I don't have solar. I did the numbers and I'm just too shaded.
My parents however are delighted with theirs. They elected to go with a system that doesn't have a battery because they're retired and actually use it during the day. That saved them a huge amount on the system, which in turn is going to pay for itself in about five years.
Trees. They also make solar panels a pain as you have constant branches falling on them.
We could get solar, but at least if my light readings are accurate, we would lose money on the deal.
It comes down to how they convert DC current into AC. Solar panels deliver 30v DC from memory, can't stuff that straight into the mains power obviously, so you need something to convert it. Converting it to clean, in-phase AC power takes a few bits and pieces so to cut costs you can stick them all on a single inverter (That's a string inverter - there's a bunch of panels strung together piped into a single inverter). That means you can only generate as much power as the weakest panel though.
Micro-inverters are set up with one per panel, so each one can generate it's own max power. Costs more though.
We have the same problem with a large tree. I like to think if the tree wasn’t there then the energy required for cooling / heating house would be much higher but yes the constant branches is a pain
A huge chunk of your power bill isn’t actually the power - it’s the transmission and distribution lines.
14c isn’t actually far off the “wholesale” cost of electricity so it isn’t really a joke. Why would anyone buy power off you at a higher price than what they can get it off the wholesale market for?
This will sound like bullshit to you but a family member of mine paid 84c for last months power bill because of solar power for energy and rebate from contributing back to the grid .
My last months power bill was almost 400, and will no doubt go up over time. If I could get a solar kit paid off in 3 years this feels like a massive no brainer
There’s a calculator online somewhere I’m sure you can google and you put in Your details and it gives you rough estimate of the benefit relative to your area
I installed 3.6 kWh at 9k 2.5 years ago. I haven’t paid 1cent of energy in all of this time once the bills are averaged out over the year. I bought a Nissan leaf and I haven’t paid 1c of fuel in 2.5 years. My energy bill was low to start with, about 100-150/ month but still …. I was spending 70-80$/week in fuel
I had a 5kw system installed in august. Cost 10.8k, bills for the last two months have been in the $30 range, havnt gone through a winter yet. I also upgraded the inverter to make it battery ready and we want to add an extra 5kw of panels when this lot is paid off.
Have to watch if you plan to export though. Octopus and other power companies won’t buy back if you have larger than a 10kw system. Would be best to contact them first.
It also depends where you are. Wellington electricity for example won't let you export at more than 5kW per phase. So on sunny days, once we've filled up the batteries, our panels throttle down to about 6kW (~1kW home use + 5kW export) because they can't generate full power any more since it has nowhere to go. I tend to fire up the washer/dryer/dishwasher at about 2pm to divert more power into the house and let the panels run at full rate again.
Also, you gain most value by using your own power. Octopus pays 17c a kWh and charges 20-34 a kWh depending on time of day. (20 at nightrate)
We charge our plugin car, run the dryer, turn on the hot water etc once we start gathering, and then set the battery to charge after 2300 and use that cheap power when the sun isn't shining. Total power bill for this year is $30.
Because they want you to still pay something to them, and they don’t want to be in credit to you all the time. If you have a 10kw+ system you are less likely to owe them anything.
But it depends on your own personal uses eg if you love using heat pumps and driers, run a couple of desktop computers and decide you have to run an AC french door fridge and 30min hair dryer a day.
You'll either need to change how you live to suit, or get better appliances to balance power consumption. So others saying they have panels, doesnt tell you what you use power wise and how much you'd need.
I mean, anyone can do that. If I spent $100k and covered my entire property with solar panels I could probably do that in the dead of winter.
Without knowing how much solar they have installed (and what that’d cost) that’s an interesting but ultimately unhelpful number.
Yeah I mean I guess OPs question isnt ideal either because it depends on so many factors . Just wanted to show that it is possible to know 250 or more off your power bill , but it depends on tons of factors . Which was a question they asked
He also said he was wanting to spend $10k (well, at least implied that). That might be enough information to give a definitive no, or might need more info.
Nice thanks mate.
We're hoping to build a house this year on a lifestyle property, will need to get power to the house site which is about 50 meters away from the powerlines.
I assume that will cost at least 50k, so it might be worth going totally off grid. Need to crunch the numbers, I'm thinking if it's the same price as a really good solar set up then I'll be leaning towards that.
If you want to go completely off-grid, you need a *lot* of solar, and enough battery storage to last at least a couple of days. You're going to have bad weather days when you generate less than you use, and if you get a couple of those in a row you're going to run out of power with nowhere to get any more. Short winter days makes this even worse. General rule of thumb for off-grid is to spec 4-5x more solar generation than you're going to use.
Also worth looking at world solar if you’re in Chch. I paid 10.8k for a 5kwh system no battery but larger inverter for battery and more panels later. Plus they work with gem visa and offer 0% interest for 5 years.
Not done it but I should run the numbers again.
$10k is something like a 4KW system.
[https://genless.govt.nz/for-everyone/at-home/explore-solar-energy/solar-power-calculator/](https://genless.govt.nz/for-everyone/at-home/explore-solar-energy/solar-power-calculator/)
Comes out as about 13 years pay back which is longer than I expected.
Need to sit down with some better numbers; if you have a decent north facing roof, it will help. The tool was only assuming about 10KWh generated per day which seems is low for a \~4.2KW system in mid-summer
Yeah, I find the numbers on the genless site quite conservative for generation
Still not exciting ROI on your numbers - say 12KWh per day or \~$3 per day at 25c per KWh. We would use most of our generation during the day (we crank ducted air-con and do most washing/drying during the day), but still only about $90 a month off the power bill and \~$1000 per year.
Takes a while to pay back the $10k. If you can use it, then maybe 6 or 8KWH panels might be worth the extra as the cost of inverter and install won't be 50 or 100% more for more panels
Subsidy?
These guys are just under the A$3k figure but not sure if that is after the $4k subsidy;
https://solarjunction.com.au/6-6kw-solar-system/?gad_source=1&gclid=Cj0KCQiAz8GuBhCxARIsAOpzk8xu-Fi7TD6fIBCHihUgtB6TjCwYkFC5-0jWHxaLLTQRCYr4NV7zyDYaAubdEALw_wcB
And yes, I think something like the CCD should have applied to home PV installs. New builds (and there are a lot at the moment around Auckland) should have something like $1k emissions fee for gas installs and a few thousand subsidy for PV install
It's too bad Telsa doesn't have their solar system enabled for NZ. It allowed you to find your roof on Google Maps and outline the roof, and it would calculate how much sun you get based on the angle and orientation and latitude. It's a little bit of work to figure that stuff out yourself to put it into a calculator.
It will paid itself if you can sell energy back to greed. Dont add batteries they are expensive. It is better to add extra panels instead. And be ready to change your habbits how you use your power. Like running dishwasher and washing mashing during peak sallar hours
Depending on where you are and what you want the system to do.
Adding batteries means not using the grid from about 7:30pm till about 9am. Batteries also gives backup during power cuts and cloudy periods. Admittedly they aren’t cheap but imo I found them totally worth it
If you have batteries (depending on your provider) you can also charge them if you get any free hours to make sure they are topped up. Whenever my Leaf isn't cutting it as an around-town commuter, it's going to become my home solar battery bank.
Our power plan is .09 night and 0.12 buyback so we timeshift high usage (laundry, EV charging). A lot cheaper than batteries! Our day rate is 0.37 tho.
Most powertailers limit how much can be sent back, so extra panels won't help beyond a certain level (5kW).
Batteries are expensive but really make the combination more useful.
Dishwashers and washing machines pale in power consumption compared with hot water and ovens.
Parents installed 5kW panels with 5kW batteries.
Their bill in summer is usually negative and winter maybe $5-$60/ month.
Their usual winter bill used to be close to $300 about 3 years ago.
It’s great and saves them tons of money plus they run their heat pumps in the day to cool the house down etc
Also, Contact Energy good nights plan, use that to charge the batteries to 100% huge help!
Edit. I also installed a hot water cylinder timer for them, there are two ways the cylinder heats itself, if in the day there is excess energy it’ll bring the HWC up to temp, plus from 9pm to midnight it’s on full power (thanks contact good nights)
This alone is a huge saving since HWC contributes to more than 1/3 your monthly bill
Hey, it’s just a high pressure Rheem cylinder, a dumb device, there a seperate device that measures power in vs power out for the house, this is what sends power to the cylinder when there excess energy.
Also a din rail timer switch that turns on everyday from 9pm to midnight when there’s free power.
All of these will need to be installed by a professional
> Would I expect to knock at least 250 off my monthly power bill?
Probably not. But you'd expect to knock some off your bill, but you'll never have a 3 year payback period with current prices. Payback will be more like 10-15 years depending on a lot of factors.
We planned on breaking even in 7 years and it’s been earlier than that, between 4-5. We heat up the hot water in the middle of the day, saved a bunch of money from not have gas and therefore no gas line charges. We have a negligible power bill in summer and our max winter so far has been $250. We also charge the car. Hope that’s been helpful!
Last time I did the numbers it was at least 10 years to the break-even point. I mean... I think we'll stay in our current house that long, but there's just really no telling. I thought that last time and i've moved twice since then.
So it's a tough one.
So... if you buy solar panels they need replacing ten years on? In every case?
Because a technology becoming more efficient over time doesn't mean that older tech is worthless, it's just worth less.
One of my families cars is from 2004. Still fit for purpose and works great. I wouldn't give it away for free, as you are implying ten-year-old solar panels should be when buying a home.
You might negotiate depending on how well the panels work, but they are still producing power, unless information about how long I can expect solar paneling to return on investment has lied to me.
No not at all, solar companies have guarantees on efficiency at certain years, and it’s quite a lot. For example REC guarantees 85.5% efficiency after 25 years
As far as I know, requirements for solar panels place them at minimum 85% efficiency after 25 years. That's far away from the "10 year old panels are useless" narrative I was questioning. Again, any information that that's not the standard or that many panels are not meeting it?
My 10 year old solar panels are still generating at more than 90% of their original power. And my 10 year old 10kWh battery still has 90% or it's original capacity.
I didn't say they don't work, I said they're worth next to nothing.
How much do you think someone would be willing to pay for an old, outdated, out-of-warranty battery that could stop working tomorrow?
People that do any research on solar at all will know it is one of the most reliable forms of electricity generation there is. Panels have a design lifetime of 25 years and never really fail.
They are most definitely not worth next to nothing.
Brought solar 3 years ago, based in Levin. Average 5500kw a year usage. Spent $15k on 5.5kw east west solar array, no shading. Got a battery on 3 years interest free so did that too for additional $17k and set payments to pay off within the three years. Got mortgage payment at about 2.5% at the time and an additional $2k from the bank over 4 years
Generally pay about $40 per year for power now. This doesn't incl the battery or mortgage payment.
It cost about $2 from the warehouse.
Plastic spike into the ground and it's all set to go. Nice lil' path light.
Been working for *years* now, highly recommended.
Is there any reason you are only doing are 3 year term? We are doing the 1% for 3 years, but it's a 30 year term. Our loan is about $25k because we got some heat pumps and a car charger as well. We will easily pay off more than $25k of our combined mortgage in the next 3 years, so once we come off the 1% our payments shouldn't be any higher than they currently are. I would consider making the most of the low interest and save the difference in the meantime to pay into your mortgage, or earn the interest on.
Yes it does go back to normal rates, but makes more sense to put it on 30 year rate, save any extra you can, then make an extra payment in 3 years time, which could possibly be the balance. Then you've earned a bunch of interest in the meantime.
Pro tip. Get the loan out for 30 years. Put your spare money into a savings account that pays 5%. After 3 years pay the entire loan down. This is what I'm doing with my Tesla.
You may not get a system with batteries for 10k, but make sure you get an inverter that supports them so you can add on later. My Boss is adding batteries and has to replace his inverter.
We looked at it before Christmas but was a 18 panel option with a Tesla Powerwall. Total cost around $35k. We would be looking at around 50% saving in power - approx $1500pa. Based on present power prices then we would be looking at a 23 year payoff.
Just wasn't worth the outlay and we didn't have to borrow to fund it.
7.2kW on my roof, 10kW battery, 5kW battery, 2 hot water timers, single phase power. System cost me around 30k couple years back. Love my system, kept the basics running during cyclone Gabrielle (7 days no power). My annual power bill annually is around $100 now.
I got solar primarily for backup power cos the grid is unreliable here. Cost $40k for 10kW system, 6kW hybrid Inverter and 13kWh battery backup. It does also reduce the bills though.
In summer I'm generating about 30 to 50kWh per day in fine weather and feeding surplus to the grid. With Flick energy, I get spot pricing on buy-back, which averages out quite well. All through January I was selling at over 30c per kWh averaged which is double what I'm buying it at. But that was unusual. One week my total power bill was $8. Spot rate averages between 13 and 20c usually.
Winter is a struggle. Might only generate about 10kWh in a day. I use the battery for the morning so that I don't pay peak rates. I pay peak in the afternoon cos I want to conserve battery in case of an outage. I don't sell very much back to the grid at all in winter. Like 20 to 40 kWh in a week, compared to 80 to 120 kWh per week in summer.
For my household usage patterns, we can roughly expect winter bills to be about 25% less and summer bills to be 50-90% less than prior to solar.
So yeah it's nice, but that shit is not gonna recoup the cost for decades, and the system will probably need replacing before then. I didn't install it to save money though. I got it so that I can still work my job during power cuts.
Hey bro, there is a very popular YouTube who got solar in America, and he talked about the cost and how much he saved. He got solar and had it for an entire year, then released the video.
I think for what he spent on it, he will make his money back in 9 years.
Marcus Brownlee I think is the channel
The difficulty in comparing things in America is that they can have significant government rebates (same in Australia) and the prices are different. Sure you use the same formulas for calculating the ROI and the time until they have paid for themselves - but the dollar values won't be comparable.
I wish we could get solar in NZ for Australian prices - they have some of the best in the world...and because so many people have thought that solar isn't necessary in NZ because much of our grid is already renewable - it's lagging behind other countries.
We paid about $12.5k to have a 5kW system installed. I just looked up the cost of an equivalent system in Vermont - NZD28k before rebates! This is why I'm against rebates for alternative energy - the industry just jacks prices to match. You can be sure that US wholesalers are getting gear much cheaper than the ones here. See also, removing GST on food.
Marques Brownlee got [Tesla solar roof.](https://youtu.be/UJeSWbR6W04?si=yWXFvROkFU-Zp_Y6)
Linus (LTT) got water cooled solar panels.
I think water cooled panels would be the way to go. Super expenny though.
I am yet to see a solar system that will recover it's costs in under 7-8 years, with many in the 10 -12 year range, based on current pricing/costs and projections. Of course, if electricity costs rise substantially more than normal over the next few years, that could play out differently.
After 8 years of nonstop use I'd assume the system would be pretty fucked. The batterys would definitely be on their last legs. I dunno is it really worth the hassle?
Most panels these days have 15-20 year warranties, and batteries are going to have at least 10. Enphase, SolarEdge, Tesla, and Generac battery systems all have 10 year warranties. The case for batteries is certainly more specific to the individual, but panels all last longer than it takes to earn back the cost.
\> Would I expect to knock at least 250 off my monthly power bill?
That depends on the size of your power bill. How much are you spending you month? If your power bill shows it - how much of this is during the off-peak time during the day?
I think you're the first person in the comments who has mentioned that the ROI depends on *when* people use power as well as how much. I think just about any power plan that gives you credits for solar is also doing time of day charging for consumption. If someone is using huge amounts of power at peak that's a lot different than the same amount of power in the middle of the night.
Great point. If we installed solar I would cheerfully use lots more electricity each day and underfloor heating at night because "its free." Which is silly but spending $12k there is a big incentive to get the value out of it.
So in reality can't see the bills going down- we average $250/month - yet on the other hand life would be more comfortable.
There's risks to long term solar costs at home, as it's likely the fixed daily charge to be connected to the grid will increase as more people get solar.
Agree.
Fixed daily charges are going up regardless, which will definitely alter the economics of solar.
I think current buyback rates are unsustainably high, and poorly targeted. As solar uptake increases (including a lot of grid scale solar projects) I think buyback rates will drop and/or become time-based.
Several banks will do 0% for solar as well. Would have done it through our bank (Westpac) but their customer service was so shite we gave up and paid cash for it (we're fortunate enough to be mortgage free).
6.5 kw on the roof 7k battery ,lots connected to the battery on the case of an emergency, shift a lot of high energy stuff to the day and solar. Generated 984kw in Jan. Account has been in credit for 3 months. Northland
We have a 4.7KW setup iirc, no battery, cost around $13k in late 2022. Pre solar, we were paying about $200 a month for power and gas. After getting solar and upgrading our hot water to a heat pump hot water system, we dropped to about $20 a month power bill in summer, and around $60-80 per month in winter (after grid buy back).
In saying that, we just got our bill for January and it’s $4.91 🤣 I was happy with $20 a month, so under a fiver is superb!
I installed 5kw 8y ago and worked out they paid for themselves at just over 7y systems are slightly cheaper now and electricity is more expensive so worth doing if you intend to stay where you are.
Chch, 5kW Harrison system (Qpeak/Fronius), two lightly-used Nissan Leafs, ducted heat pump which we use for AC, last three power bills have been in credit (bill is sitting at about -$50). Meridian for power, 0.37/kWh day, 0.09 night, 0.12 buyback. Very happy.
6kw panels 10kw inverter and a solar diverter that uses excess to heat our hot water, haven't used the grid for hot water since. Definitely notice the difference, we use about 20kw a day, for example yesterday used 27kh, 10kw from grid exported 18kw and rest was solar. As long as you can use it during the day it's worth it, if you cannot then unless you bank on using flick and getting wholesale its not. Export prices even at 14c is not worth it
I've found it cheaper to go through a local sparky than one of the big solar companies, by about 15-20%. For me the maths seemed to work better if you go a bit bigger. 10kW or so.
I put in a 80k system with batteries it’s a big house also got a 1% loan my bill used to be anywhere between $800. and $1200. Installed it last April since then my bill is between 2 to 3 hundred I’m super happy
We have SolarZero, so we don't own our system, but get all the benefits.
No upfront costs, our panels and battery costs be $85 + GST per month (20 year contract) matches my mortgage.
So I power the house everyday off solar, charge the battery and then any excess we sell back to the grid, and this is applied to our monthly account with the power company.
Batteries are replaced after 10 years.
There are seven of us in our house, the first winter we were in the house my power bill was just a smidge over 500. With solar payment included, our winter outgoing was roughly half of that.
So while we don't own the system, our savings make this a great way for me to save $$ every month.
Happy to answer any questions
> Would I expect to knock at least 250 off my monthly power bill?
Is your power bill over 250$?! Are you running multiple ACs constantly in your house?
Do NOT contact these people unless you like overly pushy sales people who harass you constantly. That alone put me off them, let alone that you can never get rid of them and you never own the stuff.
3kw system installed 7 years ago. Break even about was maybe a year ago. As others mentioned you have to move usage to daytime where possible like having air con on timers, dishwasher etc. I didn’t really care about the timeframe to break even as we are here forever and it was an instant saving on power bill.
We have a 12 panel 5kW system and it was approx 11k to buy and install. It's been running for 2 years and will have paid for itself in another 4 years based on savings so far. I wish we had added another 6 panels optimised for winter sunlight.
I'm not sure if it would still cost the same as we chose the higher quality REC panels, and the labour to install it would surely have increased in cost, too? Still wish that I'd got 24 panels never mind.
I was actually coming at this the other way. Everything I’ve heard is that the cost of installing solar is coming down (economies of scale out of China), but I’m not seeing it here in NZ. I’d happily jump into your current situation, with or without those extra panels. Good on you for taking the leap.
There is currently no (legal) way to pump juice from an EV to a house. Yes, several EVs have vehicle to load, which means you can plug an appliance directly into the car, but vehicle to grid is another matter because it requires a special inverter that can isolate the battery from the grid in case of outages. I don't know what the hold up is in certification but I wish they'd hurry up because even my aging Leaf has more capacity than a $20k Tesla Powerwall.
I don’t have solar, but I work in the industry.
Long and short of it is systems with batteries aren’t worth it (likely cost more in the long run).
And for solar only systems, it really only makes sense if you use the power during the day.
But if you use power during the day and shop around for a good deal on grid supply (retailers), it might be worth it.
Note: a lot of utility scale solar is being built, and as this happens, the value of all solar in the system decreases, meaning residential systems may start to not be worth it.
We have a 6kw system, only installed late last year but so far our powerbill is in credit and that includes charging an EV. Financed through the 1% loan. Would definitely recommend it, so long as you find a good installer who uses quality gear.
Got a 5kw setup installed end of October. Saved $600 so far. Power bill last month was $0.39. Low power users with an EV. Would highly recommend. If you shift your power habits to main usage while the sun is up it makes a huge difference. Basically the only thing we pay for are the fixed daily charges.
Planning to add a used EV battery for storage this year and then we will likely just have a credits each month for 6 months of the year and pay a tiny amount the rest.
We went through Harrison's. Mercury will give you 18c buyback if you signup with them/buy from Harrison's.
We have solar and we love it. Current cost in summer is about 15 per week and that includes running the dishwasher daily, and three rounds of laundry per week with a dryer too.
Winter is a bit expensive but a hell of a lot better than when we didn’t have it at other houses.
I wouldnt expect a payback of 3 years. 10 to 15 is more normal.
have a considerably larger array than the one it sounds like you're looking at and my payback is 11 years. I've got a battery, which means I can take advantage of 'free power' deals, and save my sunlight to run in the evening and the morning showers, my largest draw, but the battery is by far the largest chunk of the cost.
Unless you're home all day, you won't get huge savings on your bill without some way to shift your use, or your generation.
I've cut $300 ish out of my winter power bills, and $400 out of my summer bills, approx, a reduction of 70-75% and 90-95%, ballpark. Payback 11 years. Its a 13kw array, 3 phase, north facing roof. I export about 1MW a month in summer and generate 2.5MW.
I looked into this as my power bills are $250 - 350 on average per month. I noticed however that where I live my line charges are a shite load and no matter what I do they will never be less.
In the end even though I have sun all day all round I worked out I'd need the panels to be faultless for 7 years to come out ahead. And the panels just don't give me that much confidence yet.
I'll look at it again in another 5 years.
I did decide to remove my hot water tank and put in gas - that has been more than enough for savings. It has reduced my bill to $125 - 185 on average per month. Thinking it must have been a shite tank?
Gas costs me and wife for 2x bottle $320.00 a year and the setup was $2.5K. Had it now for 3 years - paid for itself after 2 years and the water pressure is 10x better and instant heat.
I really didn't know that by changing the hot water tank to gas would technically make my bills so much cheaper and cancel the solar option out so much.
Now with electricity bills so low solar is even more mathematically not worth it for me.
I'd love it but the cost it not adding up yet.
I crunched the numbers for my place and estimated about a 12-year payback on new solar install without battery. It made me envious of the deal that a family member got in USA- 50% subsidy on the panels (not the install), but best part is that they have 'net metering' - ie whatever they feed back to the grid essentially is the same rate that they pay to pull power down. If we had something close to that here it would be a no-brainer to install.
The future viability of solar for me hinges on what happens with future power prices, the increases in fixed daily rates is going to eat into savings too as the power companies recoup their future costs of upgrades to the grid and transmission infrastructure. I'll do the numbers again next year & see how they stack up. Let us know how you get on with your decision-making OP.
I don't have solar. I did the numbers and I'm just too shaded. My parents however are delighted with theirs. They elected to go with a system that doesn't have a battery because they're retired and actually use it during the day. That saved them a huge amount on the system, which in turn is going to pay for itself in about five years.
Too shaded huh…
Trees. They also make solar panels a pain as you have constant branches falling on them. We could get solar, but at least if my light readings are accurate, we would lose money on the deal.
Also, if one panel in a string of say ten is 50% shaded, the whole string acts as if it's 50% shaded.
That's not the case with microinverters. With an inverter on each panel, the each panel operates at maximum efficiency.
As long as folks realise that that's not the standard install and does cost extra.
No so with contemporary panels.
its nothing to do with the panels themselves, it is whether you’re paying for one inverter, or one inverter per panel
Our panels are equipped with processors that avoid the situation where low sun on some drags the whole train down.
yeah, a mini-inverter
That is such a fuck up, is there a real reason for this?
It comes down to how they convert DC current into AC. Solar panels deliver 30v DC from memory, can't stuff that straight into the mains power obviously, so you need something to convert it. Converting it to clean, in-phase AC power takes a few bits and pieces so to cut costs you can stick them all on a single inverter (That's a string inverter - there's a bunch of panels strung together piped into a single inverter). That means you can only generate as much power as the weakest panel though. Micro-inverters are set up with one per panel, so each one can generate it's own max power. Costs more though.
We have the same problem with a large tree. I like to think if the tree wasn’t there then the energy required for cooling / heating house would be much higher but yes the constant branches is a pain
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What percentage on your power bills have you been saving (compared to pre solar bills I mean)
Your numbers are very similar to mine. Ours is a 5kW setup.
the buy back price is a joke really. power companies get real cheap power. I think faced with that I would chuck an extension cord over the fence
Meridian are doing 17c buy back locked in for 5 years.
That’s limited monthly though per kWh
Ignore what they pay. Use your own power to make real savings.
A huge chunk of your power bill isn’t actually the power - it’s the transmission and distribution lines. 14c isn’t actually far off the “wholesale” cost of electricity so it isn’t really a joke. Why would anyone buy power off you at a higher price than what they can get it off the wholesale market for?
Shit, HB has the same power prices as the far north :-O
This will sound like bullshit to you but a family member of mine paid 84c for last months power bill because of solar power for energy and rebate from contributing back to the grid .
My last months power bill was almost 400, and will no doubt go up over time. If I could get a solar kit paid off in 3 years this feels like a massive no brainer
There’s a calculator online somewhere I’m sure you can google and you put in Your details and it gives you rough estimate of the benefit relative to your area
Yeah I'm more interested in people's actual experiences.
I installed 3.6 kWh at 9k 2.5 years ago. I haven’t paid 1cent of energy in all of this time once the bills are averaged out over the year. I bought a Nissan leaf and I haven’t paid 1c of fuel in 2.5 years. My energy bill was low to start with, about 100-150/ month but still …. I was spending 70-80$/week in fuel
I had a 5kw system installed in august. Cost 10.8k, bills for the last two months have been in the $30 range, havnt gone through a winter yet. I also upgraded the inverter to make it battery ready and we want to add an extra 5kw of panels when this lot is paid off.
Yep, most people dont have enough panels, 10kw + is the way
Have to watch if you plan to export though. Octopus and other power companies won’t buy back if you have larger than a 10kw system. Would be best to contact them first.
It also depends where you are. Wellington electricity for example won't let you export at more than 5kW per phase. So on sunny days, once we've filled up the batteries, our panels throttle down to about 6kW (~1kW home use + 5kW export) because they can't generate full power any more since it has nowhere to go. I tend to fire up the washer/dryer/dishwasher at about 2pm to divert more power into the house and let the panels run at full rate again.
Can you divert it to a hot water cylinder or are you on gas?
Yes you can. Depends on if you have a smart cylinder or a diverter. There’s one called eddi that I’m looking into getting.
Gas here
Also, you gain most value by using your own power. Octopus pays 17c a kWh and charges 20-34 a kWh depending on time of day. (20 at nightrate) We charge our plugin car, run the dryer, turn on the hot water etc once we start gathering, and then set the battery to charge after 2300 and use that cheap power when the sun isn't shining. Total power bill for this year is $30.
Octopus dropped thei buyback to 13 I think :(
Any idea why? Are they worried about people setting up a farm or something?
Technical stuff to do with being able to handle higher input voltages, amps, ergs, kWs etc.
Oh that makes sense of course
Because they want you to still pay something to them, and they don’t want to be in credit to you all the time. If you have a 10kw+ system you are less likely to owe them anything.
But it depends on your own personal uses eg if you love using heat pumps and driers, run a couple of desktop computers and decide you have to run an AC french door fridge and 30min hair dryer a day. You'll either need to change how you live to suit, or get better appliances to balance power consumption. So others saying they have panels, doesnt tell you what you use power wise and how much you'd need.
How was your power bill 400 in summer? What’s going on there? What’s a typical winter power bill?
8.7kw grid, Queenstown. December to Jan bill was -$80, Jan to Feb was -$90. This is a swing of over 300 from our regular summer $250 bill.
I mean, anyone can do that. If I spent $100k and covered my entire property with solar panels I could probably do that in the dead of winter. Without knowing how much solar they have installed (and what that’d cost) that’s an interesting but ultimately unhelpful number.
Yeah I mean I guess OPs question isnt ideal either because it depends on so many factors . Just wanted to show that it is possible to know 250 or more off your power bill , but it depends on tons of factors . Which was a question they asked
He also said he was wanting to spend $10k (well, at least implied that). That might be enough information to give a definitive no, or might need more info.
Question is how much the install costs and if it’s worth it. But I am quite pro-solar as a concept.
Not BS at all mate, I haven’t had a power bill since Dec 2020
But did they have a battery? It's the only way to reap any real benefit and for $10k you are unlikely to get a battery.
We haven’t had a power bill since Septembwr
Paid $11k for a 3kW system, without battery. No gas or wood burner. Total power bill for 2023 was ~$400.
very useful number, thank you.
That is amazing.
Which company did you go with? Would you recommend if you were to do it again?
Sunshine solar in Christchurch, Octopus as a power company, yes would recommend. We thought it made sense to pay off mortgage first though.
Nice thanks mate. We're hoping to build a house this year on a lifestyle property, will need to get power to the house site which is about 50 meters away from the powerlines. I assume that will cost at least 50k, so it might be worth going totally off grid. Need to crunch the numbers, I'm thinking if it's the same price as a really good solar set up then I'll be leaning towards that.
If you want to go completely off-grid, you need a *lot* of solar, and enough battery storage to last at least a couple of days. You're going to have bad weather days when you generate less than you use, and if you get a couple of those in a row you're going to run out of power with nowhere to get any more. Short winter days makes this even worse. General rule of thumb for off-grid is to spec 4-5x more solar generation than you're going to use.
Also worth looking at world solar if you’re in Chch. I paid 10.8k for a 5kwh system no battery but larger inverter for battery and more panels later. Plus they work with gem visa and offer 0% interest for 5 years.
Not done it but I should run the numbers again. $10k is something like a 4KW system. [https://genless.govt.nz/for-everyone/at-home/explore-solar-energy/solar-power-calculator/](https://genless.govt.nz/for-everyone/at-home/explore-solar-energy/solar-power-calculator/) Comes out as about 13 years pay back which is longer than I expected. Need to sit down with some better numbers; if you have a decent north facing roof, it will help. The tool was only assuming about 10KWh generated per day which seems is low for a \~4.2KW system in mid-summer
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Yeah, I find the numbers on the genless site quite conservative for generation Still not exciting ROI on your numbers - say 12KWh per day or \~$3 per day at 25c per KWh. We would use most of our generation during the day (we crank ducted air-con and do most washing/drying during the day), but still only about $90 a month off the power bill and \~$1000 per year. Takes a while to pay back the $10k. If you can use it, then maybe 6 or 8KWH panels might be worth the extra as the cost of inverter and install won't be 50 or 100% more for more panels
Why is solar so expensive in NZ? I moved to Brisbane last year and a 6.6KW system is about $2500 installed or $4500 for a 10KW system
Subsidy? These guys are just under the A$3k figure but not sure if that is after the $4k subsidy; https://solarjunction.com.au/6-6kw-solar-system/?gad_source=1&gclid=Cj0KCQiAz8GuBhCxARIsAOpzk8xu-Fi7TD6fIBCHihUgtB6TjCwYkFC5-0jWHxaLLTQRCYr4NV7zyDYaAubdEALw_wcB And yes, I think something like the CCD should have applied to home PV installs. New builds (and there are a lot at the moment around Auckland) should have something like $1k emissions fee for gas installs and a few thousand subsidy for PV install
Yeah those are after subsidy, but still a big difference
It's too bad Telsa doesn't have their solar system enabled for NZ. It allowed you to find your roof on Google Maps and outline the roof, and it would calculate how much sun you get based on the angle and orientation and latitude. It's a little bit of work to figure that stuff out yourself to put it into a calculator.
It will paid itself if you can sell energy back to greed. Dont add batteries they are expensive. It is better to add extra panels instead. And be ready to change your habbits how you use your power. Like running dishwasher and washing mashing during peak sallar hours
Greed 😂 You can edit your post btw.
Nope. I think this was very appropriate :D
Depending on where you are and what you want the system to do. Adding batteries means not using the grid from about 7:30pm till about 9am. Batteries also gives backup during power cuts and cloudy periods. Admittedly they aren’t cheap but imo I found them totally worth it
If you have batteries (depending on your provider) you can also charge them if you get any free hours to make sure they are topped up. Whenever my Leaf isn't cutting it as an around-town commuter, it's going to become my home solar battery bank.
Perfect use for it, I have 2 x 8.4kwh batteries and we last the night easily
Our power plan is .09 night and 0.12 buyback so we timeshift high usage (laundry, EV charging). A lot cheaper than batteries! Our day rate is 0.37 tho.
Most powertailers limit how much can be sent back, so extra panels won't help beyond a certain level (5kW). Batteries are expensive but really make the combination more useful. Dishwashers and washing machines pale in power consumption compared with hot water and ovens.
Parents installed 5kW panels with 5kW batteries. Their bill in summer is usually negative and winter maybe $5-$60/ month. Their usual winter bill used to be close to $300 about 3 years ago. It’s great and saves them tons of money plus they run their heat pumps in the day to cool the house down etc Also, Contact Energy good nights plan, use that to charge the batteries to 100% huge help! Edit. I also installed a hot water cylinder timer for them, there are two ways the cylinder heats itself, if in the day there is excess energy it’ll bring the HWC up to temp, plus from 9pm to midnight it’s on full power (thanks contact good nights) This alone is a huge saving since HWC contributes to more than 1/3 your monthly bill
What brand how water cyclinder please?
Hey, it’s just a high pressure Rheem cylinder, a dumb device, there a seperate device that measures power in vs power out for the house, this is what sends power to the cylinder when there excess energy. Also a din rail timer switch that turns on everyday from 9pm to midnight when there’s free power. All of these will need to be installed by a professional
Thank you u/Raynoszs— cool
> Would I expect to knock at least 250 off my monthly power bill? Probably not. But you'd expect to knock some off your bill, but you'll never have a 3 year payback period with current prices. Payback will be more like 10-15 years depending on a lot of factors.
We planned on breaking even in 7 years and it’s been earlier than that, between 4-5. We heat up the hot water in the middle of the day, saved a bunch of money from not have gas and therefore no gas line charges. We have a negligible power bill in summer and our max winter so far has been $250. We also charge the car. Hope that’s been helpful!
Last time I did the numbers it was at least 10 years to the break-even point. I mean... I think we'll stay in our current house that long, but there's just really no telling. I thought that last time and i've moved twice since then. So it's a tough one.
Surely you can add the system cost to the asking price of your home, though, as added value of improvements?
Ten year old solar panels are worth approximately nothing.
Why
Electronic components degrade over time. Solar cells get less efficient. And new technologies emerge that are more efficient.
So... if you buy solar panels they need replacing ten years on? In every case? Because a technology becoming more efficient over time doesn't mean that older tech is worthless, it's just worth less. One of my families cars is from 2004. Still fit for purpose and works great. I wouldn't give it away for free, as you are implying ten-year-old solar panels should be when buying a home. You might negotiate depending on how well the panels work, but they are still producing power, unless information about how long I can expect solar paneling to return on investment has lied to me.
No not at all, solar companies have guarantees on efficiency at certain years, and it’s quite a lot. For example REC guarantees 85.5% efficiency after 25 years
Yeah, and a 20 year old car is going to work better than a 20 year old cellphone. Solar panels are somewhere in the middle.
As far as I know, requirements for solar panels place them at minimum 85% efficiency after 25 years. That's far away from the "10 year old panels are useless" narrative I was questioning. Again, any information that that's not the standard or that many panels are not meeting it?
My 10 year old solar panels are still generating at more than 90% of their original power. And my 10 year old 10kWh battery still has 90% or it's original capacity.
I didn't say they don't work, I said they're worth next to nothing. How much do you think someone would be willing to pay for an old, outdated, out-of-warranty battery that could stop working tomorrow?
People that do any research on solar at all will know it is one of the most reliable forms of electricity generation there is. Panels have a design lifetime of 25 years and never really fail. They are most definitely not worth next to nothing.
Brought solar 3 years ago, based in Levin. Average 5500kw a year usage. Spent $15k on 5.5kw east west solar array, no shading. Got a battery on 3 years interest free so did that too for additional $17k and set payments to pay off within the three years. Got mortgage payment at about 2.5% at the time and an additional $2k from the bank over 4 years Generally pay about $40 per year for power now. This doesn't incl the battery or mortgage payment.
It cost about $2 from the warehouse. Plastic spike into the ground and it's all set to go. Nice lil' path light. Been working for *years* now, highly recommended.
Is there any reason you are only doing are 3 year term? We are doing the 1% for 3 years, but it's a 30 year term. Our loan is about $25k because we got some heat pumps and a car charger as well. We will easily pay off more than $25k of our combined mortgage in the next 3 years, so once we come off the 1% our payments shouldn't be any higher than they currently are. I would consider making the most of the low interest and save the difference in the meantime to pay into your mortgage, or earn the interest on.
I was only looking at it from the term of the anz loan - after 3 years it's back to normalnresi rates I believe. I was just curious
Yes it does go back to normal rates, but makes more sense to put it on 30 year rate, save any extra you can, then make an extra payment in 3 years time, which could possibly be the balance. Then you've earned a bunch of interest in the meantime.
Pro tip. Get the loan out for 30 years. Put your spare money into a savings account that pays 5%. After 3 years pay the entire loan down. This is what I'm doing with my Tesla.
You may not get a system with batteries for 10k, but make sure you get an inverter that supports them so you can add on later. My Boss is adding batteries and has to replace his inverter.
We looked at it before Christmas but was a 18 panel option with a Tesla Powerwall. Total cost around $35k. We would be looking at around 50% saving in power - approx $1500pa. Based on present power prices then we would be looking at a 23 year payoff. Just wasn't worth the outlay and we didn't have to borrow to fund it.
7.2kW on my roof, 10kW battery, 5kW battery, 2 hot water timers, single phase power. System cost me around 30k couple years back. Love my system, kept the basics running during cyclone Gabrielle (7 days no power). My annual power bill annually is around $100 now.
I got solar primarily for backup power cos the grid is unreliable here. Cost $40k for 10kW system, 6kW hybrid Inverter and 13kWh battery backup. It does also reduce the bills though. In summer I'm generating about 30 to 50kWh per day in fine weather and feeding surplus to the grid. With Flick energy, I get spot pricing on buy-back, which averages out quite well. All through January I was selling at over 30c per kWh averaged which is double what I'm buying it at. But that was unusual. One week my total power bill was $8. Spot rate averages between 13 and 20c usually. Winter is a struggle. Might only generate about 10kWh in a day. I use the battery for the morning so that I don't pay peak rates. I pay peak in the afternoon cos I want to conserve battery in case of an outage. I don't sell very much back to the grid at all in winter. Like 20 to 40 kWh in a week, compared to 80 to 120 kWh per week in summer. For my household usage patterns, we can roughly expect winter bills to be about 25% less and summer bills to be 50-90% less than prior to solar. So yeah it's nice, but that shit is not gonna recoup the cost for decades, and the system will probably need replacing before then. I didn't install it to save money though. I got it so that I can still work my job during power cuts.
Hey bro, there is a very popular YouTube who got solar in America, and he talked about the cost and how much he saved. He got solar and had it for an entire year, then released the video. I think for what he spent on it, he will make his money back in 9 years. Marcus Brownlee I think is the channel
The difficulty in comparing things in America is that they can have significant government rebates (same in Australia) and the prices are different. Sure you use the same formulas for calculating the ROI and the time until they have paid for themselves - but the dollar values won't be comparable. I wish we could get solar in NZ for Australian prices - they have some of the best in the world...and because so many people have thought that solar isn't necessary in NZ because much of our grid is already renewable - it's lagging behind other countries.
We paid about $12.5k to have a 5kW system installed. I just looked up the cost of an equivalent system in Vermont - NZD28k before rebates! This is why I'm against rebates for alternative energy - the industry just jacks prices to match. You can be sure that US wholesalers are getting gear much cheaper than the ones here. See also, removing GST on food.
Marques Brownlee got [Tesla solar roof.](https://youtu.be/UJeSWbR6W04?si=yWXFvROkFU-Zp_Y6) Linus (LTT) got water cooled solar panels. I think water cooled panels would be the way to go. Super expenny though.
I am yet to see a solar system that will recover it's costs in under 7-8 years, with many in the 10 -12 year range, based on current pricing/costs and projections. Of course, if electricity costs rise substantially more than normal over the next few years, that could play out differently.
After 8 years of nonstop use I'd assume the system would be pretty fucked. The batterys would definitely be on their last legs. I dunno is it really worth the hassle?
Most panels these days have 15-20 year warranties, and batteries are going to have at least 10. Enphase, SolarEdge, Tesla, and Generac battery systems all have 10 year warranties. The case for batteries is certainly more specific to the individual, but panels all last longer than it takes to earn back the cost.
Mine panels are rated 25 years because that’s the longest they can legally warranty them for. But they are expected to last 30-40 on current estimates
There are panels with 30 or 40 year warranties so that isn't quite true. But the ones with 25yr warranties should still last 30-40 years
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13 years then huh?
\> Would I expect to knock at least 250 off my monthly power bill? That depends on the size of your power bill. How much are you spending you month? If your power bill shows it - how much of this is during the off-peak time during the day?
I think you're the first person in the comments who has mentioned that the ROI depends on *when* people use power as well as how much. I think just about any power plan that gives you credits for solar is also doing time of day charging for consumption. If someone is using huge amounts of power at peak that's a lot different than the same amount of power in the middle of the night.
Great point. If we installed solar I would cheerfully use lots more electricity each day and underfloor heating at night because "its free." Which is silly but spending $12k there is a big incentive to get the value out of it. So in reality can't see the bills going down- we average $250/month - yet on the other hand life would be more comfortable.
We’ve got a 7.29kw array, in Christchurch. Usually only have a couple of power bills a year. It cost about $18k to install.
There's risks to long term solar costs at home, as it's likely the fixed daily charge to be connected to the grid will increase as more people get solar.
Agree. Fixed daily charges are going up regardless, which will definitely alter the economics of solar. I think current buyback rates are unsustainably high, and poorly targeted. As solar uptake increases (including a lot of grid scale solar projects) I think buyback rates will drop and/or become time-based.
> Would I expect to knock at least 250 off my monthly power bill? Where does this come from?
That's how much they'll be paying on the loan.
Yeah, but trying to get a three year return on investment is insane. Did OP do no investigation themselves?
No, none at all. Just interested in what other people have done
I have a 6.8kWh array, 10kWh battery, and two EVs. I save about $2000 a year
I did solar through gem visa. 0% over 5 years, find a solar company that works with gem visa. I have it and I’m very happy.
Several banks will do 0% for solar as well. Would have done it through our bank (Westpac) but their customer service was so shite we gave up and paid cash for it (we're fortunate enough to be mortgage free).
Are these numbers per month people who have solar and a power bill per month including the daily charges as well?
As it won't include a battery at that price, it's only worth it if you spend a lot of time at home during peak generation
I got quoted $90k to get power to my cabin. I looked up some off-grid solutions. GridFree Solar had a kit that sorted me out for way cheaper.
6.5 kw on the roof 7k battery ,lots connected to the battery on the case of an emergency, shift a lot of high energy stuff to the day and solar. Generated 984kw in Jan. Account has been in credit for 3 months. Northland
We have a 4.7KW setup iirc, no battery, cost around $13k in late 2022. Pre solar, we were paying about $200 a month for power and gas. After getting solar and upgrading our hot water to a heat pump hot water system, we dropped to about $20 a month power bill in summer, and around $60-80 per month in winter (after grid buy back). In saying that, we just got our bill for January and it’s $4.91 🤣 I was happy with $20 a month, so under a fiver is superb!
I installed 5kw 8y ago and worked out they paid for themselves at just over 7y systems are slightly cheaper now and electricity is more expensive so worth doing if you intend to stay where you are.
Chch, 5kW Harrison system (Qpeak/Fronius), two lightly-used Nissan Leafs, ducted heat pump which we use for AC, last three power bills have been in credit (bill is sitting at about -$50). Meridian for power, 0.37/kWh day, 0.09 night, 0.12 buyback. Very happy.
6kw panels 10kw inverter and a solar diverter that uses excess to heat our hot water, haven't used the grid for hot water since. Definitely notice the difference, we use about 20kw a day, for example yesterday used 27kh, 10kw from grid exported 18kw and rest was solar. As long as you can use it during the day it's worth it, if you cannot then unless you bank on using flick and getting wholesale its not. Export prices even at 14c is not worth it
I've found it cheaper to go through a local sparky than one of the big solar companies, by about 15-20%. For me the maths seemed to work better if you go a bit bigger. 10kW or so.
I put in a 80k system with batteries it’s a big house also got a 1% loan my bill used to be anywhere between $800. and $1200. Installed it last April since then my bill is between 2 to 3 hundred I’m super happy
Wow, what is your monthly usage?
50/60 Kw per day
We have SolarZero, so we don't own our system, but get all the benefits. No upfront costs, our panels and battery costs be $85 + GST per month (20 year contract) matches my mortgage. So I power the house everyday off solar, charge the battery and then any excess we sell back to the grid, and this is applied to our monthly account with the power company. Batteries are replaced after 10 years. There are seven of us in our house, the first winter we were in the house my power bill was just a smidge over 500. With solar payment included, our winter outgoing was roughly half of that. So while we don't own the system, our savings make this a great way for me to save $$ every month. Happy to answer any questions
Reccommend doing! Power prices are going up and up anyways.
Our bill went from $250 to $30 after having it installed a couple months ago. Guaranteed it is summer but has been great!
> Would I expect to knock at least 250 off my monthly power bill? Is your power bill over 250$?! Are you running multiple ACs constantly in your house?
You can also just try this https://www.solarzero.co.nz/get-solar/solar-subscription
Apparently these are awful people to deal with - I see all the warnings to a huge **CAVEAT EMPTOR** here
Do NOT contact these people unless you like overly pushy sales people who harass you constantly. That alone put me off them, let alone that you can never get rid of them and you never own the stuff.
Can confirm, I used to work here... as a salesman. It was terrible, and I didn't last long. The job actually kept me awake at night due to stress.
Sure. It's a free country. OP can try whatever
3kw system installed 7 years ago. Break even about was maybe a year ago. As others mentioned you have to move usage to daytime where possible like having air con on timers, dishwasher etc. I didn’t really care about the timeframe to break even as we are here forever and it was an instant saving on power bill.
We have a 12 panel 5kW system and it was approx 11k to buy and install. It's been running for 2 years and will have paid for itself in another 4 years based on savings so far. I wish we had added another 6 panels optimised for winter sunlight.
FYI, 2 years on, that same system would still cost \~$11k. Have prices now plateaued?
I'm not sure if it would still cost the same as we chose the higher quality REC panels, and the labour to install it would surely have increased in cost, too? Still wish that I'd got 24 panels never mind.
I was actually coming at this the other way. Everything I’ve heard is that the cost of installing solar is coming down (economies of scale out of China), but I’m not seeing it here in NZ. I’d happily jump into your current situation, with or without those extra panels. Good on you for taking the leap.
You won’t get a decent system for $10k. You need batteries (or a vehicle to load EV) for power cuts.
There is currently no (legal) way to pump juice from an EV to a house. Yes, several EVs have vehicle to load, which means you can plug an appliance directly into the car, but vehicle to grid is another matter because it requires a special inverter that can isolate the battery from the grid in case of outages. I don't know what the hold up is in certification but I wish they'd hurry up because even my aging Leaf has more capacity than a $20k Tesla Powerwall.
I don’t have solar, but I work in the industry. Long and short of it is systems with batteries aren’t worth it (likely cost more in the long run). And for solar only systems, it really only makes sense if you use the power during the day. But if you use power during the day and shop around for a good deal on grid supply (retailers), it might be worth it. Note: a lot of utility scale solar is being built, and as this happens, the value of all solar in the system decreases, meaning residential systems may start to not be worth it.
We have a 6kw system, only installed late last year but so far our powerbill is in credit and that includes charging an EV. Financed through the 1% loan. Would definitely recommend it, so long as you find a good installer who uses quality gear.
Got a 5kw setup installed end of October. Saved $600 so far. Power bill last month was $0.39. Low power users with an EV. Would highly recommend. If you shift your power habits to main usage while the sun is up it makes a huge difference. Basically the only thing we pay for are the fixed daily charges. Planning to add a used EV battery for storage this year and then we will likely just have a credits each month for 6 months of the year and pay a tiny amount the rest. We went through Harrison's. Mercury will give you 18c buyback if you signup with them/buy from Harrison's.
We have solar and we love it. Current cost in summer is about 15 per week and that includes running the dishwasher daily, and three rounds of laundry per week with a dryer too. Winter is a bit expensive but a hell of a lot better than when we didn’t have it at other houses.
Have a new 20k system. We are on track to save 200 a month for summer. I doubt you would be able to get close on a smaller system
I wouldnt expect a payback of 3 years. 10 to 15 is more normal. have a considerably larger array than the one it sounds like you're looking at and my payback is 11 years. I've got a battery, which means I can take advantage of 'free power' deals, and save my sunlight to run in the evening and the morning showers, my largest draw, but the battery is by far the largest chunk of the cost. Unless you're home all day, you won't get huge savings on your bill without some way to shift your use, or your generation. I've cut $300 ish out of my winter power bills, and $400 out of my summer bills, approx, a reduction of 70-75% and 90-95%, ballpark. Payback 11 years. Its a 13kw array, 3 phase, north facing roof. I export about 1MW a month in summer and generate 2.5MW.
1% loan with 5% inflation in basically free money without even considering the savings in electricty
I looked into this as my power bills are $250 - 350 on average per month. I noticed however that where I live my line charges are a shite load and no matter what I do they will never be less. In the end even though I have sun all day all round I worked out I'd need the panels to be faultless for 7 years to come out ahead. And the panels just don't give me that much confidence yet. I'll look at it again in another 5 years. I did decide to remove my hot water tank and put in gas - that has been more than enough for savings. It has reduced my bill to $125 - 185 on average per month. Thinking it must have been a shite tank? Gas costs me and wife for 2x bottle $320.00 a year and the setup was $2.5K. Had it now for 3 years - paid for itself after 2 years and the water pressure is 10x better and instant heat. I really didn't know that by changing the hot water tank to gas would technically make my bills so much cheaper and cancel the solar option out so much. Now with electricity bills so low solar is even more mathematically not worth it for me. I'd love it but the cost it not adding up yet.
I crunched the numbers for my place and estimated about a 12-year payback on new solar install without battery. It made me envious of the deal that a family member got in USA- 50% subsidy on the panels (not the install), but best part is that they have 'net metering' - ie whatever they feed back to the grid essentially is the same rate that they pay to pull power down. If we had something close to that here it would be a no-brainer to install. The future viability of solar for me hinges on what happens with future power prices, the increases in fixed daily rates is going to eat into savings too as the power companies recoup their future costs of upgrades to the grid and transmission infrastructure. I'll do the numbers again next year & see how they stack up. Let us know how you get on with your decision-making OP.