Solar Panels UK - is it worth it?

[phil4]

Before yesterday's bump it was hard to get anyone to actually install solar, all too busy. Today I think they're actively turning people away now. It really needs more people fitting, lets hope as this has a 5 year run, it does that. I'm with PITA though, I can just see the installers soaking up the savings.

 

[GlynG]

The Solar industry were very busy for years and lots of new companies sprung up, however many soon packed up again due to the buy cheap stuff and maximise profits - the industry attracted the fly boys - many installers were earning in excess of £100K per annum, however their final swansong was just prior to the ending of the FIT payments - everybody that was thinking of solar jumped in - though having storage batteries back in 2018 was still unusual.
Then the industry died after March 2019 - the demand slumped, firms went bust and many installers were made redundant, this continued until energy prices started to rise and the latest price rises have seen unprecedented demand for Solar and batteries. This will undoubtedly attract the Fly Boys back so people should research products available and pretty much know what they want down to the panel type, the output, the efficiency and the manufacturer, plus the type of inverters available and battery systems - those that don't do the research will probably get fleeced into buying older technology and lower quality hardware. One final comment - spend some time investigating the companies offering Solar, many have years of experience and attract good reviews though that doesn't entirely protect you from poor customer service - you need to be assured the guarantees will be honoured and the company still trading in a few years time. The company i used was engaged after many weeks doing research - they had a good name but answering the phone when you call them is dodgy at best and current reviews suggest they have not improved. The electrician during the initial installation got a few things wrong and i saved nothing, It took their trouble-shooter to visit and put things right - and he did a superb job. My system performs brilliantly and I'm so pleased with it. (The electrician was let go by the company for those interested) The company EEC at Stockport.

 

[The_Cable_Guy]

my concern is longevity/degredation of the parts.

I.e the payback vs reward/renew.

Are the panels going to be as effiecient in 5 years time as the are new, same as the batteries.

My simply man maths: Erray and battery costs minimum 10-15k

Energy bill say 2k per year, you save an optimistic 80-90% of that due to switch to solar. Saving you a very optimistic £1800 per year (dont think this is real world is realistic)

£15000 - 1800PA = 8yrs+ for repayment

possibly not factorting in damage/servining if any is needed? im a complete noob on this.

Several things to think about,

1: are you going to be in this property in 10years time,
2: will the powerwall / battery erray still be 100% functional & effiecient in that timeframe.

not playing devils advocate as im sure everyone else things these things too, bit like when the window salesman tell you his more expensive windows will save you 20% more off your energy bills, yet the cost is 5k higher, and with simple man calcs the difference will never be repaid before they need replacing again in another 15-20 years.

 

[Avendit]

The panels should come with parts guarantee and planned degrigation rates that the manufacturer will honour a fair bit out.

Batteries tend to be warranty'd to a certain capacity after a given number of years and or cycles. 10k cycles gives you approx 10 years of 2 cycles a day, and anything after that is a win. Even then the battery is t useless, just degraded.

How long you will be there is obviously a different question, but as long as you don't have current plans to move, they should count towards the value of the property and they do impact the EPC rating, which will also add to the value.

Look back the thread to (I think) the mid 20 pages - a few example spreadsheets for working all this out are included. Bu basically, your estimate is pretty much bang on and adding more detail just refines a bit and gives greater confidence. Payoff is between 4 and 8 years depending on the cost of power in the mean time, bigger arrays and adding batteries increases the speed of payoff, but you start further in debt so they all turn positive at roughly the same time. After that it's just how much you are in 'proffit'. Of course you aren't really in profit, just less dept to the power company.

Over 25 year I expect to give them £60k+ less money than I would otherwise tho, so it makes complete financial sense, and the potential for grid independence and being green is very appealing.

 

[WannabeOwner]

Are the panels going to be as efficient in 5 years time as the are new

Mine are guaranteed to be no less than 90% efficient after 25 years.

possibly not factoring in ...

Electricity price increases? I didn't anticipate price of electricity doubling "overnight". I didn't put mine on the roof for payback, per se, but the recent price increase has taken care of that.

For me the maths that works is when you have, say, £10K of savings. You can stuff that in the bank - no doubt that will do well with inflation at 7% - but even so, it might not keep pace with inflation, and it was pants when interested rates were close to 0%. You'll have to pay tax on that savings interest "income" too

Or you could buy £10K of solar panels, and reduce your electricity bill by £500 a year. That's a 20 year payback (which, as you rightly say, is "pants" in that context) ... but its 5% return on your money. Tax free. And index linked, in the sense that every time the price of electricity goes up your "income" increases.

Only downside is that with £10K in the bank you can take it out again. Can't do that with Solar Panels ... but likely you would get some of that back if you sold your house.

Meantime the early adopters also got FiT payments ... and (pitful) export rebates too.

 

[The_Cable_Guy]

completely agree with what both you guys are saying,,, interesting about the 90% efficiency, thats great after that time (if the company is still here ) haha

I would imagine with energy prices rising and everything else rising so will the cost of solar as the demand increase, just simple supply and demand.

 

[WannabeOwner]

if the company is still here

Panasonic.

 

[Tony Hoyle]

My 2.5kw is peaking at 2.2kw after 8 years. So.. about 12%? 1.5% a year. I'm on a 20 year payoff provided they don't fail completely before then.

From what I can tell of the warranty there are no guarantees of performance, just 'parts and labour' - but the company went bust years ago, so it's probably just toilet paper at this point. Thinking of getting the lot ripped out and more modern panels put in.. although I'd lose FIT..

 

[PITA]

I wonder how many house fires will result from all this... shoddy products, shoddy installations, no paperwork and no DNO approvals...

Cash mate...

 

[init6]

Over 25 year I expect to give them £60k+ less money than I would otherwise tho,

You really need to switch off some servers

 

[Avendit]

completely agree with what both you guys are saying,,, interesting about the 90% efficiency, thats great after that time (if the company is still here ) haha

Panels are supremely simple. They are made of 'stuff' (the chemistry is increasingly exciting) that when exposed to light makes electricity. No moving parts, no wear and tear. Just really basic physics.

The electronics around the panels of stuff does wear, and you will probably need a new inverter around year 10, but that's it. Keep the panels clear and don't throw rocks at them.

 

[WannabeOwner]

From what I can tell of the warranty there are no guarantees of performance, just 'parts and labour'

This is Panasonic warranty (lifted off their website, my own personal warranty might say "On your bike", I haven't dug it out of my files to check ). Looks like they expect some drop off in first year, OR that is for manufacturing tolerance perhaps.

Limited Power Output Warranty. Panasonic USA warrants the power output will be no less than 97% of the designated Maximum Power (Pmax) stated in the Product data sheet for the first year from date of purchase of the Product by the Owner and the power output degradation will be no more than 0.26% per year for the following 24 years, so that, at the end of the 25th year, the power output will be at least 90.76% of Pmax. The power output values under this Limited Power Output Warranty shall be those measured under Panasonic USA’s Standard Test Conditions (STC) as follows: (a) Irradiance 1000 W/m2, (b) Cell Temperature of 25ºC, and (c) Air Mass of 1.5g.

 

[Tony Hoyle]

I've no idea who made my panels.. probably some unknown chinese outfit..

 

[Mrklaw]

If you’re doing 2500kwh a year that’s a FIT of nearly £500 depending what rate you locked in but they were ok back then still. Wouldn’t replace them in a hurry just for more kw - but I would look at a battery to soak them spare PV kw up and shift off peak

 

[Tony Hoyle]

My max annual fit is about £350.

Battery makes no sense at that level of output as it would be empty almost all the time. Great during summer but the panels don't produce enough to make it worth it - for example today is sunny spring day - I exported 6.2Kwh and used 9.7Kwh from the grid, so assuming 100% of the export being put in a battery and reducing grid usage, the battery would still already be empty.. I'd have saved some, but not enough to make it worthwhile. On a cloudy day it wouldn't charge the battery at all.

 

[Mrklaw]

I have a similar size and during the solar hours don’t use much - maybe 40% of what’s generated. So there is solar I can use for later in the day but I do realise I’d need to use off peak also.

So I’m liking at it more as an off peak shifting solution with a bonus of some PV bringing the cost/kWh down a little more

 

[roadcred]

A couple of weeks ago I asked my installer to quote me for a second Powerwall. He said in his experience our DNO is likely to refuse permission.
I then asked him what the situation would be with the DNO if I got a 3 phase supply into the house. He responded that it would be approved but that we would then need 3 powerwalls at the property, one for each phase? I think that is wrong, does anyone here have experience of such an eventuality?

 

[Mrklaw]

You can set the power walls to avoid discharging to the grid can’t you? If you were willing to do that then shouldn’t the DNO be ok?

 

[PITA]

A couple of weeks ago I asked my installer to quote me for a second Powerwall. He said in his experience our DNO is likely to refuse permission.
I then asked him what the situation would be with the DNO if I got a 3 phase supply into the house. He responded that it would be approved but that we would then need 3 powerwalls at the property, one for each phase? I think that is wrong, does anyone here have experience of such an eventuality?

Yeah, I think they're wrong... this is what we did below... so it can be done.

Our house used to be on a standard Single Phase supply, going into a Single phase meter. Through to a Single Phase Consumer Unit.

Our two Powerwalls powered the house on this Single Phase, and backs it all up through the Tesla Gateway 2. So we had no problems with two Powerwalls on a Single phase supply.

Now we have a replacement 3 Phase supply, going into a 3 Phase meter, and then into a 3 Phase distribution board.

But... we've kept the house on Single Phase, and the Single Phase Consumer Unit. No need to change because there's no high loading inside the house.

However, we now have access to this new 3 Phase distribution board and can attach things to that... like a 3 Phase 22kW Ev Charger as an example.

No idea why you would need 3 Powerwalls on each Phase... sounds completely over the top? ... if your house isn't already loaded with 3 Phase appliances and needs that capacity

Our two Powerwalls continue to provide the house with full backup on Single Phase... and we charge the car on 3 Phase.

 

[Dilly]

A couple of weeks ago I asked my installer to quote me for a second Powerwall. He said in his experience our DNO is likely to refuse permission.
I then asked him what the situation would be with the DNO if I got a 3 phase supply into the house. He responded that it would be approved but that we would then need 3 powerwalls at the property, one for each phase? I think that is wrong, does anyone here have experience of such an eventuality?

Sounds odd to me. Our local grid has been oversubscribed for generation for years. My DNO allowed a second Powerwall and extra panels provided they couldn’t export. I can’t see why they’d block it.