Solar Panels - Worth it ?, Do they last long enough ?.

[Peter Sarf]

I have often wondered about solar panels. I have over the years bought various solar powered devices and within a few years or less I have found they no longer work. My latest - an ultrasonic animal repeller has stopped working within 12 months. It can be charged from an external supply but no joy so maybe not the solar panel but the battery.

Anyway I have often wondered about solar panels on the roof to power our home. How long will they work for I have wondered as I need to work out the total savings to balance against the cost. I have just seen this article and it stokes my fear that solar panels might not actually be worth it. Furthermore they seem to be an ecological mess as recycling them is difficult.

Here is the link to the article, its a bit badly written so leads me to think it is open to interpretation. It got a bit repetitive towards the end so I might have missed something.

How long will YOUR solar panels last? Millions will soon face the cost of replacing their eco-roof tiles... and most will be scrapped because there's only ONE place to recycle them in UK​

Tonnes of solar panels could end up on the scrap heap unless the Government acts now, experts have warned.

There are around 25million solar panels in the UK and as 2.5billion globally.

Governments across the world, the UK included, have been pushing for green alternatives to fossil fuels in order to hit emission targets in a bid to tackle climate change.

But as the first generation of solar panels are expected to die off in the coming years, experts have warned that many could end up in landfill rather than recycled because of a drastic lack of infrastructure.

Currently, there is only one recycling plant in the whole of the UK that specialises in recycling solar panels but this is a small operation in Scunthorpe.

However, the company is currently only stockpiling the panels and when they have 'enough stock' then they will 'invest in the equipment to recycle them', a spokesman told Mail Online, adding that it was 'early days in the industry'.

The only place in the entire world that will recycle solar panels on an industrial scale is the first Return of Silicon Plant (ROSI) in France, which was due to open last month.

(Two pictures of solar panels on roofs)

At the moment, the number of dead solar panels is only a small scale.

But the first generation of solar panels is forecast to die within the next five or ten years and according to Professor Chris Sansom at the University of Derby, by 2050 we could have 300 million tonnes of scrap panels globally.

I was wondering what other people might already know ?.

MODS - I hope I am OK linking this ?.

 

[Tazi Hupefi]

Huge difference between solar panels on your roof and properly wired into the mains etc - versus a Chinese gadget from the internet, local garden centre etc that essentially contains a cheap rechargeable battery and I wouldn't expect to last more than 12 months when purchasing.

You should get 25 years out of most modern solar panels, I suspect properly maintained you'd get 30+. I've had mine for 4 years and they're absolutely fine. When they got fitted, I asked the question and apparently they could theoretically keep going for 50, but nobody knows yet obviously. I costed on the basis of 25, anything beyond that is a bonus.

 

[Bevan Price]

Huge difference between solar panels on your roof and properly wired into the mains etc - versus a Chinese gadget from the internet, local garden centre etc that essentially contains a cheap rechargeable battery and I wouldn't expect to last more than 12 months when purchasing.

You should get 25 years out of most modern solar panels, I suspect properly maintained you'd get 30+. I've had mine for 4 years and they're absolutely fine. When they got fitted, I asked the question and apparently they could theoretically keep going for 50, but nobody knows yet obviously. I costed on the basis of 25, anything beyond that is a bonus.

In most of UK, solar power is insufficient to keep batteries recharged throughout the year - the daylight intensity is insufficient to recharge batteries on days like today (5 August), and too short during winter. You need to take batteries out of the device occasionally, and recharge them using a decent reliable battery charger (e.g. one that can distinguish between Lithium-Metal Hydride and other battery types).

 

[Peter Sarf]

In most of UK, solar power is insufficient to keep batteries recharged throughout the year - the daylight intensity is insufficient to recharge batteries on days like today (5 August), and too short during winter. You need to take batteries out of the device occasionally, and recharge them using a decent reliable battery charger (e.g. one that can distinguish between Lithium-Metal Hydride and other battery types).

Yes. That is why I went for an animal repeller that could be re-charged from an outside source.

== Doublepost prevention - post automatically merged: 5 Aug 2023 ==

Huge difference between solar panels on your roof and properly wired into the mains etc - versus a Chinese gadget from the internet, local garden centre etc that essentially contains a cheap rechargeable battery and I wouldn't expect to last more than 12 months when purchasing.

You should get 25 years out of most modern solar panels, I suspect properly maintained you'd get 30+. I've had mine for 4 years and they're absolutely fine. When they got fitted, I asked the question and apparently they could theoretically keep going for 50, but nobody knows yet obviously. I costed on the basis of 25, anything beyond that is a bonus.

Indeed I would hope the solar panels for the roof would be better made. I was a bit alarmed by the report. I must admit I was hoping for payback in less than 25 years.

I am thinking perhaps the money would be better spent on insulation (foam on the outside of the walls as no cavity) as that stands to save more per year then solar panels, has a lot less to go wrong and probably last a lot longer. Downside could be flammability. That way using less energy in the first place rather than hoping to generate it cheaply.

 

[Tazi Hupefi]

Yes. That is why I went for an animal repeller that could be re-charged from an outside source.

== Doublepost prevention - post automatically merged: 5 Aug 2023 ==


Indeed I would hope the solar panels for the roof would be better made. I was a bit alarmed by the report. I must admit I was hoping for payback in less than 25 years.

I am thinking perhaps the money would be better spent on insulation (foam on the outside of the walls as no cavity) as that stands to save more per year then solar panels, has a lot less to go wrong and probably last a lot longer. Downside could be flammability. That way using less energy in the first place rather than hoping to generate it cheaply.

Not sure where abouts you reside, but insulation does/can have downsides in terms of trapping heat - it can be a bad thing in summer, especially as it is getting warmer each year, present one excepted. If you are thinking of the fairly long term, it is a necessary consideration. I've found that new build houses can be extremely uncomfortable in summer but very warm and pleasant in winter.

I have quite energy efficient air conditioning (hot and cold) which is cost effective to run because it is largely powered by solar / solar charged home batteries.

 

[adc82140]

I've had solar panels for about a year. Forget battery storage, that's expensive with a lifespan of about 10 years. My outlay was just over £7000 for a 3.6kW system. That includes an Eddi device to divert excess to the hot water tank. This time of year I'm generally exporting back to the grid after about 11am, with a completely heated up water tank.

My total energy bill last month was minus £56. Yes really I was paid 56 quid by my provider. Taking in to account my total consumption I am saving about £300 a month. Obviously during the winter that reduces, last year January I paid about £80 for energy, but without the panels it would have been at least double that. It won't take long for the panels to pay for themselves.

 

[John Webb]

.....I am thinking perhaps the money would be better spent on insulation (foam on the outside of the walls as no cavity) as that stands to save more per year then solar panels, has a lot less to go wrong and probably last a lot longer. Downside could be flammability. That way using less energy in the first place rather than hoping to generate it cheaply.

Internal lining of the external walls with insulation covered with plasterboard is preferable, I understand - insulation not exposed to the weather, less needed and less fire risk. But you lose a few inches of internal space and may have to resite electrics such as sockets and wall lights.

 

[Shrewbly]

12 years in on my panels and no problems so far with either the panels or inverter. They do seem to lose a small percentage of generation per annum, probably half a per cent per year or so (they are probably now at around 94% of where they were when new), and I would expect the inverter will need to be replaced before too long. However improvements in inverters over the last decade mean that a replacement is likely to boost the generation from the panels back up again.

In my case the panels fully paid for themselves in 7 years.

 

[najaB]

Anyway I have often wondered about solar panels on the roof to power our home. How long will they work for I have wondered as I need to work out the total savings to balance against the cost. I have just seen this article and it stokes my fear that solar panels might not actually be worth it. Furthermore they seem to be an ecological mess as recycling them is difficult.

You should get at least 20 years out of a set of panels. The reason that there are so many panels being sent to recycling isn't generally because they've failed, but rather because solar farm owners upgrade their panels to get more power out of the same area. As others have pointed out, even at that 20 year point you'll probably be getting about 80% of the original rate power.

 

[cb a1]

I follow this guy on Mastodon - https://mastodon.scot/@Edent@mastodon.social/110469279398343952 and his blog - https://shkspr.mobi/blog/2023/08/solar-battery-statistics-day-one/

He posts lots and lots of statistics and thoughts about his solar panels and the battery system he's got.

 

[Ostrich]

I've had solar panels for about a year. Forget battery storage, that's expensive with a lifespan of about 10 years. My outlay was just over £7000 for a 3.6kW system. That includes an Eddi device to divert excess to the hot water tank. This time of year I'm generally exporting back to the grid after about 11am, with a completely heated up water tank.

== Doublepost prevention - post automatically merged: 6 Aug 2023 ==

I've had solar panels for about a year. Forget battery storage, that's expensive with a lifespan of about 10 years. My outlay was just over £7000 for a 3.6kW system. That includes an Eddi device to divert excess to the hot water tank. This time of year I'm generally exporting back to the grid after about 11am, with a completely heated up water tank.

My total energy bill last month was minus £56. Yes really I was paid 56 quid by my provider. Taking in to account my total consumption I am saving about £300 a month. Obviously during the winter that reduces, last year January I paid about £80 for energy, but without the panels it would have been at least double that. It won't take long for the panels to pay for themselves.

Very similar experience. Our 3.6kv array cost just over £6k a year ago; we didn't opt for battery storage as that would have doubled the cost (and an electric car isn't on our agenda at the moment), but we did get the gizmo that diverts excess electricity generated to heat the hot water tank first before exporting to the grid, and that seems to work very well. I reckoned that over last winter, we were saving around 40% on our monthly electricity bills, and gas consumption also reduced thanks to the gizmo.

 

[najaB]

we didn't opt for battery storage as that would have doubled the cost (and an electric car isn't on our agenda at the moment), but we did get the gizmo that diverts excess electricity generated to heat the hot water tank first before exporting to the grid, and that seems to work very well

You did go for battery storage, just a thermal rather than chemical battery.

 

[Peter Sarf]

Internal lining of the external walls with insulation covered with plasterboard is preferable, I understand - insulation not exposed to the weather, less needed and less fire risk. But you lose a few inches of internal space and may have to resite electrics such as sockets and wall lights.

Internal insulation I have pondered. Things in the way are the inevitable radiator under each window. One room has a door right in the corner against an outside wall - so perhaps I can manage an inch and no skirting near the door unless I hack off the plaster. Is it worth removing the plaster as I assume you gain a bit more good insulation. The bricks in our house seem to be very dense - cold to the touch so something on the inside might be pleasant.

You should get at least 20 years out of a set of panels. The reason that there are so many panels being sent to recycling isn't generally because they've failed, but rather because solar farm owners upgrade their panels to get more power out of the same area. As others have pointed out, even at that 20 year point you'll probably be getting about 80% of the original rate power.

You make me think - I wonder how much would second hand solar panels from a solar farm be ?. Or is too much of the cost involved in installing them ?.

 

[westv]

I get the impression that solar panels will save money for future residents of a house rather than the resident who instals it.

 

[najaB]

You make me think - I wonder how much would second hand solar panels from a solar farm be ?. Or is too much of the cost involved in installing them ?.

I don't know about UK suppliers, but there are a bunch of vendors in the US who sell second-hand panels. Typically at less than 50% the cost of new.

 

[Gloster]

Something that I read at least a decade ago that put me off getting panels at the time was that the contract with your supplier might cause difficulties when you sell your house. I can’t remember the details and it may have been sorted out since.

 

[najaB]

Something that I read at least a decade ago that put me off getting panels at the time was that the contract with your supplier might cause difficulties when you sell your house. I can’t remember the details and it may have been sorted out since.

The main issue there is that some suppliers don't actually sell you the panels, but rather lease them to you. Which turns off potential buyers since the lease comes with the house. If you have bought everything outright (either cash or with a normal bank loan) things are a lot simpler if/when you decide to sell up.

 

[Giugiaro]

In most of UK, solar power is insufficient to keep batteries recharged throughout the year - the daylight intensity is insufficient to recharge batteries on days like today (5 August), and too short during winter. You need to take batteries out of the device occasionally, and recharge them using a decent reliable battery charger (e.g. one that can distinguish between Lithium-Metal Hydride and other battery types).

I would assume such a setup would still be connected to the grid. Wouldn't the battery work as an energy bank for the grid?
The battery could be charged from the grid in low-demand hours and provide energy during peak hours.

At least, that's the setup I'm planning to install in my garage.
Since the garage sits in an agricultural field 300m from our home, it's more useful as a micro-generator and energy bank for the grid than as a self-sufficiency setup that will dump excess energy to ground, or potentially overcharge the battery.

 

[najaB]

I would assume such a setup would still be connected to the grid. Wouldn't the battery work as an energy bank for the grid?
The battery could be charged from the grid in low-demand hours and provide energy during peak hours.

Most higher-quality grid connected inverter/chargers allow you to do just this. I set up a small Victron system for my parents and it does have the ability to do scheduled charging. It's also possible to script actions via Node Red so that you could do things like trigger charging when energy prices are at their lowest if you're on a fully-flexible energy tariff. There are some available in the UK where prices actually occasionally go negative when there's excess wind energy available, meaning that the energy company will actually pay you to take power off their hands and then you can sell it back to them when demand is high.

I haven't actually configured this for them since there aren't any time-of-use tariffs available to them and they also don't export any energy.

Since the garage sits in an agricultural field 300m from our home, it's more useful as a micro-generator and energy bank for the grid than as a self-sufficiency setup that will dump excess energy to ground, or potentially overcharge the battery.

Just as an aside, you wouldn't be sending excess power to ground. Unlike wind, solar will only produce power when there is somewhere for it it go, if the battery isn't accepting any charge there will be a potential difference across the modules but no current flowing.

 

[AM9]

I get the impression that solar panels will save money for future residents of a house rather than the resident who instals it.

No, solar panels enhance the sale value and attractiveness of the house, (assuming that the house owner actually - owns the installation). Also the payback time of an installation is getting shorter with falling installation cost and rising energy prices, and that excludes the minimal export income.

 

[westv]

No, solar panels enhance the sale value and attractiveness of the house, (assuming that the house owner actually - owns the installation). Also the payback time of an installation is getting shorter with falling installation cost and rising energy prices, and that excludes the minimal export income.

So how long, on average, would it take to start running at a profit on the installation?

 

[Noddy]

I have often wondered about solar panels. I have over the years bought various solar powered devices and within a few years or less I have found they no longer work. My latest - an ultrasonic animal repeller has stopped working within 12 months. It can be charged from an external supply but no joy so maybe not the solar panel but the battery.

Anyway I have often wondered about solar panels on the roof to power our home. How long will they work for I have wondered as I need to work out the total savings to balance against the cost. I have just seen this article and it stokes my fear that solar panels might not actually be worth it. Furthermore they seem to be an ecological mess as recycling them is difficult.

Here is the link to the article, its a bit badly written so leads me to think it is open to interpretation. It got a bit repetetive towards the end so I might have missed something.

I was wondering what other people might already know ?.

MODS - I hope I am OK linking this ?.

Don’t believe everything you read. Here is a YouTube video from over 10 years ago (and processes have improved since then) explaining how they are recycled. While there is some complexity removing some of the components PV units are mostly glass and aluminium which as everyone knows are extremely easy to recycle. It’s a real shame that some (largely those on the right I’m afraid) love to promote myths.

So how long, on average, would it take to start running at a profit on the installation?

There are so many variables depending on location, roof angle and pitch, type and number of panels, shading, electricity usage, that that is like asking how long is a piece of string. If you enter your details on a calculator such as the one below you can get an estimate that is actually fairly accurate to your situation.

How much could you save with solar panels? | Solar Panel Calculator

pvfitcalculator.energysavingtrust.org.uk

 

[adc82140]

If energy prices stay where they are, mine will break even at about the three year mark.

As I write, it's cloudy but bright, 2.4kW is being generated, of which I'm consuming 100w, and exporting 2.3kW. The hot water tank is up to temperature. According to my smart meter data, I've used no gas for three months.

 

[najaB]

we didn't opt for battery storage as that would have doubled the cost (and an electric car isn't on our agenda at the moment)

One other thing to consider around battery storage is that most grid-tied system won't generate any power if the mains goes out, whereas even a small amount of battery storage will allow the system to continue operating during a daytime outage.

 

[AM9]

So how long, on average, would it take to start running at a profit on the installation?

My installation (12 x 345W panels, total gross power 4140W) feeding an SMA Sunny Boy 3.5 inverter, ac export limited to 3660W (DNO limits single phase unmanaged exports to 16A), Solar Boost+ controller for hot water storage cylinder, fully installed for under £5600. That was in Deember 2021. The original estimated payback period was about 10-13 years, however the actual is likely to be far less owing to:

Energy prices have risen above that allowed for in the original estimate​

By rescheduling certain high energy usage, i.e. dishwashing, clothes washing, tumble drying and clothes airing, the saving in electricity consumption has dropped from about 4MW/year to 2.5MW/year​

A moderate reduction of gas consumption by opportunistic use of electrically heated water from the Solar Boost​

the estimated payback period is probably now around 5-7 years.​

There is also in our case a previously unexpected benefit, - the house has a low pitched concrete tiled roof, which faces NE/SW. On even moderately hot days, the sun heated the roof up so much that the bedrooms were hotter at 22:00 than they were at 17:00, owing to the heat in the tiles radiating into the upper floor rooms, often making sleeping diffcult. The panels are mounted 100-150mm proud of the roof on a framework which ensures a ventilated space over most of the roof, thus keeping the rooms cooler without needing additional ventiulation inside the house and no perceptible impact in the winter.
Your question refers to profit, - note: exporting to grid doesn't really make much difference to us at £0.04 per KWh, but the reduced demand from the grid at £0.32 per KWh certainly does!

 

[adc82140]

That's not a great rate for export. I'm getting £0.15 per KWh from Octopus. Are you in a position to renegotiate with your supplier?

 

[Giugiaro]

Unlike wind, solar will only produce power when there is somewhere for it it go, if the battery isn't accepting any charge there will be a potential difference across the modules but no current flowing.

That's interesting. Thank you for pointing that out

 

[AM9]

That's not a great rate for export. I'm getting £0.15 per KWh from Octopus. Are you in a position to renegotiate with your supplier?

Not really, but I make every attempt to leave the minimum of energy for export so even if it was in double figures, it wouldn't make much difference to the overall savings. The way that the industry prices on the SEG (solar export gaurantee) is based on industry basic buy-in rates, i.e a feed when it isn't necessarily needed. I export to OVO, whereas my supply is from EON Next, so OVO don't have any extra business from me. There seem to be two ways to get a higher income per KWh exported:
1) export to the same energy supplier that fitted the system, - those suppliers would have priced the installation 25-30% higher that the independant contractor that I used
2) export is included as part of a supply package, trouble there is that most/all at the time were based on either battery storage or an functional EV smart charger.
I decided that it would take a few years of export to recover the additional cost of the system in 1) above, and I don't currenly qualifyfor the tariffs available for 2) above.
Last year I managed about £100 export income, even if it was £300, it wouldnt make it that much better, especially as i am likely either to get a battery fitted or an EV+smart charger that allows VtoP and VtoG in the near future. Then, export would be negligible anyway and the availability of demand driven rates would be the bigger benefit.

VtoP - Vehicle to Premises
VtoG - Vehicle to Grid

 

[rangersac]

No experience of solar panels in the UK, however I have had multiple houses in Australia with panels. My current house has the oldest installation, a 15 year old 2.5kW system that still is performing as designed.

Very similar experience. Our 3.6kv array cost just over £6k a year ago; we didn't opt for battery storage as that would have doubled the cost

I do find the price of solar systems in the UK bafflingly expensive. We installed a second 5kW system to supplement the aforementioned 2.5kW system a few years ago, and even with high quality panels and an inverter the total cost was around the £4.5K mark. These days for £6K you could easily get a 15kW system

 

[najaB]

I do find the price of solar systems in the UK bafflingly expensive. We installed a second 5kW system to supplement the aforementioned 2.5kW system a few years ago, and even with high quality panels and an inverter the total cost was around the £4.5K mark. These days for £6K you could easily get a 15kW system

It seems that most of the cost is in labour, and getting scaffolding to work on a roof isn't cheap (can add the better part of £1K to the total cost by itself).