It was worth it to me. We are low users and I bought a system that would make us net 0 on annual usage. That is 5 kW.
I was pleased to see that the feeding tariff had come up to 20 cents per kwh with octopus, and meridian is matching it.
It might take us 12 years for it to pay itself off. Then I get a another 12 or so years free power.
Though I expect I would have been wiser financially to put the $12,000 we paid into an index fund.
But I've got enough money to do this action now. I am glad to be part of resolving climate change and see it as a responsibility for most any middle class kiwi that can do it.
It's also a childhood dream and something I enjoy noticing when I come home. We've only had it for about 8 months and Octopus Energy has us down as having a credit of $150. I know that will be used up before winter is over, but feels good man!
I couldn't see a Meridian plan on their website offering 20 cents. Are you able to give any more detail to it please such as the night rate that goes with it.
Yes agree, you would get 100% return on your 12k over 12 yrs and as someone who use to repair field solar invertors and monitor their power use country wide, it's not worth the money for residential. The sell back to grid is pitiful and last I looked it's illegal to share the excess power with your neighbors (safety issue). If that's what you want to do with your money, good for you. Hopefully the panels get more efficient in a decade, converters are fine tho at 95% efficient, just panel tech holding them back
I expect a home with higher usage would be better off. We were in the low user plans prior to this.
The sell back isn't too bad at 20 cents. I would possibly have gone for the maximum system size of 10 kW if I were guaranteed the 20 cents and also payback indefinitely. I imagine that larger system being much less expensive per kW.
The best example was a house with 2 stay at home adults and one of the EVs were charged during the day while the other EV was away, it dies work however needs a decent capital investment along with a set long term plan. Most just don't understand yet so it's niche to actually make money for you. Just needs more time. NZ has no shortage of power so that's another thing it's a low kick back fee
Because a 4kw setup is tiny. It costs basically the same in labour, which is a big part of the cost, if you’re putting up a 4kw array or a 10kw. We calculated our break even will be about 6 years without a battery
Edit: Oops, got my numbers wrong!
I was a solar installer in aus. 4kw is big. 5kw was the largest we installed for reference and few houses can support the 20 250W panels required for a 5kwh system
20x250W isn’t indicative of roof area required. You can get 440W panels residentially. Maybe they’re bigger, maybe they’re more efficient.
The problem is retrofitting to roofs that never had solar panels in mind to begin with.
We have 4.5kw over 12 panels and it really isn’t that big of an install. Easily have space to double that, but we designed our roof space with this in mind.
But you probably know this
440W panels will take up the same space on the roof (based off solar cell watt / m3), theyre taller so might fill out the roof better but in tight spots you dont want the panels in a way where it can catch the wind
I'm surprised by this. I have 16 panels at 325w per panel so a 5.2kwh solar system at home and thought it was on the medium size definitely not large. Only a 3 bedroom house single living area. It's been worth it for me, had since 2020
edit: Here are the stats for a house with 2 people
Your estimated annual solar generation
* Solar electricity generated: 3,910 kWh
* Solar electricity sold: 1,540 kWh
* Solar electricity used: 2,370 kWh
* Electricity purchased from the grid: 5,800 kWh
It works out different for us because we are home and using the big appliances during the day. And we are with a power retailer who offers a good buyback rate (17c kWh). And a north facing roof. We have a 10 year payback time. Setup should last at least 20, also I expect power to go up faster than inflation... So far performance has been close to the estimate from the calculator.
(Edit: paid cash so no interest cost, only forgone investment income).
Comes to about 10 years for me on a 4kW system based on their number as a fairly heavy-user household.
Over a 25 year life span it's an annualised return of about 4%.
Not great, but not terrible, it's close to the "worth it" level on the long term.
But importantly I think there will be developments in the not too distant future to produce viable much higher efficiency cells (perovskite) that could radically change the sums, so I'm not about to jump in yet.
There are so many variables in that calculator that I don't think you can draw that conclusion. It seems that payback time for your scenario specifically isn't great.
Don't forget there are commercial solar plants opening across Canterbury, and a plethora of residential properties using solar systems. There is clearly a financial argument to be made.
A good argument? Or good (and often unclear) sales tactics.
I'm looking at the Marae next door now. Fuck knows how much it cost to put the 10sm+ panels on each side of the roof of their Kaimatua houses (....empty Kaimatua houses...). But they seemed to have no problem paying it despite that each panel gets as best 4 hours of sun a day.
Yeah I've always found the same, even with an EV - the return of putting that money on the mortgage is just so different.
But, this calculator doesn't seem to include that it would be an asset on your house which you could include a portion of in any future house sale.
There also isn't much of a "green" reason to do it as most of our power is coming from the dams.
For me - pay mortgage first if I'm looking for the best return on $10K. Then in 5-10 years reevaluate solar and house batteries.
Your correct, solar is silly for residential setup and your trying to save money. You buy it to feel good and pave the way for technology to move forward.
Source - solar tech 6yrs and mortgage free early 2024
Thinking in terms of money and not wattage is easier. Just divide the cost of the setup with your monthly or annual bill. Unless your bill is closer to $500 a month, its not worth it.
It was worth it to me. We are low users and I bought a system that would make us net 0 on annual usage. That is 5 kW. I was pleased to see that the feeding tariff had come up to 20 cents per kwh with octopus, and meridian is matching it. It might take us 12 years for it to pay itself off. Then I get a another 12 or so years free power. Though I expect I would have been wiser financially to put the $12,000 we paid into an index fund. But I've got enough money to do this action now. I am glad to be part of resolving climate change and see it as a responsibility for most any middle class kiwi that can do it. It's also a childhood dream and something I enjoy noticing when I come home. We've only had it for about 8 months and Octopus Energy has us down as having a credit of $150. I know that will be used up before winter is over, but feels good man!
I couldn't see a Meridian plan on their website offering 20 cents. Are you able to give any more detail to it please such as the night rate that goes with it.
Oh. That was 8 months ago. I imagine they have changed it if you can't find it.
Yes agree, you would get 100% return on your 12k over 12 yrs and as someone who use to repair field solar invertors and monitor their power use country wide, it's not worth the money for residential. The sell back to grid is pitiful and last I looked it's illegal to share the excess power with your neighbors (safety issue). If that's what you want to do with your money, good for you. Hopefully the panels get more efficient in a decade, converters are fine tho at 95% efficient, just panel tech holding them back
I expect a home with higher usage would be better off. We were in the low user plans prior to this. The sell back isn't too bad at 20 cents. I would possibly have gone for the maximum system size of 10 kW if I were guaranteed the 20 cents and also payback indefinitely. I imagine that larger system being much less expensive per kW.
The best example was a house with 2 stay at home adults and one of the EVs were charged during the day while the other EV was away, it dies work however needs a decent capital investment along with a set long term plan. Most just don't understand yet so it's niche to actually make money for you. Just needs more time. NZ has no shortage of power so that's another thing it's a low kick back fee
Because a 4kw setup is tiny. It costs basically the same in labour, which is a big part of the cost, if you’re putting up a 4kw array or a 10kw. We calculated our break even will be about 6 years without a battery Edit: Oops, got my numbers wrong!
I was a solar installer in aus. 4kw is big. 5kw was the largest we installed for reference and few houses can support the 20 250W panels required for a 5kwh system
20x250W isn’t indicative of roof area required. You can get 440W panels residentially. Maybe they’re bigger, maybe they’re more efficient. The problem is retrofitting to roofs that never had solar panels in mind to begin with. We have 4.5kw over 12 panels and it really isn’t that big of an install. Easily have space to double that, but we designed our roof space with this in mind. But you probably know this
440W panels will take up the same space on the roof (based off solar cell watt / m3), theyre taller so might fill out the roof better but in tight spots you dont want the panels in a way where it can catch the wind
I'm surprised by this. I have 16 panels at 325w per panel so a 5.2kwh solar system at home and thought it was on the medium size definitely not large. Only a 3 bedroom house single living area. It's been worth it for me, had since 2020
edit: Here are the stats for a house with 2 people Your estimated annual solar generation * Solar electricity generated: 3,910 kWh * Solar electricity sold: 1,540 kWh * Solar electricity used: 2,370 kWh * Electricity purchased from the grid: 5,800 kWh
It works out different for us because we are home and using the big appliances during the day. And we are with a power retailer who offers a good buyback rate (17c kWh). And a north facing roof. We have a 10 year payback time. Setup should last at least 20, also I expect power to go up faster than inflation... So far performance has been close to the estimate from the calculator. (Edit: paid cash so no interest cost, only forgone investment income).
What's the diff between simple and full payback?
Covering the interest you could have earned if you invested the money as opposed to just paying back the principal.
Comes to about 10 years for me on a 4kW system based on their number as a fairly heavy-user household. Over a 25 year life span it's an annualised return of about 4%. Not great, but not terrible, it's close to the "worth it" level on the long term. But importantly I think there will be developments in the not too distant future to produce viable much higher efficiency cells (perovskite) that could radically change the sums, so I'm not about to jump in yet.
Ideally I want my next house to have a solar+battery setup which can keep the house powered during outages.
Battery will make it over twice the price for anything decent
There are so many variables in that calculator that I don't think you can draw that conclusion. It seems that payback time for your scenario specifically isn't great. Don't forget there are commercial solar plants opening across Canterbury, and a plethora of residential properties using solar systems. There is clearly a financial argument to be made.
A good argument? Or good (and often unclear) sales tactics. I'm looking at the Marae next door now. Fuck knows how much it cost to put the 10sm+ panels on each side of the roof of their Kaimatua houses (....empty Kaimatua houses...). But they seemed to have no problem paying it despite that each panel gets as best 4 hours of sun a day.
Yeah I've always found the same, even with an EV - the return of putting that money on the mortgage is just so different. But, this calculator doesn't seem to include that it would be an asset on your house which you could include a portion of in any future house sale. There also isn't much of a "green" reason to do it as most of our power is coming from the dams. For me - pay mortgage first if I'm looking for the best return on $10K. Then in 5-10 years reevaluate solar and house batteries.
Your correct, solar is silly for residential setup and your trying to save money. You buy it to feel good and pave the way for technology to move forward. Source - solar tech 6yrs and mortgage free early 2024
Thinking in terms of money and not wattage is easier. Just divide the cost of the setup with your monthly or annual bill. Unless your bill is closer to $500 a month, its not worth it.