How quickly do solar panels pay for themselves?

I bought my current home about three years ago. I had in mind adding both solar panels and a water tank. The first that I did was the water tank and it has been working well for over two years. However, after it had been installed for a while I compared the water bills before and after and found that, based on the saving that the tank was giving me, it would take about thirty years for it to pay for itself. I hope the tank lasts that long but as I have now passed 70 I am not sure that I will.

This makes me wonder about the solar panels. I have put off installing them because I wonder if they will pay for themselves while I am still in the house. I am also considering the possibility, though there is no definite plan, that I may, for some reason, decide to sell the house before the electricity saving has paid for the panels. If this is the case, I’m wondering how having solar panels affects the selling price of a house. If there were two houses for sale, equal in every other way but one had solar panels, would that one fetch a price that justified having the panels installed?


I installed 8 solar panels 5 years ago and consider it a good deal. The main benefit is that in sunny weather the panels will run one air conditioner plus some. So no consumption much of the time. The feed back tarrif is bad but it helps. Also of course its some contribution to avoiding global warming. Go for it.


A PV panel system can pay for itself in as little as 4 years or less, or it can be much longer, depending on a number of variables.
These include: being at home during the day and timing your loads to make the most of your own power generation reduces the payback time, but being out all day with minimal loads will increase it. Higher FiTs decrease payback time, higher cost per kWh of grid power also reduces it, but higher standing (fixed charge for the connection) charges will increase the time.

The difficulty with having a water tank pay for itself financially is that the standing charges are relatively high, with a low cost per 1000litres charged by some (many/most?) councils, which does not encourage water conservation. Also, having your own source of water and being able to keep your garden alive during periods of severe water restrictions could be worth a lot to some people, but to others worth very little.


Location and timing can play a big role. My 5 kVa/19 panel system should pay for itself in a bit over 2 years - thats a combination of grants that were available at the time, lots of sunshine and local pricing structure per kWh …


I do not intend to be flippant but that snippet reinforces my ‘roo in the headlights’ stance regarding adding solar anything. Even though I understand my use patterns and the pluses and minuses of my roof, Melbourne weather, and utilities costs and projections, the ‘standard expectations for payback ranges’, and so on, it seems the real analysis is a multivariate calculus problem massaged by a ‘fudge factor’ for ‘I am a senior (age, finances, etc) and how long is the future’…


Indeed it is almost impossible to calculate exactly how long a PV system will take to pay for itself… but how about your lounge or fridge, how long did they take to pay themselves off? :wink:


It does not matter because the fridge (and according to my partner the lounge set to keep us sitting off the floor) is essential while solar is still optional. :wink:


I am not aware of such standing charges, there are none for my water tanks. Who charges? What do they charge for? How much? Why?

Solar PV panels have an advantage and a reasonable payback around 3-5years depending on the size installed, but the real savings come from solar/heatpump hot water systems.

I have used solar roof top panels for 30 years and about 5 years ago upgraded the HWS to heat pump model and my annual hot water bill is around $50, whereas if using a standard hot water service it typically would be around $400-$600pa depending on the number of kids home.
Also at the moment if you hunt around you can get new heat pump hot water systems fully installed for less than $100 if you are replacing an old off peak electricity powered HWS.

My point is don’t just consider solar PV’s you have to consider the savings of solar/heatpump hot water.


There are occasionally some great government campaigns. My system is gas storage so I don’t qualify for that one. This commercial site (I have no relationship) with comparative costs (I have not confirmed their rigour but have no reason to suspect them) puts it into perspective that savings need to include amortising the up-front costs, that can be substantial.


The council charges standing charges on water connections to the mains. Check your rates bill.

They charge for access to the water, just like there are standing charges for electricity connections, even if you use none.

I don’t know how much, I’m not on council water.

Because they can.

The point is, no matter how little town water you use, you are still paying the standing charges, this increases the time taken for a water tank to pay for itself. You can’t export water and get paid a FiT like you can with a PV system.

1 Like

I doubt that having a water tank on a suburban block that has town water would be likely to ever pay for itself but I concede for the purpose of discussion it might.

I also doubt that the standing charges for the connection are relevant to the return on the tank. Let us try a thought experiment.

You spend X dollars on a tank and through its use you save Y kilolitres year from the part of your water bill that is charged on consumption. The consumption part of your water bill is charged at Z dollars per kilolitre. So it takes X/Y*Z years to get your money back. The Council or water authority can double or abolish the standing charge and it makes no difference, your payback time on the tank is the same. The standing charges only come into play if you are considering going off the network not if you buy (or don’t buy) a tank.

This is the same as electricity, no matter how much of your consumption you may save or how much power you sell back to the grid you still have the connection fees unless you go off grid.

This leads to the risk of a self-reinforcing decay: a death spiral. The more people defect off grid the fewer that are left to pay the fixed network costs that are inescapable. If the fixed fees of those remaining are increased to cover the loss of defectors’ revenue this makes it more attractive for others to defect, thus leading to more defections. Left to run that way such a network funding system will self destruct. Hopefully our fearless leaders will work out what to do before it gets that bad.


I think this is where you are misunderstanding my point- if the standing charge was removed, the council would increase the cost per kl to maintain revenue. This would improve payback times, as well as encouraging water conservation.

The death spiral of the electricity grid has been discussed for a few years now, and the electricity industry has no one to blame other than themselves… although a bit of government assistance helped them get into this position…


Perhaps if you had said that…

I looked at solar for our home, where we have gas HWS & cooking and the standing charge (service, network fees, minimums etc) forms half our bill. It was not economical, saving about $600 in power and if we paid the $476 to connect to feed into the grid, at $0.04/kwh it would take 11,900 excess kWh to pay that back before we broke even. To feed-in we have to stay on the grid. To go off grid with batteries & generator back-up (cost us $1,400 to have wired into switchboard - power goes off a lot on our SWER), would save us $1,200 pa. but we would lose the $75 rebate for 3 years for signing up for monthly direct debit and the Qld Govt one-off election promised $50 rebate and the Qld Senior’s rebate (which we are still trying to get paid despite being eligible for 3 years). It gets really complicated…

I have a Qld rental house with a young family on a low income with a high electricity bill. I wanted to do something for them, so I am looking at solar. They are part of the widening divide between those who own a roof, who got in early at $0.44/kWh feed in and those who don’t own a roof, like my tenants. The Qld Govt is trialling a scheme for rental properties, but it just seems like a financial arrangement where the Landlord & Tenant share the feed-in, which at that rate would be $0.02/ kWh. Yes, solar adds value to a house, but in my area with falling prices (and I have reduced the rent and provided other cost saving measures) it makes it unattractive. I would be happier to see a Landlord matching grant for rural & remote areas where capital gains are non-existent, rents are low, tenant incomes are low. That is, where it is not possible to justify the expense of solar. In Qld rural & remote means there is only one electricity retailer, and it’s owned by the State Govt.

Before I get painted as a greedy landlord, I bought this near new house specifically to help the community retain the disadvantaged. My tenant earns approx $40k, his partner can’t get work, the local Real Estate agent would not rent a house to them (she considered them too messy - but that’s what little kids do - they grow out of it and he has fixed everything), I helped him get his rent salary sacrificed and (with his help) built garage, sheds, verandahs, replaced equipment with more efficient and reduced his rent. Over 5 years the value of the house has fallen about $150k due to drought, council amalgamation (loss of jobs) etc, but hasn’t helped the rental market, but I rent at approx $100 week less than market rate. He gives a lot back to the community as a volunteer. I cover my costs, but don’t, and won’t make anything out of it.


Ahh but you do get something back, it may not be cash but it will be a better community, likely a lot gratitude to you, and a feeling that you helped. While maybe not as tangible/usable as money they can pay back in other ways.


This depends very much on where you live. We’ve had solar hot water panels for the past 30+ years, and they work really well for us. We are in Brisbane, which helps :slight_smile: .While I have quantified our savings with our PV panels (17.5% return), I havent done the same for the hot water. I do know that we very rarely have to use the electric power booster for the hot water. It’s probably about six months since we required any electric power at all, and that was for maybe a couple of hours after 3-4 days of overcast weather.


Hello Zackarii,

I’m impressed by your selflessness and commitment to your community. I hope other landlords are inspired to follow suit. I have recently read about some companies that are enabling landlords to provide and sell solar to their tenants. I’m not across the details but it’s something you could look into.

Some companies include SunTenants, Allume, Matter, Powerledger and Wattwatchers.

For more information:



And you could explore SonnenFlat which I’m told is also a possibility for landlords. A representative from the company tells me this is especially so when coupled with Natural Solar’s interest free finance, however I have not looked closely at this and cannot make any firm judgment.


We have solar panels and enjoy cheaper power however we mainly installed them on environmental grounds. Think of the world we’ll leave our grandchildren.

1 Like