Home Solar ROI

[D4D]

Yes I have searched and couldn't find another thread on this.

Like everybody else I have some home time on my hands at the moment so I have been revisiting solar.

Got a couple of quotes, they range from the cowboy 'you'll save 1 billion dollars with solar' to the detailed engineering style dudes, which is prefer.

We use power in the morning and evening, no pool or refrig aircon, only a couple of fridges on during the day, latest bill daily average is 18KW.
Our house faces north but the panels need to be on the west roof line due to wife acceptance factor.
West roof line is on the high side of the street with no shade at all to the west or north during the day.
Current electricity distributor has a 5KW max infeed limit.

The quote I am favouring is - 19 Jinko panels 6.2KW total, Fronius Primo 5KW Inverter, with an estimated 20KW per day output, $10K before rebates, with the federal rebate that makes it $7K.

Current infeed rate of 15 cents = $1100 in credit per year best case = 7 year ROI.

To me 7 year ROI is still a long time, what am I missing?

[Bird]

There have been a few threads on this.

Someone on here was involved with Solar from memory... They were saying if your not home during the day when the most power is available - wasnt worth it - unless you have batteries.. they charge up during day, you use morning/night from batteries

[D4D]

Someone on here was involved with Solar from memory... They were saying if your not home during the day when the most power is available - wasnt worth it - unless you have batteries.. they charge up during day, you use morning/night from batteries

Yeah I have come to that conclusion also. Batteries add another huge cost that pushes the ROI way out. You'd get a better return putting the cash in a 10 year bond.

[plusnq]

Agree with Bird. I work from home, we have 6.5KW with a pool, aircon and several fridges. Our inverter failed and our bill for summer went from $800 to $2999.We save about $500 per month usually with the solar so the ROI was about 3 years when installed seven years ago. Once we can get a new inverter we are adding in batteries and more panels. Unfortunately we haven't been able to get a suitably sized inverter since mid February.

[db]

7 year payback is equivalent to just over 14% interest P/A. Yes that ignores compounding, but that is still a healthy ROI. I'd challenge you to find an alternative that returns as well.

[chester ver2.0]

There have been a few threads on this.

Someone on here was involved with Solar from memory... They were saying if your not home during the day when the most power is available - wasnt worth it - unless you have batteries.. they charge up during day, you use morning/night from batteries

That was the same conclusion and info i got when i was quoted last year and also had an engineering friend look it over. As it is only the 2 of us and both of us are out during the day most days of the week it was not worth it unless batteries were included to store the power during the day and we would use it at night and be almost off grid

[Beachman]

We got Solar installed last year and I got 2 quotes then compared this with 2 quotes a neighbour also got. So all 4 companies were recommendations from friends and using smaller companies offering quality products.  None of the big companies advertising on TV.

So for the run of the mill set up (6.2KW total, 5KW Inverter) 3 or the 4 were priced within $50 at around $5 394. The 4th company was Origin who were by far the most expensive by around $1 000, but their sales pitch is to pay the bill off over 3 years with your power bill.

A mate who is an electrical engineer recommended I ask what a bigger system would cost (Only because in summer this would cover the running cost of our ducted A/C during summer during daylight hours)

So I also got a quote for a 8.19KW with a 7.5KW  Inverter which came in at $222 more expensive than the above system. But I have to say all power companies cap at 5KW what you can send back to the grid, so my theory is by the time we take account the pool pump and maybe a dishwasher/washing machine or TV going, I’m still sending power back to the grid. 

Our power bill was always around $500-$600 per quarter (We have gas hot water and cooktop) Since Solar our first full quarter bill was $148 in credit (But we were away for 3 weeks in summer which helped) and our second bill was $131 debit, (But this was in the middle of summer of the A/C copped a flogging) so Zero seeing I kept the above credit on my account.

We have 26 panels in total, 16 of these are facing North as that’s all that would fit and then had the option to put the other 10 East or West. Seeing my Wife does the housework in the morning dishwasher/washing machine/vacuuming in the morning, we put the 10 facing East for the morning sun.

In December on a clear day they were producing a total of 50.2kWh with the worst for an overcast day down to 24.73kWh according to the app on my phone.

Come April on a clear day they were producing a total of 43.25kWh with the worst on an overcast day down to 18.26kWh according to the app on my phone.

These amounts will reduce as the days get shorter, but I have to say that while Origin was the most expensive, his forecasts on that the systems would produce were the most accurate. 

For us to major benefit of Solar is in Summer when the family says it hot and askes about A/C. Instead of saying let’s hold off a little longer it’s a straight turn it on.

[Fizzie]

From discussions on Whirlpool, home batteries just aren't worth it "yet" - 10 year ROI for something with a 10 year warranty There are supposed to be changes "coming" that will make it worthwhile but they're still a coupe of years away

We put solar in (against objections from Mrs ) early so we got big FiT rebates, so our was paid off <3 years , but as DB said, 7 years is nothing to be sneezed at

[GeoffA]

......But I have to say all power companies cap at 5KW what you can send back to the grid......

....unless you have 3 phase, then it's 30kW (for us, some are 15kW max) and away we go....

Who needs batteries??...

 

[MB TD42]

Some may not realise the kind of pressure unused solar poses on the grid as well...exess power flows into the grid and surplus creates a need to shut down power trains that are connected to that particular grid...takes 30mins to an hour to restart the powerplant/generator so you can imagine the result of a couple of patches of clouds on a hot day...

Battery tech needs to be advanced to counter the rolling blackouts.

Bit like how a power supply protector works for your home or business.

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[WilSurf]

....unless you have 3 phase, then it's 30kW (for us, some are 15kW max) and away we go....

Who needs batteries??...

 

We have 3 phase, but still capped to 5kW as we are not as business.

[GeoffA]

We have 3 phase, but still capped to 5kW as we are not as business.

Bummer....

[GBC]

Have you done your ROI calcs right? Did you allow for the continuing (and probably increasing) power bills as well?
We did a deal that we continued paying the same as what we would pay on a usual bill. Paid itself of in just under 5 years - about 5 years ago. It is a no brainer. We could only fit 3.5 kw on the roof (solar HWS in the road), but we bought the best gear knowing it is a long term bet.

[Bird]

it was froM Brian .

http://www.myswag.org/index.php?topic=55591.msg970050#msg970050

[KeithB]

We put a large system in about 18 months ago and have not had an electricity bill since. We have a pool and are all electric except for the cooktop. We also connected the off peak water heater to the solar to come on mid afternoon. Our panels face almost due west.
We have 10KW of LG solar panels on the roof, each with its own mini inverter, and a 14KWH Tesla battery. The whole thing came to about $29K. As I write this we have 6.6KW coming off the roof with almost all of it going back into the grid because the battery is full.

I did a discounted rate of return spreadsheet based on the following assumptions.
1. We would generate all of our own power for the 25 year life of the panels.
2. The battery would hold out for that period. I reckoned that a replacement battery in 10 or 15 years time would be much cheaper than now.
3. That power would escalate in cost by 2% a year from here on.

This gave an equivalent rate of return of just over 11 per cent per annum. That's better that we can get in super.  Incidentally, the ten year government bond rate is currently just 0.83 per cent per annum.

Keith

[BC66]

Hi all
I worked for a solar component wholesale business a while back.
A few things to consider when buying is what components are used as there is a big difference, remember you get what you pay for.
Ask for data sheets on panels, you may not understand what’s written but compare everything.
Panels do degrade, have cyclone ratings etc.
They are forever evolving and getting better. Buy what you need now and don’t plan for the future because as panels age they may not be compatible with newer panels and you could have to replace all of them if you plan to upgrade later.
Read the warranty carefully on batteries, especially the LG and Tesla.
A 10 year warranty is not that straight forward. It’s based on data collected within the battery and depends on depth of discharge and cycles.
These batteries are very clever.
Same goes with inverters. Buy quality, look up reviews, compare.
You may notice the ads on tv for cheap systems, but have you noticed the name of the supplier is always changing?  It’s often the same company, buys cheap products , goes broke and restarts up again under a new name
Any way that’s my tips and 2 cents worth.


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[D4D]

Thanks for all your thoughts, I'm still on the fence...

[GeoffA]

Jamie,

I don't see an allowance for a reduction in your power bills in your ROI calcs. Seems to be based purely on FIT. Have you included it?

A big consideration for us installing solar was that we can pay for it while we are still working, and we'll have reduced bills when retirement hits in a few years.
Our installation fully covers both electricity and gas bills, but that's not available to everyone.

 

[xcvator]

We got ours under the Vic. subsidy scheme, paid about $3000 and have saved about $700-00 off of our power bill in just over 11 months , pretty happy with that 

[Mace]

I don't see an allowance for a reduction in your power bills in your ROI calcs. Seems to be based purely on FIT. Have you included it?

Even down here in Tassie, an average of 37% of our produced energy  goes to powering our home instead of  FIT.  We have had our system since November, and the 2000 approx kw we have used directly since then  has reduced our bills by $360 in total.

Our $500 per quarter (summer bills) have reduced to less than $100.

Its been a no brainer for us, and we are not home all day.

 

[Fizzie]

Also have a look at PV Output https://pvoutput.org/ladder.jsp?c=1&r=Victoria & see of you can find a system close to you to give you real information on performance in that area.

[Bird]

Wazbot on here got onto the solar gig when it FIRST came out and the sell back to grid prices were huge...
His gas and electric have been free ever since as he gets a chq back for the feed back amount which covers gas...

The issue he has is if something fails, or he wants to upgrade, then he loses that original feedback $ amount and goes onto the latest $ amount

but the feedback $$ amount now is a pittance.

Dirty prick

[GeoffA]

Wazbot on here got onto the solar gig when it FIRST came out and the sell back to grid prices were huge...

I don't think that's forever, though.....

.....but the feedback $$ amount now is a pittance.

For us, the FIT ends up being about half the buy price, after pay on time discounts.

 

[Fizzie]

Wazbot on here got onto the solar gig when it FIRST came out and the sell back to grid prices were huge...
His gas and electric have been free ever since as he gets a chq back for the feed back amount which covers gas...

He's not the only one!

The issue he has is if something fails, or he wants to upgrade, then he loses that original feedback $ amount and goes onto the latest $ amount

My understanding is that if something dies, & we replace it with the same level of equipment, then the full FiT continues At least, that's in Qld - may be different elsewhere

Dirty prick

You're welcome

[Fizzie]

I don't think that's forever, though.....

2028, unless they change the rules in the meantime