gibbo9000]

This calculator may help you get a handle on what you could generate.  https://solcast.com/rooftop-solar/free-pv-system-performance-estimation-tool/  Quite a useful site overall.  One of the ones a few people use to get solar forecasts for the next day to help manage batteries.

57 minutes ago, manchu said:

Wondering about a small battery setup to handle just 10min or so backup power

The thing to be careful of here is the maximum charge / discharge rate of the battery.  The smaller batteries (1 - 2 kWH) are good for time shifting during the day (lots of small periods of storing / discharging) but not great for backup as their discharge rates are limited to max 1 - 2 amps, not enough to power a house.  There can also be a fair bit of rewiring of switchboard to separate out the backed up circuits.

[manchu]

11 hours ago, gibbo9000 said:

The thing to be careful of here is the maximum charge / discharge rate of the battery. 

 . . . . not enough to power a house.  There can also be a fair bit of rewiring of switchboard to separate out the backed up circuits.

cheers. I thought that might be the case.  

[Marc]

On 7/16/2020 at 11:27 AM, manchu said:

I’m also quite tempted to go down a DIY route if its feasible.  We occasionally do solar for remote mining/oil & gas projects at my work so have good access to a lot of the materials.  (I could probably wire the lot up in ‘free’ steel wire armoured cable if I wanted )

I don't know for sure but I think this might be practically impossible. The industry has become so regulated now, and even though some of the installers out there might be better suited to washing windows, I think the red tape and inspections process would see no solar company allowing you to supply or install any part of the system that ultimately they get signed off to their name.

The inspections process (in VIC) has apparently caused many installers to leave the industry. Whether it was because their work was not up to standard in the first place, or whether the inspectors are being over the top, depends on who you speak to. Either way, there's nothing wrong with being too thorough when it comes to PV and safety I think. My inspector seemed to know his stuff and seemed a reasonable bloke.

[manchu]

On 7/18/2020 at 9:08 AM, Marc said:

I think the red tape and inspections process would see no solar company allowing you to supply or install any part of the system that ultimately they get signed off to their name.

Not surprising I guess.       

[manchu]

I'm really tempted by a 'too good to pass up' deal I saw yesterday.    It's a young company (~2yrs),  but feeback I've found has been positive so I think I'll take a punt.

The package includes: 

 - Seraphim 330W panels  (25yr performance and   15yr product warranty)

 - 5kW Growatt Inverter  (10yr warranty)

Other products are available for extra cost so I'm after opinions on whether it's worth chipping  in more (say ~ $1000) to improve  the system ??   (eg.  increase size,  different  panels, inverter or otherwise)      Thoughts?  

 

Edited July 24, 2020 by manchu

[Marc]

I don't know anything about those panels so can't say really. The advice I was given was to definitely spend more on the panel and inverter quality. The other advice was to get the biggest system you can afford now, as it costs more to add on later.

Hopefully one of those more experienced with the brands on the market can chime in before you commit. 

[koputai]

I’m never a person to go with the ‘budget’ option as it’s usually just ‘cheap’ and leads to disappointment.

 

For perspective, I went with a Fronius inverter and QCells panels, $10,500 for 8.58kW. I expect payback to take less than four years.

 

That said, my brother in law went with a Fronius inverter and cheaper panels. He paid a lot less than I did, and got 11kW. His payback will be even shorter.

 

Going with cheaper will likely pay for itself in a reasonable time frame, but you’ll probably be pulling them off the roof in ten years to replace them.

 

Cheers,

 Jason.

 

[manchu]

thanks for the input guys.  

I've asked installer for their recommendations where to spend extra money.    Fronius inverter and Jinko panels seems like a common combination they do for better systems.    

[manchu]

I received my quote yesterday then tweaked it a little to change layout,  inverter and  panels .    Their proposed layout was 10 panels east side + 10 west side,  but due to the west side being much more shaded than the east I thought it was best to keep them all on that side.   

 

Panels were changed to higher output (18 x Jinko 370w panels) to allow all to fit on the large south east area of the roof.       Inverter changed on installer recommendation (Sungrow SG5K-D inverter 5kW) .   

  

 

Total system =  $8082 

86 STCs = -$3182

VIC PV rebate = -$1850

VOC PV Loan = -$1850

Total up front = $1200.   

 

 

 

 

 

 

[koputai]

Wow, you guys down there in VIC get these systems cheap!

 

A quick run of the numbers, that system should average about 20kWh per day over the year, from around 32kWh/day in Dec/Jan, to 8kWh/day in June.

 

Cheers,

Jason.

 

[manchu]

I'm now wondering if I should increase the system size and go back to a split design.   eg.    8kW  with  16x330w panels on  east side and 8 x 330w  on west side

If I'm being realistic I don't think we'll be very good and changing our usage to suit mostly morning energy production,  so some on the west side would be good.       It might mean I need to trim a few tall trees nearby to reduce the shading,  but that's OK.   

 

 

 

 

[Marc]

2 x Fronius inverter and 37 x Jinko panels are what I use in my system (11.65 kW) It's not Greenlink Solar by any chance is it?

This is our layout with the bulk of the panels N facing.

My advice is get the most panels you can fit/afford - it costs a LOT to add more later. I covered most useable area up front based on this advice, the only condition was that no panels could be seen from the two road frontages we have. It worked out perfect.

[manchu]

19 minutes ago, Marc said:

2 x Fronius inverter and 37 x Jinko panels are what I use in my system (11.65 kW) It's not Greenlink Solar by any chance is it?

 . . .

My advice is get the most panels you can fit/afford - it costs a LOT to add more later. 

 Company is Pristine Solar (came across the deal on ozbargain).   

yeah,  most panels I can afford now is my new thinking.   We have the $$ available so it's better to invest in saving money than just offsetting the mortgage.    

I guess I could afford and have room for more than 8kW of panels,  but I think returns would be somewhat diminishing as I'd start encroaching on areas that get partially shaded.   

Fronius adds another ~$1K on the Sungrow.    I did a bit of reasearch into the sungrow and it seems to be one of the better cheap inverters and reasonably well regarded so I think I'll stick with it.

another change I was thinking is for Winaico panels.  Partly because the better warranty, performance, but also  because they offer a 2yr 'insurance'.    We had 2 cars written off due to hail storm in Jan so I'm worried how panels will hold up.        

 

 

Edited July 29, 2020 by manchu

[manchu]

Received the quote for the bigger system, consisting of  28 × 370W Panels  ( LONGi  or JINKO )   +   Sungrow 8kW inverter

• Subtotal $12,175
• 135 STCs 7 × $37.00 −$4,995
• Victorian SolarPV Rebate −$1,850
• Victorian SolarPV Loan  −$1,850 
• Total inc. gst =   $3,480 up front (post rebate and loan)    => total out of pocket = $5330)

So,  that's a $2280 extra over the 5kW system  using the same components.      I reckon I'll go for it.   

 

 

 

 

[Full Range]

In not sure about other states 

But here in QLD we are export limited to 5 Kw inverter 

I elected for a 6.6kw PV system with a 5 Kw sungrow inverter capacity 

My plan is to add battery storage when it becomes feasible 

[Marc]

21 hours ago, manchu said:

Received the quote for the bigger system, consisting of  28 × 370W Panels  ( LONGi  or JINKO )   +   Sungrow 8kW inverter

• Subtotal $12,175
• 135 STCs 7 × $37.00 −$4,995
• Victorian SolarPV Rebate −$1,850
• Victorian SolarPV Loan  −$1,850 
• Total inc. gst =   $3,480 up front (post rebate and loan)    => total out of pocket = $5330)

So,  that's a $2280 extra over the 5kW system  using the same components.      I reckon I'll go for it.   

For comparison sake, that's about $3K+ more out of pocket than my system (only in January this year), and at least 2kw less capability than my system (two x Fronius Primo 5kw Inverters, 4 x total strings). Would you like my installers details for a quote (also in Melbourne)?

[manchu]

12 hours ago, Marc said:

Would you like my installers details for a quote (also in Melbourne)?

Sure.  Shoot me a pm please.  
 

[manchu]

Updating this thread as my system went in yesterday.    A whole bunch of the Jinko 370W panels some optimisers for one section and an 8kW Fronius inverter.   

I didn't end up contacting your installer @Marc as I'd pretty much decided to go through my cousins mate/local installer if I got a good vibe and a price reasonably close to 'cheap' upstart mob,  which I did.        He squeezed my install in very soon after VIC lockdown eased (others I know who ordered elsewhere before me are still being told a few weeks),  and did a great job from what I can tell.  

I'm limited to 5kW export due to single phase so there's a bit of lost capacity,  but probably not too much on average.     

Now  I just need to decide on energy retailer.    I'm currently with origin so checked with them.    Origin   'Solar boost' plan is as follows.  Seems about as good as I'll get for FIT in VIC

 

FIT 15c, no cap, 12month
supply rate 30.72 c/kWh (0% disc)
supply charge 114c/d