Viewing 40 posts - 1 through 40 (of 47 total)
  • Photovoltaic solar cells- a no brainer?
  • TomB
    Full Member

    Hi all. We’ve got a virtually spot on south facing roof, and I’ve been investigating PV solar power, government guaranteed returns from selling to the grid etc. If the capital is not raised by getting into debt, and therefore having to pay interest, it seems a decent way of spending some money to reduce outgoings/earn a little over the medium term. Any horror stories? All input gratefully received from the encyclopaedic STW knowledge base. Sorry if it’s been done before….

    Cheers.

    avdave2
    Full Member

    Governments have been known to break promises in the past. You should also consider will you be able to keep them clean without too much difficulty. Also consider that the payback times shown compared to investing the money in the building society etc are based on current very low interest rates. Also as far as I can see they also don’t take into consideration the compound interest on your savings if they are elsewhere.
    These feed in tariffs will push energy prices up and the people who are the poorest who don’t own their own homes and who cannot fund the installation will be the ones who subsidise the relatively wealthy. They might start to get just a little pissed off with that and maybe one or two politicians will cotton on to that and see the removal of middle class subsidies as a vote winner.
    In short if you think the Government(s) will keep a promise for at least a decade, if you believe that interest rates will stay low for a decade and if you don’t give a dam whose subsidising you then yes it’s a no brainer.
    I’m in no way against installing pv but I don’t think you should rely on points 1 and 2.

    Trekster
    Full Member

    Does the efficiency of the panel not start to deteriorate over a period of time and therefore become less efficient?

    How do these panels fix to the roof and what long term effects does fitting them have?

    IME the design life of photovoltaic systems doesnt usually equal the payback period, so make sure you factor that in if you are running the calcs. A bit like the electric cars tested on topgear where the batteries only last a few years (3-4?) then cost £xk to replace.

    And as said above, dont think the feed in tarifs will exist forever.

    allthepies
    Free Member

    If you can spare the money then it’s a no-brainer. The tarrifs are guaranteed so baring alien invasion or the Labour party getting back into power then you’re sorted.

    lump
    Full Member

    The feed Ins will be replaced with the Green deal. And when it come out costs will be a lot cheap if not free. So if you want to get the best deal get on the feedins before this happens.

    mikey74
    Free Member

    IMO you would be better of fitting one of these Watt Box rather than eco bling such as photovoltaics

    big_n_daft
    Free Member

    If I had the cash I’d probably do it before the tariff dropped too much

    I agree with avdave2, but essentially it’s a good deal

    MrNutt
    Free Member

    PV can give reasonable returns but be careful when selecting both the installer and the panels, its like the wild west out there! if you would like a reputable company drop me a line and I can point you in the right direction.

    If you live in an area with a wind speed of +5 meters per second you would be better off investing in a 5kW Wind turbine as the RoI is better, again if you’d like more info contact me off forum, I’m not selling on here!

    wonnyj
    Free Member

    I’ve been doing lots of consultancy work on solar PV installations, mainly for social housing landlords. I think the majority of FIT supported PV installations will be going on social housing roofs so therefore reducing the electricity bills of some of the poorer people in society.

    Obviously it’s a good investment if you have got the cash and are not planning to move house.

    It will also reduce bills by approximately 1/3 for most homes depending on electricity usage patterns.

    Over a 25 year period you will need at least 1 inverter replacement. Most are warrantied for 10 years.

    Most decent panels are guaranteed to not drop more than 10% after 10 years, and 20% after 25 years. So you might as well call that 1% reduction in generation per year.

    They’re supposed to be self cleaning – there is no market for PV cleaners in Europe apparently (I’m not 100% convinced of this though).

    Don’t pay more than £3,200 per kW installed for a roof mounted system.

    Look for a contractor that’s been installing PV (and MCS registered ) for more than 5 minutes.

    Oh and be careful about how you place them on your roof. Any shading, even minor, can cut the output significantly as the panels are wired in series.

    Roof mounting shouldn’t be an issue with a reputable contractor.

    ps44
    Free Member

    “…therefore reducing the electricity bills of some of the poorer people in society…” which is being paid for by the other poorer people in society with inflated energy bills to cover the subsidy.
    I looked very hard this. I could afford to do it, have got a favourable location, but (a) don’t believe the subsidies will survive (as “copper-bottomed” as other political commitments) (b) don’t think I should be sponging off people less well off than me to get an investment return (c) am waiting for several more generations of technology before it really pays for itself (d) think the energy market is going to go haywire when the AGW bubble finally bursts.

    Nice sunny day for riding though 😀

    wrecker
    Free Member

    Indicative lifespans of PV panels are 25 years according to CIBSE guide M. Most manufacturers guarantee that their panels are at least 80% efficient at the end of their lives. Cleaning must be performed annually.
    Whats going to happen with the fed in tariffs? Nobody knows.
    Maybe others are subsiding the FITs, but I think you should be able to sleep soundly in the knowledge that you are producing energy without burning fossil fuels.

    TooTall
    Free Member

    If you live in an area with a wind speed of +5 meters per second you would be better off investing in a 5kW Wind turbine

    *cough*slightly misleading*cough*

    Trimix
    Free Member

    Dont forget the FIT is there as a way for the electricity companys to offsetting the carbon they produce. Its like a tax on them.

    We are getting one fitted and expect to make £1200-£1300 a year. Big south facing triple (as in long) garage roof.

    We dont use electricity in the day, apart from a fridge, and bugger all in the evening, so 99.9999% of the electricity feed in for us is profit.

    We have the dosh doing nothing in savings, but actually will use a zero % credit card to ease the payemnt even further.

    Really is a no brainer. In the future I would expect electricity companys to be under even more pressure to offset the carbon they produce.

    oliverd1981
    Free Member

    They’re supposed to be self cleaning – there is no market for PV cleaners in Europe apparently

    But they don’t have neighbours who still have a coal fire on the go 365.

    I have to say I’m dubious, the PV panels I’ve worked on ( smaller ones) tended to fail through water ingress, delamination etc. I can’t see rush manufactured large scale panels lasting 10 years. Also I’m in the grim north and my vitamin D deficiency is a pretty good indication of how much sunlight we get.

    How many of us have to club together to buy a STW offshore turbine?

    MrNutt
    Free Member

    TooTall, how do you figure that?

    T1000
    Free Member

    I’d be cautious about the durability of pv’s theres a lot of snakeoil salesmen…..
    Although the panels should in theory survive it’s the mounting hardware, terminations, fieldwiring and inverters and likely to require replacement before 25 yes + most warantees will not be worth the paper there written upon… Then there’s technological obselesence for for the control panel….

    TomB
    Full Member

    Thanks, food for thought. Does anyone have any idea if there is to be a big jump in efficiency/technology of the cells imminently? In lots of tech people always seem to be ‘holding off’ for the next new release- would that be the case for PV?

    Figured there would be a lot of cowboys jumping on the bandwagon, will make sure I do my research! Do the sellers/fitters get grants/hidden income other than from the customer?

    totalshell
    Full Member

    name one electrical appliance in your home that lasts for 25 years, name one metal item that is in an exposed position outside that requires no maintenance.

    allthepies
    Free Member

    name one electrical appliance in your home that lasts for 25 years

    My fusebox.

    name one metal item that is in an exposed position outside that requires no maintenance.

    My TV aerial.

    MrNutt
    Free Member

    heh heh, nicely done!

    T1000
    Free Member

    hmmm wylex fuseboard……. = doublepole switch + rewirable fuses ….. not much happening inside one of those…… + made in there millions compared to low volume product made with discrete components……. the world full of legacy systems and products where the components are either unavailable or rely on some very reasorceful people to provide backup

    tv ariel bit of galv scaffold pole nice and chunky of course it will last…..

    konabunny
    Free Member

    They might start to get just a little pissed off with that and maybe one or two politicians will cotton on to that and see the removal of middle class subsidies as a vote winner.

    Who is it that votes in the UK?

    which is being paid for by the other poorer people in society with inflated energy bills to cover the subsidy

    Meh – the proportion of UK power generation that’s going to be accounted for by rooftop generation (and therefore going to have to be cross-subsidised by non-generating consumers) is minute. For everyone one house that’s got a panel, there will be hundreds of flats, shops, offices, factories etc that will still be burning through huge amounts of electricity.

    TooTall
    Free Member

    Does anyone have any idea if there is to be a big jump in efficiency/technology of the cells imminently?

    Not that is affordable. 17 – 18% is about the best mono silicon and best bang for buck right now. There will probably be more lower efficiency products coming out that are cheaper to produce – so you put more out for the same effect, but cheaper overall.

    Mr Nutt – slightly misleading because you missed the word ‘average’ when talking about wind speed and ‘possibly’ when talking about a wind turbine being a better investment. The site survey for wind is a bit more detailed than it is for solar and takes more time and there are far more variables involved – so just saying a 5m/s wind makes a turbine better is a little misleading.

    MrNutt
    Free Member

    Renewable energy provision is essential, its getting cheaper by the day in many cases and that’s due to demand. The Feed in Tariffs are a very positive thing.

    Saying that people shouldn’t receive incentives to generate enough for their own usage and be rewarded for feeding power back into the grid, due to it damaging your choice to buy nonsustainably produced energy from a marketplace of different suppliers is akin to Reform Luddism!

    zippykona
    Full Member

    Surely we are missing the most important thing.
    The more people who have these the less power stations we will need.
    Power stations will soon be owned and run by the Russians.
    They held the Ukraine hostage. Anyone trust them more than our government?
    Power self sufficiency should be our number one concern.
    Nuclear power station , nuclear target. Can’t imagine Johnny Terrorist being bothered to blow up eveyone’s solar panels.

    donsimon
    Free Member


    More than one way to skin a cat, zippykona.
    Why all this talk of trying to produce more energy, surely the solution is to reduce our current consumption?

    TooTall
    Free Member

    Nuclear power station , nuclear target. Can’t imagine Johnny Terrorist being bothered to blow up eveyone’s solar panels.

    Given we have had nuclear power stations for quite some time and they have yet to be attacked, your arguement is flawed.

    Given that a nuclear power station is designed to contain a nuclear incident, you would need something like a nuclear device to breach the nuclear power station. So why waste that if you have it? Using such a device in a heavily populated area rather than on a nuclear power station (in a remote area) would be far more effective.

    don – both. Reduce and improve efficiency. Don’t forget that as and when oil runs out, the electrification of our energy use increases. We need more electricity to replace what we currently run on petrol, diesel, oil etc.

    MrNutt
    Free Member

    Given that we’ve had nuclear power stations for quite some time now, what have we been doing with the waste?

    Of course we should all actively reduce our consumption, demand will always be there but if we’re also generating power from clean, non damaging, distributed sources we will all ensure a better future for our children.

    TooTall
    Free Member

    if we’re also generating power from clean, non damaging, distributed sources we will all ensure a better future for our children.

    Nice dream, but not even close with current or near future technologies. Given the massive increase in electricity use once oil and gas run out, nuclear (several generations better than current and far more efficient so less waste) and renewables together are the most viable.

    MrNutt
    Free Member

    absolutely, its a transition period at the moment but it is completely possible with today’s available technologies to not only meet your demands but also export back to the grid half as much again. I have customers who have a 5kW wind turbine, a PV array and they are not only seeing their needs met but also receiving a sensible income from their energy generation.

    Trekster
    Full Member

    Trimix – Member
    Dont forget the FIT is there as a way for the electricity companys to offsetting the carbon they produce. Its like a tax on them.

    We are getting one fitted and expect to make £1200-£1300 a year. Big south facing triple (as in long) garage roof.
    My dual fuel bill is only £1200 atm so I would be making loadsa money if I fitted some panels?

    Reduce and improve efficiency. Don’t forget that as and when oil runs out, the electrification of our energy use increases. We need more electricity to replace what we currently run on petrol, diesel, oil etc.

    btw PV panels have a huge reliance on oil and gas for their manufacture 🙄

    Dupont Pv film made in the UK

    100mphplus
    Free Member

    My Uncle had 3.2 kw panels fitted first week in June, he’s already had a 3.7% return, on his ‘investment’ in 11 weeks, it’s a no brainer!!

    I’m just in the process of getting mine

    wonnyj
    Free Member

    Tootall,
    On panel efficiencies, I’ve found that 14-15% panels work out better than the best 17% efficiency panels on a capex price per unit of electricity generated.

    Trimix,
    You’re better off using the electricity and displacing the price of electricity from the grid than just exporting.
    You’ll get 50% of your measured generation “deemed” as an export at 3.1p/kWh anyway.

    TooTall
    Free Member

    btw PV panels have a huge reliance on oil and gas for their manufacture

    Manufacture once, use for 20 years – better than burning the fuel constantly to provide the same power. Under UK conditions about 2.5 years to ‘pay back’ the carbon consumed in solar cell manufacture. Not that huge really.

    wonnyj
    Free Member

    For those who have fitted already, did you hace any probs with connection to the grid?

    And how are you measuring output and submitting generation readings to ofgem?

    TooTall
    Free Member

    wonny

    I’ve just been measuring straight output power side by side and not looking too much at the cost TBH – max density as space is important for my work. I was just answering whether there was an iminent jump in tech.

    wonnyj
    Free Member

    Pretty hard to lifecycle assessment on pv due to uncertainies in the supply chain. But yes somewhere between 2.5 and 5 years is reasonable I’m told.

    NOt taking into account depletion previous metals etc

    wonnyj
    Free Member

    Tootall, fair enough when space is restricted.

    konabunny
    Free Member

    Power stations will soon be owned and run by the Russians.
    They held the Ukraine hostage.

    Ukraine (no “the”) is reliant on cheap gas from Russia for social stability (stop people dying in large numbers over winter) and to keep inefficient heavy industry going. There is only one pipeline which is effectively owned and controlled by the criminal-political-intelligence nexus at the apex of the Russian state. The gas transshipment industry in Ukraine is completely criminalised (Semyon Mogilevich, Turkmenbashi, Yulia Tymoshenko etc).

    The position in the UK is completely different.

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