Author Topic: Solar tile panels  (Read 8370 times)

jane

  • Mad pie-hating female
Solar tile panels
« on: October 23, 2010, 05:31:31 pm »
It looks like we are going to need a new roof soon.  I've always been interested in the idea of solar power and as our roof is south facing on one side I have been trying to find out if it would be a good idea to install solar tiles but trawling through the huge amount of information out there is leaving me even more confused than when I started- any recommendations/advice would be much appreciated.

Re: Solar tile panels
« Reply #1 on: October 23, 2010, 05:44:14 pm »
Something else to consider would be solar water heating.  I'll post a link if I can track one down.

Re: Solar tile panels
« Reply #2 on: October 23, 2010, 05:47:06 pm »
Here's the CAT link.

tonycollinet

  • No Longer a western province of Númenor
Re: Solar tile panels
« Reply #3 on: October 23, 2010, 07:58:54 pm »
I think from a payback point of view, solar water is much better than solar electricity.

hellymedic

  • Just do it!
Re: Solar tile panels
« Reply #4 on: October 23, 2010, 08:22:22 pm »
It would not be for me; we don't use much hot water.

Euan Uzami

Re: Solar tile panels
« Reply #5 on: October 23, 2010, 08:36:19 pm »
a bloke at work has recently had them installed from what he says  the amount of schemes you can opt for is mind boggling, in choice and complexity, most involving various complex equations between purchase price, amount of electricity they produce, amount of electricity they are expected to produce, amount of electricity you use, whether you opt for water heating ones or photo-voltaic cells, whether you choose to feed the energy back into the grid or just use it, offsetting the interest on the purchase price, tax, god knows what else. Probably also takes into account which way the wind's blowing, what colour trousers the london to newcastle train driver is wearing and the planck constant.  ::-) ;) A mine field definitely. Good luck  :thumbsup:

Euan Uzami

Re: Solar tile panels
« Reply #6 on: October 23, 2010, 08:38:59 pm »
It would not be for me; we don't use much hot water.

that's what my colleague thought before he discovered the photo-voltaic variety. Not all solar panels are the same, not all providers are the same, and not all schemes are the same.  :) (I don't understand it, particularly, I hasten to add - I just know it's not a simple business!)

Re: Solar tile panels
« Reply #7 on: October 24, 2010, 08:41:32 am »
PV pays you a guaranteed rate of return over 25 years if you can afford the £20-30,000 upfront cost.  Actually, it pays back even if you need to take out a mortgage to buy the panels.  The only reason we haven't done it (we have an ideal roof for it, being south-facing and early-1980s with a gentle pitch) is that I don't fancy any more debt these days.

Other people will install them on your roof for nothing, but they get the returns*; you just get to use the free electricity when it's available.


*which are wholly disconnected from the amount of electricity produced; it's a very silly giveaway which is bound to be closed off by the government any time now
Never tell me the odds.

Re: Solar tile panels
« Reply #8 on: October 24, 2010, 02:39:18 pm »
Something else to consider would be solar water heating.  I'll post a link if I can track one down.

But then to make the most you need washing machine and dishwasher that are "hot fill", and many/most aren't these days,
We are making a New World (Paul Nash, 1918)

Wowbagger

  • Dez's butler
    • Musings of a Gentleman Cyclist
Re: Solar tile panels
« Reply #9 on: October 24, 2010, 02:41:53 pm »
Something else to consider would be solar water heating.  I'll post a link if I can track one down.

But then to make the most you need washing machine and dishwasher that are "hot fill", and many/most aren't these days,

They are if you connect them to the hot pipe!
Oh, Bach without any doubt. Bach every time for me.

Re: Solar tile panels
« Reply #10 on: October 24, 2010, 09:20:23 pm »
1. Are you thinking about installing solar PV roof tiles as a replacement roof covering?  If so, then you need to consider
(a) that this would probably work out more expensive than just replacing the roof and then mounting ordinary solar PV panels on top, and
(b) that any solar PV tiles you do select - if you go down that route - must be MCS accredited otherwise you won't be eligibile for the Feed-in Tariff.

2. The Government's recent Spending Review confirmed that they will be introducing a Renewable Heat Incentive (RHI) - a sort of Feed-in Tariff for heat - during 2011-12 (target date is April 2011).  Any solar hot water schemes that are MCS accredited installations that are done now WILL be eligibile for the RHI when it is introduced.  However, whilst the RHI tariff payments have been out at Consultation, the final shape of the scheme has not yet been announced, but it will be a useful incentive nonetheless.

Typical payback on conventional "on-roof" (mounted on top) solar PV systems now is 8 - 12 years for a domestic installation.  The Feed-in Tariff pays 41.3p for every kilowatt hour of electricity you generate irrespective of whether you use it on site or not.  For every kWh that you export (i.e. don't use yourself) you get paid an additional 3p.  A typical 3 bed semi-detached house with a reasonably southish facing roof would fit something like a 2 kW peak output sized PV array, and this would generate about 50% of your annual electricity needs.

I installed a 3.5kW peak output array on a WSW facing roof here at Quisling Towers (i.e. sub-optimal but some margin) back in May and have nearly generated 2000 kWh.  I reckon I'll do about 2500 kWh+ over a 12 month period.  The average UK home uses about 4500 kWh of electricity per year.  Fortunately I use less so I reckon I'll be about net zero usage across a 12 month period.

PV is pricey, but has come down a lot in the last 12 months.  Ensure you get quotes from MCS accredited installers, and then haggle!  Domestic sales techniques are akin to double glazing and conservatories so you should be able to squeeze a 4 figure sum off the original price you get quoted.

Any PV installation should have an Ofgem registered generation meter installed to record generation for the purposes of claiming the Feed-in Tariff.  The FiT can be claimed from your electricty supplier (the big 6 are all mandated to provide FiT payments, but smaller suppliers with < 50000 customers don't have to).

Quisling

jane

  • Mad pie-hating female
Re: Solar tile panels
« Reply #11 on: October 25, 2010, 07:44:20 am »
That was extremely useful- still mind boggled but slightly less so and am now able to at least develop a line of enquiry- thanks folks.

border-rider

Re: Solar tile panels
« Reply #12 on: October 28, 2010, 08:53:35 pm »
I just got a rough quote for 16k and about a decade payback for 4 kW of PV

OK, but that doesn't seem to make economic sense to me - unless you're in it for 20 years, guaranteed.

border-rider

Re: Solar tile panels
« Reply #13 on: October 28, 2010, 09:03:58 pm »
but they get the returns*; you just get to use the free electricity when it's available.


*which are wholly disconnected from the amount of electricity produced; it's a very silly giveaway which is bound to be closed off by the government any time now

This is bizarre

You get 100% of the payment for what you produce, even if you use it all yourself.

Re: Solar tile panels
« Reply #14 on: October 29, 2010, 01:23:16 pm »
but they get the returns*; you just get to use the free electricity when it's available.


*which are wholly disconnected from the amount of electricity produced; it's a very silly giveaway which is bound to be closed off by the government any time now

This is bizarre

You get 100% of the payment for what you produce, even if you use it all yourself.

£16k for 4kWp sounds like a typical first quote price.

The Feed-in Tariff is not really a "Feed-in" to the grid tariff, it's an incentive to increase the uptake of renewables and provides a decent return on your investment, rather than a decent return for feeding power back to the grid.

You get three income streams from installing domestic PV.  In order for value they are:
1. the FIT generation payment (varies, but is 41.3p for domestic retrofit < 4kWpeak)
2. the savings you make by offsetting against reduced import electricity from the grid
3. the FIT export payment (3p/kWh for every kWh you export).  Export is currently deemed at 50% of total generation, but once smart metering is rolled out in the next few years the export payment will be based on actual measured export.

The tendency amongst domestic consumers is to think in terms of simple payback calculations - e.g. it'll take about 10 years for me to get my money back.  However, if you think in terms of investment income then it starts to make more sense as the FIT was designed to deliver 5-8% return on investment.  Factor in that this payment is INDEX LINKED TO RPI AND TAX FREE then in real terms it's worth perhaps 9% or more.  You won't get that of an ISA any time soon.

The average home occupancy before moving is about 12 years.  Estate agents haven't yet really figured out how to value a home with PV on it.  The FIT is transferrable to the new owner, so when you sell up you're selling a property with an ongoing income stream and a valuable asset strapped to the roof.

If the PV does take 10 years to pay back, there's still another 15 years of FIT income (it pays for 25 years on PV), and after that you still get the savings from the reduced import.

Notes of caution:
1. PV output degrades over time, but MCS accredited panels will generally give at least 80% of "as new" performance after 20 years.
2. Mean time to first failure of the inverters is likely to be much shorter - about 10 years or so.  Accordingly, you'd need to factor in £500 - £1000 to replace the inverter half way through the FIT period.

To put that into context, my (sub optimally located) 3.5kW peak output (which only gets to about 2.85kW because it faces WSW) earned me £525 in FIT income from mid May - mid August this year.

Hope this helps.

Q

border-rider

Re: Solar tile panels
« Reply #15 on: October 29, 2010, 06:45:13 pm »
but they get the returns*; you just get to use the free electricity when it's available.


*which are wholly disconnected from the amount of electricity produced; it's a very silly giveaway which is bound to be closed off by the government any time now

This is bizarre

You get 100% of the payment for what you produce, even if you use it all yourself.

£16k for 4kWp sounds like a typical first quote price.

The Feed-in Tariff is not really a "Feed-in" to the grid tariff, it's an incentive to increase the uptake of renewables and provides a decent return on your investment, rather than a decent return for feeding power back to the grid.


The tendency amongst domestic consumers is to think in terms of simple payback calculations - e.g. it'll take about 10 years for me to get my money back.  However, if you think in terms of investment income then it starts to make more sense as the FIT was designed to deliver 5-8% return on investment.  Factor in that this payment is INDEX LINKED TO RPI AND TAX FREE then in real terms it's worth perhaps 9% or more.  You won't get that of an ISA any time soon.

Except...you don't get the initial capital back*, and it doesn't compound


*value of installation at end of useful life = -ve several k£

Re: Solar tile panels
« Reply #16 on: October 29, 2010, 11:20:46 pm »
MV - I agree that having someone else install them "for free" for you is the option of last resort.  The returns by doing it yourself are significantly better.  Moreover, at a domestic scale it's only worth installing them for free if you can get optimum sites, i.e. 3.5kW approx, south facing, pitched roof, no shading etc, so the average punter isn't going to get it installed for free,

Q

border-rider

Re: Solar tile panels
« Reply #17 on: February 04, 2011, 02:32:20 pm »
Thread resurrection triggered by a piece on C4 news about this last night

We have an expanse of Sth-facing roof, ideal for solar PV.  But I can't get my head around the economics (I'm reasonably unconvinced that there's an environmental case)

The figures they were quoting last night - and these tally with my own research - is that about 4 kW installed will cost about 13k and will get you about a 10% return per annum (all +/- a bit of course) when you include your own usage, being paid to expert when you aren't etc, and that the tariff is maintained (as it wasn't in German).  So best-case, I think.

Now, that's a decent return on your money, but of course you lose the initial investment, so it's not like a deposit account.  On that basis it takes a decade to get your money back, and then say you have a clear decade of actual income before the panels die; 20 years seems about right though you might get more with luck.  So after 20 years you've doubled your money.

That doesn't seem like a great investment to me - you can get 4% easily from a bond at the moment and over 10 years that would get you 50% plus your initial sum, and over 20 years it'd be 2.7 times the initial investment.

Now, of course, it may be that tariffs rise hugely or that electricity becomes so expensive as to be a luxury -  and then all bets are off.   But taking it as an investment decision, all else being equal, it doesn't seem to me to stack up.

What am I missing ? I really want to make this work, but I can't.

MikeFromLFE

  • Previously known as Millimole
Re: Solar tile panels
« Reply #18 on: February 04, 2011, 03:59:08 pm »
I was tempted to explore the government subsidised schemes - but two things have stopped me dead in my tracks.
The first is similar to Rogerzilla's point about taking on more debt - at my age (55) even with no intention of moving I don't fancy fitting something to my house that will have a 20+ year lifespan, and the accompanying debt issue - particulalry as our house roof is more south-east than south facing, so unlikely to get the full grant. Secondly, I've heard from a couple of sources (the most recent being BBC Radio 4's Money Programme) that it is, under current arrangments next-to impossible to get a mortgage on a house whose roof is leased to a Solar Panel Company - this effectively makes your house unsaleable with a roof fitted with panels that you have not paid for fully yourself.
I've not ruled out the garage roof though!
Too many angry people - breathe & relax.

LEE

Re: Solar tile panels
« Reply #19 on: February 04, 2011, 04:01:46 pm »
worth perhaps 9% or more.  You won't get that of an ISA any time soon.


Depends which ISA you choose.  Plenty will outperform 9%

Thor

  • Super-sonnicus idioticus
Re: Solar tile panels
« Reply #20 on: February 04, 2011, 04:19:13 pm »
worth perhaps 9% or more.  You won't get that of an ISA any time soon.


Depends which ISA you choose.  Plenty will outperform 9%

An ISA is just a tax wrapper - it's the underlying investment which performs - or not.  I'd like to know how to get a reasonably safe 9% return though.
It was a day like any other in Ireland, only it wasn't raining

urban_biker

  • " . . .we all ended up here and like lads in the back of a Nova we sort of egged each other on...."
  • Known in the real world as Dave
Re: Solar tile panels
« Reply #21 on: February 04, 2011, 04:28:13 pm »

An ISA is just a tax wrapper - it's the underlying investment which performs - or not.  I'd like to know how to get a reasonably safe 9% return though.

I can get you a 100% return - just bet on black. Ahh - I see you said safe  ;D
Owner of a languishing Langster

iakobski

Re: Solar tile panels
« Reply #22 on: February 04, 2011, 04:30:52 pm »
Quote
What am I missing ? I really want to make this work, but I can't.

Possibly two things:

1. you assumed the coupons from your bond are compounded, but the returns from the solar just added up rather than invested.

2. the returns from the solar are a mix of the feed-in tarriff - I assume this is fixed that's what the guarantee is for - plus what you save on not having to pay for electricity - this is not fixed. I reckon 5% price inflation on fuel is probably conservative unless there's some amazing technological breakthrough, but who knows?

So. Supposing your 1,300 return is made up of 300 cash for feed-in plus 1000 saving in fuel bills, with the latter increasing 5% annually, that gives you 39K cash over 20 years as opposed to 26K (double your money). To compare with the bond, if you took the coupon that would give you 10.4K cash plus your 13K investement back.

That's not a good comparison because with the bond the total figure is not spread evenly, you take the capital out at the end. So, suppose you compound the bond coupon and invest the electricity cash at 3%. After 20 years you have 27.4K from your bond against 48.5K from your solar panels.

Lots of arm-waving figures, and my sums may well be wrong, but if it doesn't work out you can heat your house with the warm glow of self-satisfaction at being non-fossil fueled.

nicknack

  • Hornblower
Re: Solar tile panels
« Reply #23 on: February 04, 2011, 04:33:44 pm »
but if it doesn't work out you can heat your house with the warm glow of self-satisfaction at being non-fossil fueled.

Apart from the fossil fuels used to make the solar panels of course.
There's no vibrations, but wait.

Wowbagger

  • Dez's butler
    • Musings of a Gentleman Cyclist
Re: Solar tile panels
« Reply #24 on: February 04, 2011, 04:37:44 pm »
but if it doesn't work out you can heat your house with the warm glow of self-satisfaction at being non-fossil fueled.

Apart from the fossil fuels used to make the solar panels of course.

And the fact that about 90% of the electricity they produce is when you don't need to use a lot of electricity.
Oh, Bach without any doubt. Bach every time for me.