With up to £2,500 grant and Feed In Tarriff is seems to make sense to buy and fit before April next year (when the grant goes) to maximise pay back. I've done some sums and it points to a pay back period of 10 years – i.e saved / made more money than if I'd used the money to pay off the mortgage. That and it's renewable energy.

Anyone done this and have anything good or bad to say about it? Or even not done it 'cos it doesn't seem to be a good idea?

tks

I've been generating electricity this way for years. I have both a calculator and a watch. Brilliant idea.

No offence but please make sure the sums are done by someone in the know (if you are not).
Don't make the mistake of using the panels' rating to base the enrgy yield on. There is a lot of rubbish talked about Solar PV, get advice from the carbon trust or PM me and I'll do my best to answer any questions.

It is a great idea provided you can fund it and you have the basic requirement – a south facing roof. Energy is only gonna get more expensive, so generating some of your own will help. Feed-in tarrifs are not yet set (value wise) so hard to predict pay back. I have a colleague in france who will get payback in 7 years, from no grant but E0.30/kWh feed in. it would be less than that now coz silicon prices have dropped, but he is in south of france and has a perfect near 35deg south facing roof.

I'd go solar thermal first though.

Cheers

Andy

tks, might PM you in a few days.

if by solar thermal you mean heating hot water then don't think that makes sense for me – gas for hot water and central heating only costs me £350 a year with about £100 of that for hot water when the heating is off so reckon saving on hot water might be £100 a year if lucky which means pay back is a long time.

Have a south facing roof and done some in depth calculations but there are far too many variables to realistically get an accurate result – also when max electricity is being generated I'm out – I use 21% of total electricity on economy 7 when it's dark outside …..

I'm far from being an expert, but all I've seen photovoltaic makes no economic sense at all in this country unless the grants are good enough to cover most of the initial cost. Bear in mind that there is a huge difference in the sun incidence between here and the South of France (combination of basic sun angles and the fact we tend to get more cloud). As andy says you do need to factor in realistic derating factors – which are unlikely to be the ones provided by whoever is selling it.

Don't want to hijack this one, but is there a source of "sensible", unbiased information (ie, not someone with something to sell) on all of the various ways of self-generating power? I would love to know if anything is yet realistically feasible, but as the above responses suggest, there is a lot of tosh spoken to sell kit.

You'd be better off with a turbine, but only just. Solar Hot water is realistic and the payback time better.

If energy prices are 60% higher in 10 years though…..

If you can't get a good payback for solar water heating, you won't for PV, either. It's much less efficient.

Agreed, in the UK the sums do generally seem to stack up against PV due to the fact that we have relatively poor insolation due to our position on the globe, our climate and teh fact that rarely can people mount tracking arrays on their roof, so the actual % of insolation used is tiny. Add to that the fact that solar cells have a finite life and need fairly regular cleaning to remain efficient, you're looking at climbing a ladder ever few months to clean and possibly replacing them not long after they break even. Solar water heating seems to get more favourable returns, even in colder climes, but I've not seen the actual calcs on them so can't be sure and don't have the time to do them.
Wind turbines in an urban environment require a lot of thought in the location as there's plenty of energy present but not necessarily available, all too often you see turbines sat doing nothing or rotating wildly. Got a small stream?

keep on buying the panels guys, I work for a firm making the film inside them. Just qualified it for the euro standard of 25yrs. Recently picked up production hopefully due to the Spanish and Asian housing markets starting to move again

I looked at having a biggish wind turbine installed a few years ago but even with the maximum grant it was going to cost about £13k iirc.
We live in a rural area and are reasonably well exposed to prevailing winds (i.e. although not high there's no trees or buildings within 600m) so it could work out…….. just couldn't justify the payback timescales involved. Obviously rising power prices could mess up all those calculations.

Just qualified it for the euro standard of 25yrs.

Interesting, that is. We have some well-known-manufacturer ones that are supposedly fairly new-ish technology and they've yellowed and died after about 7 years?!

I am going to take a hard look very soon at the feed in tarrif and the governments commitment. There will be lots of installers doing it, if it takes off, and China will pump out the panels to reduce the price.

At the mo my elec is from Ecotricity so I feel reasonable lack of guilt about it, but I will look hard at this stuff. Lots of people (eg navitron) sell DIY kits, so don't get too carried away by Government grants either. Most of these grants are more of a backhander to the installation company than a genuine benefit to you if you have some DIY ability.

Trekster: What's your opinion of panel price per KWp over the next few years: got any steers?

Chaps

some facts:

feed in tarrif has been set – 36.8p/kWhr generated feed in tarrif for <4kW systems.
BRE allow an assupmtion of 800kW/hr generated for every kWp (peak) fitted in UK – it is possible to get 900kW/hr but you arent allowed to tell folk that if trying to sell PV.
south facing roof is not as vital to PV as it is with solar thermal.
payback is possible in 8-12 years depending on your daytime usage – the higher, the better the payback.
Solar Thermal DOES NOT have a better payback than PV – if you heat your water with natural(mains)gas then the payback can be 40 years. (say 50% 0f hot water free, 210 litre tank need 13.5kW/hr to heat, gas @ 3.5p/kWhr = 13.5 x 365 x 0.035 x 50% = £86. cost of system – £4K after grant = 46years 🙂

if i had £5k to spend on the house, i'd fit PV today. i dont so its a moot point.
what has been noticed is that the difference PV makes to your Energy Performance Certificate (EPC) part of the HIPS increases the value of your property by justabout the same as the cost of the PV – so if trust this info, and you aim to sell at some point, you can almost treat the PV like a bond where payback is immediate.

the feed in tarrifs are guarenteed for 20 years – there isnt another guarenteed way of doubling your money in 20 years.

HTH

job is in profile if anyone wants to discuss this further.

photovoltaic film

Trekster: What's your opinion of panel price per KWp over the next few years: got any steers?

Sorry, no idea. We just make a film that will be used to insulated the circuit boards apparently. Just a new product for us. Goes to somewhere in Germany. Not on the science side, I just keep the machines turning 🙁
It will however be detremined by the price and supply of gas, electricity and oil

BRE allow an assupmtion of 800kW/hr generated for every kWp (peak) fitted in UK – it is possible to get 900kW/hr but you arent allowed to tell folk that if trying to sell PV.

What is this kW/hr unit you're using? I'd think you meant kWhr, but that makes no sense in the context either. I'm looking for either a timescale if you're quoting energy produced, or a real power rating, as that really makes no sense at all.

south facing roof is not as vital to PV as it is with solar thermal.

No of course not – one which the sun hits at a very acute angle will be just fine 🙄

Hi Smudger "payback is possible in 8-12 years depending on your daytime usage – the higher, the better the payback".

Surely if you have high daytime usage, then you don't get to sell your power at £.368 becauase you are effectively using it? How is it that payback is faster if you use more daytime power? Surely the more you don't use, the more you sell at £.368? Am I misssing something?

– I should move over to the Green Building Forum at this point!

http://www.communities.gov.uk/publications/planningandbuilding/loworzero

The final report on low and zero carbon technologies. Not broadcasted!

Will you still be in the house in 10yrs ? If not your wasting the money. People buy houses because of size, price and locatiion. All the other things are very low priorities.

backhander – interesting, suggestion only microCHP plants are cost effective, yet then later saying cost effectivity studies should not be broadcast in case they are taken out of context?

PV:

Only façade mounted
applications in offices are shown to be cost effective and only when the value of carbon
at £95/t is included in the cost saving

Wind turbines:

None of the applications are shown to be cost effective

Intro to cost effectiveness section:

It is recommended that the cost-effectiveness assessments are not made available as part
of any consultation exercise since they have served their purpose within this report and
could easily be misinterpreted outside the context this purpose.

Classic!

"If not your wasting the money." (sic)
I don't think investing in renewables should ever be called "wasting the money". For those who can afford it, that type of investment is not "wasted" if it reduces their carbon footprint. There are plenty of people willing to pay a lot of money to do this, irrespective of whether it "pays off".
Fossil energy is too cheap. That's the problem which leads directly to "wasted money" argument.

I beleive that this report was compiled by Faber Maunsell, who are by no means idiots. During my low carbon consultant training it was indicated that this report does not sit comfortably with the powers that be.

I don't think investing in renewables should ever be called "wasting the money".

Not even if you're looking at it from a cost effectiveness viewpoint? Is that what we're now reduced to – it's not allowed to even consider such things when you're "saving the planet"? Even if you could reduce your carbon footprint by more for less money by doing something different?

Even if you could reduce your carbon footprint by more for less money by doing something different?

In that case, I agree of course it makes less sense. – You mean not driving the SUV, and turning the boiler down instead. Indeed, but it's getting people to act this way, that's the problem.

No, I mean spending the money you might have wasted on PV cells on insulation (for example) instead. Your examples are irrelevant, given they save you money (and save energy) without having an initial capital investment.

Be very careful if you want to buy into the domestic renewable energy market at the moment. The difference between what the devices are rated to and what they produce in the real world can be huge. We have actually found it quite difficult to get any data from domestic installations as very few have proper monitoring in place but where we have they suggest that people are only getting around 10% of the rated value of the equipment. For example we know of a house with a sizeable 4kW/hr solar water heater on its roof. The data collected showed that during 12 months its output ranged from 13 to 180 kW of electricity produced per month. So even in the best month it is producing far less than 1kW/hr.

Also don’t forget that you may need to factor a few other things into the cost such as an inverter to allow you to connect the device to the grid, a two way ‘smart’ meter to measure how much electricity you are not using and maybe planning permission.

If you are thinking of wind turbines then you might like to read this…
http://www.which.co.uk/advice/wind-and-solar-power/wind-power/index.jsp

In my opinion if you want to reduce your energy bills and or carbon emissions then I would spend your time and money reducing how much you are using and wasting (insulation, better windows, low energy appliances etc.). Then in 3-5 years time buy one of the many mCHP appliances that’ll be on the market to replace your boiler (whilst not renewable they are very much low-carbon). Then hopefully in 10-15 years time we’ll have some truly viable domestic device for generating renewable energy.

I don't think investing in renewables should ever be called "wasting the money".

The thing you are forgetting is that producing the solar panel etc. has a carbon footprint. If that panel is actually producing far less energy than it was expected to then it will spend most of it’s life, if not all of it, just offsetting that carbon. You could end up actually increasing the overall carbon emissions!

Yes, and yes. Argument too simplistic. Agreed. 🙂

For example we know of a house with a sizeable 4kW/hr solar water heater on its roof. The data collected showed that during 12 months its output ranged from 13 to 180 kW of electricity produced per month. So even in the best month it is producing far less than 1kW/hr.

Is there any chance of getting your units straight? I presume you mean a 4kW heater, producing 13 to 180 kWhr per month, so producing less than 1kW average in the best month!

I do hope that you're including maintenance in your costings also.
Specialist equipment can be expensive.

ok

south facing roof is not as vital to PV as it is with solar thermal.

No of course not – one which the sun hits at a very acute angle will be just fine

hmmm, possibly some misplaced sarcasm there – read the sentence properly, then get sarky.

I said it wasnt as vital with Pv as with thermal – the thermal panels performance drops off more quickly than pv as you leave south and move towards east/west. so long as the PV isnt in shade it will generate reasonably close to its peak even if facing east/west – certainly a higher percentage of its maximum than a thermal panel at the same angle.

The daytime usage thing is as follows: you get paid for every kWhr(and yes, i was getting the unit incorrect) you generate – thats the 36.8p mentioned – whether you use it or export it. You then get an additional 5p per kWhr if you export it to the grid. total – 42p per kWhr generated and exported. if you are using it as you generate it – i.e. peak rates during daylight, then you are offsetting the cost of the power used – up to 12 or 14p depending on your peak tarrif – potentially 50p ish per kWhr generated and used.

as for the different units….

Solar PV is measured in KWp – Kilowatt peak – thats the theoretical maximum power it could generate at noon in the sunniest days. the amount of energy produced by 1kWp of panel is anywhere between 700-900kWhr/annum depending on your location within the UK. BRE say best practice is to base payback calculations on 800kWhr/annum.

Is there any chance of getting your units straight?

Sorry, I always get the units wrong unless I stop to think about it. I don’t come from a heating background so can’t understand what is wrong with using Joules?

Out of interest Smudger666, to balance the above figures which you suggest would save ~£400 a year (and maybe more if you include ROCs), how much would it cost to install a 1kWp system including all the additional wiring, inverters, maintenance etc.

I do agree that the new feed in tariffs do make generating your own energy look far more appealing (especially for wind and PV) and will undoubtedly increase sales as they have done in Germany. However I also think that people are not necessarily being presented with the complete picture.

Whilst the above example might be putting a significant amount of money back in your pocket now it might only be accounting for a relatively small amount of the household’s energy consumption. That means that any significant increase in energy costs from the utilities will quickly eat into that ‘profit’. In addition, you might not be reducing your carbon by that much (especially if you include that used to pay back the cost of the equipment) which is the whole purpose of the tariffs in the first place.

max cost in the market at the moment is £5,500/kWp + VAT – maximum because if an installer quotes higher than this AND the client is going for a grant, they have to get 3 quotes. so long as the price is 5.5K or less, then the grant application goes through ok with just the one price.

jobs of 3-4kWp can come in at a lower cost per kWp.

you have to be careful of prices that arent complete systems – I've seen prices in the £2/watt range, but that didnt include roof mountings, installation or the inverter etc.

and maybe more if you include ROCs

Er, no ROCs at FIt levels. That's the point of having the FIT..!

I'm not convinced we'll get FIt when promised – the consultation has only just finished, and I'm fairly sure the election will slow things down.

Actually, on the election – and this will be of interest to those like Smudger who work at that level of the sector – the Conservative Party's policy statement on energy is due to be published by end of November this year (and definitely before Christmas, according to an insider I spoke with last week) and is set to favour micro generation (as well as offshore wind, tidal and wave – onshore wind is too difficult for them).

I'm very in favour of FIT – look how succesfulk it has been in Germany, where they are set to achieve 4.5GW installed capacity with PV alone by next year. OK, sure installed capacity doesn't equal output, but it does indicate that there is a market for small scale sale of pwer into the grid.

Also, smart metering is increasingly going to be rolled out. Right now, it only really exists at any sensible level at the half hourly metered level, though is rapidly being installed by British Gas and RWE at the large business and increasingly into the SME market. Domestic is also being trialled.

I also work in this sector – thought from the legal POV. Want to know more, mail me via profile.

Tom

tks for the replies. My few notes on it.

Capital outlay
Cost of 2KW system @ 10k
Grant = £2,500

I’ve no idea if the grant has artificially inflated the costs and these will reduce once the grant goes. Also systems should (?) get cheaper as technology improves and more units made/sold to bring in economies of scale.

This outlay has to be funded somehow so you’ll either be losing interest on it if saved/invested for the long term or if added to mortgage then paying @ 2.5% interest at current rates. Hard to predict what future interest rates or investment returns will be.

Annual Costs
Annual Maintenance – maybe just a clean but no system is fool proof so no clear idea of what this will entail. Maybe have to replace a panel.

Insurance – haven't checked but fairly certain there will be little or no charge on your buildings insurance.

End of Life of system
Decommissioning – don’t know how long the system will last before needing to be replaced or also what costs this will involve. Maybe some environmental tax to get rid of old panels etc.

Annual Income
1) FIT @ 36.5p per unit generated for 20 years – but this hasn’t been set yet, could easily be reduced / removed by a Government that needs to claw back budget deficit and I don’t know if it will be treated as taxable income so could reduce by 20/40%. Also this figure is reduced the longer you put off buying the system.

2) Energy generated & not used so fed back into the grid @ 5p per unit. This rate may change either up or down over time.

3) Invest the money made each year but also factor in the money not spent if you didn't have PV panels.

Energy expenditure
Energy need above that generated and taken from the grid @ what ever tariff you’re on. 15 – 20 p/unit ? Difficult to predict where prices will go but IMO they will show a rise over any future 5 year period.

Energy Consumption
1) During the day when the cells are generating most electricity it’s best to be using the most in the home. At night, you want to be using the least energy as you’re generating none. So the split between day and night usage affects the pay back.

2) over time your energy consumption may change – could go down as you use less 'cos of better appliances or may go up if you start a family etc.

Effect on house prices
Not got any independant view on the effect of house prices. As said above most people don't stay in a house for a long period of time.

Non monetary stuff
1) How much you put on "being green"
2) If we do suffer energy shortages in the future or power strikes like the 70's then you'll have some security of your own electricity at certain times of the day !!!
3) It's very much an emerging market with a few cowboy installers. Pick the wrong panels and/or installer and it'll be bad.
4) Figures from someone who's had PV panels for a year are: rated 1440, generated 1186 which is 82% efficiency.
5) What actual guarantee do installers offer? Is it an insurance backed one so if/when the installer goes out of business what happens.

Overall I think there are too many variables or future unknowns to predict an accurate pay back period. I could probably invest the capital in the stock market over 20 years and make more money than I'd save by installing a system. And that system has a finite life where as the investment would keep on growing. But, from my figures I reckon 10 – 15 years for me.

As for wind turbines – Warwick council did a one year trial and the only ones that generated any usefull electricty where on top of small blocks of flats…..and the residents had them taken down 'cos of the noise generation !!! At the moment I've seen no independant evidence to say urban wind turbines are cost effective or in fact effective at energy generation.

Double post !!!

I've seen no independant evidence to say urban wind turbines are cost effective or in fact effective at energy generation

Chatting to a chap today whose business is in that end of the market – usually, I deal with developers of huuuge wind farms – and he reckons that the urban environment is not hte best place for them. He said, if you live somewhere with decent wind, and have a field, it's a whole lot more of a sensible proposition.

I think solar thermal has benefits, but of course it's inefficient on a domestic level – too much to produce hot water, not enough to heat the house. Shame we don't have district heating in the UK….

Micro CHP is *ptobably* a good answer, but it currently relies on natural gas, and we rely too heavily on Gazprom as it is….

Good luck with it, DaveGR. You're doing everyone a favour by examining this. The more of us that do it, the greater the take up and effectiveness of renewable power production.

In addition, you might not be reducing your carbon by that much (especially if you include that used to pay back the cost of the equipment) which is the whole purpose of the tariffs in the first place.

I think you've misunderstood. The whole point of the tariffs is to try and help the UK reach its nominal target for generating electricity by renewable means. I don't think there's any consideration of the carbon cost of manufacturing, installation etc., since that's not included in the target, so they don't care about that.