3kW Grid Tied Solar PV: Watts and Warts.

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#1154249 15-Oct-2014 10:55

$12K seems like a big investment to save $1200 per year. That's ten years payback, not counting the time value of money which probably makes it closer to 12 or 15 years (ie you could earn interest on money not spent). Add in maintenance and replacement parts and it doesn't seem like it's ready for people who purely want to save money long term. There are other benefits of course, the green thing, having power in an outage (though they seem to mostly be at night around here, when everyone turns heat pumps on).

SumnerBoy

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#1154257 15-Oct-2014 10:58

Yes - but the lifetime of these panels should be around 30yrs - they have a guarantee of 90% production at 25yrs - so if you look at the long term picture, after your 12-15yr payback has finished you are saving that $1200 a year. So over the lifetime (30yrs) you are somewhere between $18K-$20K in the black - and that is assuming electricity prices don't rise.

It certainly isn't a short term win, but over the long term it stacks up pretty well.

wellygary

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#1154276 15-Oct-2014 11:03

SumnerBoy: Yes - but the lifetime of these panels should be around 30yrs - they have a guarantee of 90% production at 25yrs - so if you look at the long term picture, after your 12-15yr payback has finished you are saving that $1200 a year. So over the lifetime (30yrs) you are somewhere between $18K-$20K in the black - and that is assuming electricity prices don't rise.

But that assumes that you don't move,

Solar's great if you are staying put, but for many people at an early stage of life, the $$$ simply dont stack up unless they are prepared to commit to an specific house for 15 yrs+

SumnerBoy

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#1154279 15-Oct-2014 11:05

Totally - assumes you will be in that house for the whole time. Not for everyone of course, but for those of us building their family home they intend to live in for a long time, it is almost a no brainer.

Porboynz

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#1154284 15-Oct-2014 11:10

timmmay: $12K seems like a big investment to save $1200 per year. That's ten years payback, not counting the time value of money which probably makes it closer to 12 or 15 years (ie you could earn interest on money not spent). Add in maintenance and replacement parts and it doesn't seem like it's ready for people who purely want to save money long term. There are other benefits of course, the green thing, having power in an outage (though they seem to mostly be at night around here, when everyone turns heat pumps on).

You are absolutely 100% right, but that's not the main point for me. Just a few observations though:
- If the power goes off a grid tied PV system shuts down immediately to stop it from exporting power into wires that might have linesmen working on them.
- The price of power is not static
- The Kiwibank loan is essentially interest free, but yes I still have to repay $12k over the 5 year term at about $220 per month
- Maintenance and replacement parts is a concern, I will be annoyed if the Inverter fails after its 5 year warranty, not so concerned about the panels
- Your tagline mentions "Lots and lots of Nikon camera gear ", well I have a Galaxy 3 and a Panasonic point and shoot that take photos just fine.

Just kidding you, my point is we do things that interest us and this interest looks like it will be self funding, eventually. (Maybe you earn from your photography as well?)

timmmay

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#1154304 15-Oct-2014 11:31

Porboynz: Just kidding you, my point is we do things that interest us and this interest looks like it will be self funding, eventually. (Maybe you earn from your photography as well?)

True, like I said there are many reasons, but it's probably not ready for the mainstream quite yet IMHO. And yeah my photographer gear has paid for itself many many times over.

gchiu

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#1154367 15-Oct-2014 12:46

timmmay: $12K seems like a big investment to save $1200 per year.

I see a Nelson crowd offering a 3kW package for $7200. Doesn't say if it includes installation or GST though.

freemark

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#1154392 15-Oct-2014 12:54

Plenty of people spend $15k on a new bathroom or kitchen without even thinking of "payback"

timmmay

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#1154404 15-Oct-2014 13:10

freemark: Plenty of people spend $15k on a new bathroom or kitchen without even thinking of "payback"

I guess both solar panels and a new bathroom would add value to a house when it's sold - though a $15K bathroom is relatively cheap in my experience. I'm just saying that economically solar power's value is questionable and not yet for everyone.

I'd quite like solar power with some storage myself, just because it sounds like a good idea. Without storage I doubt I'd get much benefit, most of our power use is after it gets dark and selling back to the power companies seems of limited value.

freemark

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#1154412 15-Oct-2014 13:26

timmmay:
freemark: Plenty of people spend $15k on a new bathroom or kitchen without even thinking of "payback"

I guess both solar panels and a new bathroom would add value to a house when it's sold - though a $15K bathroom is relatively cheap in my experience. I'm just saying that economically solar power's value is questionable and not yet for everyone.

I'd quite like solar power with some storage myself, just because it sounds like a good idea. Without storage I doubt I'd get much benefit, most of our power use is after it gets dark and selling back to the power companies seems of limited value.

Yeah, well if you really want to blow some cash get some storage currently. My thinking is that we are at least 3 years away from anywhere near cost effective solutions there.. but with a good power plant on your roof you'll be ready for it - and have started to recoup the cost of that power plant.

mclean

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#1155575 15-Oct-2014 17:31

freemark: Plenty of people spend $15k on a new bathroom or kitchen without even thinking of "payback"

The payback from spending on a new bathroom or kitchen is that you get a new bathroom or kitchen. That's a real benefit for sure.

The only payback you might (or might not) get from solar generation is a financial one. The electricity at the socket is the same. Except maybe a feel-good factor.

freemark

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#1155576 15-Oct-2014 17:33

mclean:
freemark: Plenty of people spend $15k on a new bathroom or kitchen without even thinking of "payback"

The payback from spending on a new bathroom or kitchen is that you get a new bathroom or kitchen. That's a real benefit for sure.

The only payback you might (or might not) get from solar generation is a financial one. The electricity at the socket is the same. Except maybe a feel-good factor.

Oh well maybe you should be on the kitchen or bathroom Forum...

gchiu

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#1155592 15-Oct-2014 18:00

There is a definite payback on reduced CO2 emissions.

Ouranos

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#1155604 15-Oct-2014 18:36

gchiu: There is a definite payback on reduced CO2 emissions.

Given the current European carbon price is about NZD$10/tonne of CO2, and CO2 production of 0.1 kg/kWh, the saving from a 3kW PV system is about $5 pa. Not much of a payback.

gchiu

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#1155624 15-Oct-2014 19:10

Paying someone $5 does not make the tonne of CO2 disappear, but the PV array does.

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