Solar Predicted v Actual Benefit, and Install Reliability

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Ispofdoom

3 posts

Wannabe Geek

#307036 13-Sep-2023 21:16

Hi Geekzone,

I've been looking into the cost-benefits of getting solar installed for the past month or so.
If you have solar, I'd like to know how the actual generation has gone for you, and whether you are on track to break even. If it isn't going well, what happened?

My gut feeling is that solar installers can vary a lot in quality of work. What was your install like? What should I look for in a good install (particularly around safety)?

We are considering a Rec /Fronius setup through Future Energy. Has anyone got any experience with them?

Thanks in advance

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398 posts

Ultimate Geek

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#3127536 14-Sep-2023 08:57

We went with Harrison, REC Alpha + Fronius (~5kW no battery).

Performance wise they've done well, probably slightly higher than I expected the first year and very close to what the installer thought they did. This year though with the wet first 3-4 months they did noticeably worse (just not enough sun). On track to break even, though the exact break even date depends exactly on what deals one can get on power prices. The better deal you can get the better the longer time to break even, the more the power company is screwing you or your region over the quicker they pay for them selves (massive difference if you are paying 19c/kWh vs 30c/kWh).

dacraka

766 posts

Ultimate Geek

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#3129702 20-Sep-2023 12:55

I have installed solar and batteries (one year ago now).

I have now realised that if I put the amount of cost into my investments instead, it would have benefitted me significantly greater and faster.

Investments cannot protect you in a power-cut, however.

tripper1000

1617 posts

Uber Geek

#3129764 20-Sep-2023 14:00

Safety-wise, panels are installed to a fairly stringent ANZS, and inverters have to be NZ certified, so it mostly comes down to quality of workmanship after that.

Payback-wise, it not only depends on import/export rates but can also depends a lot on you and your consumption habits and installation add-on's. Generally there are big and overlooked ROI opportunities by maximising the amount of self generated power that you consume. E.G. using self generated power as you make it so as to minimise selling it in the day time for ~9 cents only to buy it back at ~28 cents in the evening. For instance, setting timers on dishwasher and washing machines etc to run the day time and installing a solar-diverter that dynamically modulates power sent to your hot water cylinder to minimise the power sent back to/taken from the grid as clouds block the sun and as other loads switch on and off.

Edit: For me (modest 3kw system), I did it more because I was a curious geek and less for savings. Earnings from solar alone were very minimal until I hooked it up to the hot water, then I started to notice ~ $30 savings on my power bill.

deadlyllama

1264 posts

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#3129773 20-Sep-2023 14:43

Our installer told us that batteries completely destroyed the RoI. Without batteries, our projected RoI was about 10% per year.

But - looking at putting in an ex-Leaf battery ... watch this space. The lower cost of the ex-Leaf battery makes the RoI look much better.

In general I'm extremely happy with our installer, solarsupplies.co.nz - Ross knows his stuff. Other installers were some combination of being clearly salespeople with limited knowledge of what they sold, unable to visit ths site, unable to begin the install in a reasonable amount of time, or insisting on a battery that pushed the cost up massively. Also the big guys aren't going to be interested in helping me attach an old Leaf battery to the inverter :P

Quinny

885 posts

Ultimate Geek

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#3130523 22-Sep-2023 15:07

Harrisons, Solaredge, LG Panels, Tesla Powerwall. 3 years in and love it still. Zero regrets. I paid 36k and well worth every cent. Upped house value and also means power less than 3000 units a year for an electronics nuts household. Still check the Tesla app almost every day. In Chch area.

MartinGZ

359 posts

Ultimate Geek

Subscriber

#3130578 22-Sep-2023 17:17

Quinny:

Harrisons, Solaredge, LG Panels, Tesla Powerwall. 3 years in and love it still. Zero regrets. I paid 36k and well worth every cent. Upped house value and also means power less than 3000 units a year for an electronics nuts household. Still check the Tesla app almost every day. In Chch area.

But one of the things that the OP asked was "whether you are on track to break even". Have you tracked your energy use for some years both before and after installation and worked out the payback? Graphs of 12 month moving totalled data can quickly show drop in exported energy, but in my view you'd want at least a couple of years before and after to do it properly. It's always nice to see lower bills, but I'd query the economics - $36k is a lot of capital to return.

Wombat1

586 posts

Ultimate Geek
Inactive user

#3130598 22-Sep-2023 17:52

it all depends on where you live, in Wellington for example I would never even think about adding solar onto our house there (maybe wind turbines would be better). Here in Brisbane we have so many sunshine hours that it is actually silly not to have solar.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

fe31nz

1232 posts

Uber Geek

#3130780 22-Sep-2023 22:49

Wombat1:

it all depends on where you live, in Wellington for example I would never even think about adding solar onto our house there (maybe wind turbines would be better). Here in Brisbane we have so many sunshine hours that it is actually silly not to have solar.

Wellington's sunshine hours are actually pretty decent: 2050 (the same as Auckland). Not as much as Brisbane though (2750), but still easily enough for solar panels to be good. The journalists seem to talk down Wellington's sun hours without actually checking the facts, and then the general public follows that. But it is just not true that Wellington lacks sun. And while wind turbines might seem to be a good idea in Wellington (and they are), most wind turbines have a maximum speed that they can not safely exceed, so they feather the blades or apply brakes when the wind speed is too high. So you actually do not get to use a lot of the higher speed wind available in places like Wellington.

Wombat1

586 posts

Ultimate Geek
Inactive user

#3131036 23-Sep-2023 17:03

fe31nz:

Wombat1:

it all depends on where you live, in Wellington for example I would never even think about adding solar onto our house there (maybe wind turbines would be better). Here in Brisbane we have so many sunshine hours that it is actually silly not to have solar.

Wellington's sunshine hours are actually pretty decent: 2050 (the same as Auckland). Not as much as Brisbane though (2750), but still easily enough for solar panels to be good. The journalists seem to talk down Wellington's sun hours without actually checking the facts, and then the general public follows that. But it is just not true that Wellington lacks sun. And while wind turbines might seem to be a good idea in Wellington (and they are), most wind turbines have a maximum speed that they can not safely exceed, so they feather the blades or apply brakes when the wind speed is too high. So you actually do not get to use a lot of the higher speed wind available in places like Wellington.

There are other factors too which should be taken into account, sunlight intensity, length of days, Sun Incidence Angle etc ... Generally the closer you are to the equator the better your solar generation. A sunny day in Auckland is going to generate a little more energy than a sunny day in Invercargill (all things equal for the same amount of hours). Asking the question about actual benefit and the time to pay it off depends on so many factors that its not easily going to be answered here unless we get more info from the op.

"Breaking even" in a place like Invercargil will take a very long time, your panels and batteries may even need to be replaced before that time. ALso it depends on your electrical supplier, and how much they charge you for power, and how much you get for topping up the grid.... too many factors.

Goosey

2834 posts

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#3131207 24-Sep-2023 10:31

Anyone needed to re roof first or after panels installed?

- what’s the panel installation like in terms of type of roof required vs anything that may be problematic?

Ispofdoom

3 posts

Wannabe Geek

#3131319 24-Sep-2023 15:13

Hi all,
OP here. Thanks for the responses. Some really good info and great to have feedback from owners before shelling out hard earned money for our own system.

We've ended up going with Harrison, Rec Alpha + Fronius. No battery as the ROI didn't make sense. We went with the premium options even though the payback period seems to be around 7 years as we intend to stay in this house for 10+ years it makes financial sense to pay a bit more now to get reliable returns further down the line.

For us it was a really close decision between Harrisons and Future Energy. Price wise they were very similar, reviews were good for both (but not perfect). Both use their own installation teams, which is good as one concern I had is to sign up and then get sub-contracted out to someone/some company I hadn't been able to conduct due diligence on. Both gave the full warranty on the equipment (Rec - 25 yr performance, product and labour, Fronius 10 year).

To address a few comments:
dacraka - I get where you're coming from regarding better returns through investment, but hindsight is a perfect investment advisor. We're also looking at solar to increase cashflow in a few years time when our kids are older.

tripper1000 - we're going to start adopting timers on dishwasher, etc. We'll be on Mercury with an 18c buyback rate for 2 years. After that we might switch to Octopus which will definitely need timers and careful management of time of day electricity usage. In a similar way to you - I'll also admit that there is an element of me being a curious geek wanting to explore solar. Is anybody with Octopus? It's a mission to calculate usage and generation based on the peak/off-peak/night-time rates but it looks like it might be worth changing too once we're done with Mercury.

deadlyllama - very keen to hear how the ex-Leaf battery goes for home use. Would this meet NZ standards and could it get a code of compliance? How many bars would you look for (or how much remaining capacity?) We have a leaf that gets around 90 km on an 80% charge. There's plenty of life in it for what we want, but at some point it may make more sense to convert to a household battery.

Quinny - sounds like a fantastic setup! I wish we could have gone for the Tesla Powerwall but we didn't have the funds available and I couldn't make the ROI work. Have you experienced any degradation on the equipment? (Battery storage capacity, panel efficiency, etc)

Wombat1 - good points, and one of the biggest headaches I had with all this is that you have to really get into detail or make a ton of assumptions when calculating the financials.

Goosey - we've just been through a renovation in the past few years so our roof is fairly new. From what I gathered getting multiple quotes corrugated steel roofs are one of the easier types. Whereas concrete/decramastic tiles are tricky to install on due to the brittle material. Worth sending photos or getting someone out to have a look if you're concerned this may be an issue for you.

Quinny

885 posts

Ultimate Geek

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#3131659 25-Sep-2023 13:29

Ispofdoom:

Hi all,
OP here. Thanks for the responses. Some really good info and great to have feedback from owners before shelling out hard earned money for our own system.

...

Quinny - sounds like a fantastic setup! I wish we could have gone for the Tesla Powerwall but we didn't have the funds available and I couldn't make the ROI work. Have you experienced any degradation on the equipment? (Battery storage capacity, panel efficiency, etc)

I went for the LG Neon2 as the degradation was less than 3% at 10 years, warranty 25 years. Shame can no longer get these. I built a battleship and made same choices as you for same reasons.

Couple of people have looked at ROI as only x spent vs y saved. I also considered that according to my app I have generated just under 30 MWh in 3 years, fake planted the equivalent of 325 tress and saved 52000 kg of C02 emissions. This makes me feel good. Powerwalll wise I can use the Genesis Power shouts to top up the system (or with Contact the 3 free hours) - there are many options you can use to fill the powerwall for bad days.

We are off grid or close (the house uses about 25 kWh a day) from about September to March and other than mid winter I find power bills fun not stressful. I am always using the Tesla and Genesis apps even now 3 years later.

The value of the system QV happily added to my rateable value (also make sure you do the same with your insurance as has to be listed to be covered I found). I

My ROI has been briliant - the value on the RV in full, reduced power bills by 75% a year, the feel good/green factor getting a big tick. As with anything if its just numbers then year it can take a while (6-10 for solar, double with Powerwall) but when you add in the Powerwall the system is just so good. YMMV of course :)

BlargHonk

147 posts

Master Geek

#3131661 25-Sep-2023 13:53

Quinny:

Ispofdoom:

Hi all,
OP here. Thanks for the responses. Some really good info and great to have feedback from owners before shelling out hard earned money for our own system.

...

Quinny - sounds like a fantastic setup! I wish we could have gone for the Tesla Powerwall but we didn't have the funds available and I couldn't make the ROI work. Have you experienced any degradation on the equipment? (Battery storage capacity, panel efficiency, etc)

I went for the LG Neon2 as the degradation was less than 3% at 10 years, warranty 25 years. Shame can no longer get these. I built a battleship and made same choices as you for same reasons.

Couple of people have looked at ROI as only x spent vs y saved. I also considered that according to my app I have generated just under 30 MWh in 3 years, fake planted the equivalent of 325 tress and saved 52000 kg of C02 emissions. This makes me feel good. Powerwalll wise I can use the Genesis Power shouts to top up the system (or with Contact the 3 free hours) - there are many options you can use to fill the powerwall for bad days.

We are off grid or close (the house uses about 25 kWh a day) from about September to March and other than mid winter I find power bills fun not stressful. I am always using the Tesla and Genesis apps even now 3 years later.

The value of the system QV happily added to my rateable value (also make sure you do the same with your insurance as has to be listed to be covered I found). I

My ROI has been briliant - the value on the RV in full, reduced power bills by 75% a year, the feel good/green factor getting a big tick. As with anything if its just numbers then year it can take a while (6-10 for solar, double with Powerwall) but when you add in the Powerwall the system is just so good. YMMV of course :)

What is the advantage of getting QV to add it to the rateable value of your house? Isn't that just what the council uses to set your rates?

dahc

33 posts

Geek

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Lifetime subscriber

#3131666 25-Sep-2023 14:20

Ispofdoom:

...

We've ended up going with Harrison, Rec Alpha + Fronius. No battery as the ROI didn't make sense. We went with the premium options even though the payback period seems to be around 7 years as we intend to stay in this house for 10+ years it makes financial sense to pay a bit more now to get reliable returns further down the line.

I purchased Fronius (6kW) + REC TwinPeak 4 Series (7.4kW) and like yourself, I couldn't justify the additional expense of a battery. I've just come off 12 months of use and if I was to take this as an average I would have an ROI of eight years. Being that summer in Auckland was pretty sub-par, I'm ok with that as a baseline.

Quinny

885 posts

Ultimate Geek

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#3131675 25-Sep-2023 14:56

BlargHonk:

What is the advantage of getting QV to add it to the rateable value of your house? Isn't that just what the council uses to set your rates?

Ever live in Chch and have your house written off? I do and did. It goes on the RV :)

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