Solar PV Quote seems excessive

Ageing_Stick_Insect

Hi Martin,

I've written to my latest quoter pasting your suggestion on panel layout. Many thanks for that. He had only looked at 1.6 x 1.0 Panasonic panels so it will be interesting to see what he thinks of your proposal.

I await his reply with considerable interest. I hope he doesn't think I'm the customer from hell!

Martyn1981

Ageing_Stick_Insect wrote: »

Another thing which I find confusing is the quote saying a System Size of 3.5KWp. I took that to mean that's how much I would generate. Wrong! It's actually 2.895kWh but that is under scrutiny as things stand.

I'm glad we're all agreeing now on the generation figure. On such a marginal install that 10% was concerning me.

Don't get your kW (power) and kWh (energy) confused. A 3kW kettle draws 3kW of power, but if only on for 2 mins will consume 3kW *2/60 = 0.1kWh or 100Wh of energy.

The PV system will be rated at it's maximum power KW, which itself is caveated at 25dC (I think) with the sun lining up well horizontally and vertically to the panels.

What a system actually generates in energy kWh, will depend on location, orientation, weather, pitch etc etc etc. South facing, southern UK should work out at about 1,000kWh per kWp pa. Southern Spain would be around 1,500kWh/kWp, and so on.

Ageing_Stick_Insect wrote: »

I'm beginning to think my roof is borderline for solar power generation with a decent return over 20 years.

Ummm, yes. That's kind of the conclusion I came to yesterday looking at the numbers, but didn't want to spoil your fun. Whilst income will rise with inflation, I'm not sure a starting point of ~£600 (if we're a little conservative, just in case) is going to be enough.

Your location, and orientations, are pretty decent, but the size and shape of those S roofs, is just making it all a bit too hard.

Maybe you'll get lucky waiting and seeing what developments come along, and hoping that FiT degressions stay at about 3.5% every 9 months. But they are based on install rates each qtr, and could drop every 3 months, and by 3.5%, 7%, 14% and 28% if there is a rush.

T&S panels may well become more popular and come down a bit in price, but I suspect they'll always remain a specialist product with some price premium.

I'm even starting to depress myself now. Sorry Ray.

Mart.

Ageing_Stick_Insect

Martyn1981 wrote: »

Don't get your kW (power) and kWh (energy) confused. A 3kW kettle draws 3kW of power, but if only on for 2 mins will consume 3kW *2/60 = 0.1kWh or 100Wh of energy.

The PV system will be rated at it's maximum power KW, which itself is caveated at 25dC (I think) with the sun lining up well horizontally and vertically to the panels.

Explanation understood, thanks. I'm still a bit confused about the maximum power domestic installs are allowed before the FIT drops. Is it 4KWp or 4KWh? Whilst southern England is parity KWh increases over KWp in Spain. Stronger sun, obviously. So for a northern England install to generate the same Kwh as one further south more panels are required so our installs will always be more expensive won't they?

Ummm, yes. That's kind of the conclusion I came to yesterday looking at the numbers, but didn't want to spoil your fun. Whilst income will rise with inflation, I'm not sure a starting point of ~£600 (if we're a little conservative, just in case) is going to be enough.

Doesn't feel like fun at the moment but at least I haven't made any expensive mistakes thanks to you and tunnel.

Your location, and orientations, are pretty decent, but the size and shape of those S roofs, is just making it all a bit too hard.

Agreed. Bit of a bummer really - to get technical!

Maybe you'll get lucky waiting and seeing what developments come along, and hoping that FiT degressions stay at about 3.5% every 9 months. But they are based on install rates each qtr, and could drop every 3 months, and by 3.5%, 7%, 14% and 28% if there is a rush.

So the more popular pv becomes the faster the FIT drops! :eek: Where's the sense in that? Labour costs won't drop so it could become a dodo in a few years.

T&S panels may well become more popular and come down a bit in price, but I suspect they'll always remain a specialist product with some price premium.

And those triangular ones are probably perfect for the Italian market with the higher sun. They need to have a 35 degree side for the UK market.

I'm even starting to depress myself now. Sorry Ray.

Mart.

Don't apologise Martin. You've opened my eyes and could potentially have saved me a fortune. No response yet from my quoter. What he comes back with will be a make or break choice I think.

Ageing_Stick_Insect

Some more thoughts about a pv system up north...

The sun is lower in the sky so power generation is lower than further south. However, labour costs probably aren't much lower and hardware costs definitely aren't so returns will always be less. That's no-one's fault - just circumstances. It's interesting to note that all the installs I've seen so far were done when the FIT was much higher than now. That means making a profit is much harder.

To generate the same power as a station further south requires more panels so cost is higher. Really, the FIT rate should increase further north to compensate for the reduction in power that can be generated. Sadly, this will never happen. So southerners get a much better deal than those further north.

My quote was for a 3.5kWp system - just 0.5 off the maximum for domestic installs. Given the shape of my roof with increased dead area over 3 roofs it is always going to be difficult to get the max for a relatively small house. Panasonic 1meter x 0.8meter panels may push it up to 4kWp but for additional cost... maybe.

Martin and tunnel, I'm assuming you have someone at home during the day to use the power your systems generate? I am retired and use a fair bit on 3 computers for flight sim and occasional daytime TV viewing on a plasma (power hungry). Then there's cooking, vacuum cleaner etc. so I'll be using a fair amount of the power I generate and given the cloudier skies possibly more than 50% of what I generate.

If my quoter can accommodate the Panasonics and if I can beat him down a bit it may still be worthwhile.

tunnel

Wife's at home all day so can take advantage of any unexpected spells of sunshine.


Cloudier skies Ray and you'll probably use all your generation, not just 50%, it's when the sun shines you'll struggle to use it all. But as Mart has explained, if you utilise ALL 3 rooves you'll keep a longer sustained generation all through the day instead of a large surge midday. Much better and more of the reason I have an array on my WNW, its not going to make me rich any time soon but will keep generating long and hard into the summer nights.

Martyn1981

Ageing_Stick_Insect wrote: »

To generate the same power as a station further south requires more panels so cost is higher. Really, the FIT rate should increase further north to compensate for the reduction in power that can be generated. Sadly, this will never happen. So southerners get a much better deal than those further north.

Yes, sort of. But playing Devil's Advocate, the counter argument is to encourage the technology where it will generate the most. So you could have a lower tariff in the south, of perhaps 8p to 10p that works for simple south facing installs, and nobody else can take part. I've pondered exactly the same idea as you, of a tariff that encourages systems where generation is tougher, but how to make it fair. Perhaps a tariff linked to generation that reduces as generation rises. So maybe, 20p for the first 1,000kWh, then 15p for the next, then 10p, 5p and 0p. But any system will draw inevitably draw new criticisms.

At least the north has better wind, but whilst I'd love a wind turbine, from what I've learnt from off-griders, it's a labour of love, and siting is absolutely crucial, making small domestic units pretty tricky. Hard as it might be to believe, I'm just not full of wind .... enough!

Ageing_Stick_Insect wrote: »

Martin and tunnel, I'm assuming you have someone at home during the day to use the power your systems generate? I am retired and use a fair bit on 3 computers for flight sim and occasional daytime TV viewing on a plasma (power hungry). Then there's cooking, vacuum cleaner etc. so I'll be using a fair amount of the power I generate and given the cloudier skies possibly more than 50% of what I generate.

50% is seriously tough, unless you use a diversionary switch to heat water, but that will mean gas, not leccy price savings. Can you change the telly? Last year we went from a not too old 32inch LCD to a 39inch LED. Power dropped from 181W to 54W.

I reckon we used 33% of generation last year (1,400kWh:4,250kWh).

Ageing_Stick_Insect wrote: »

If my quoter can accommodate the Panasonics and if I can beat him down a bit it may still be worthwhile.

One more idea! My ESE roof was a pig. It looked good on paper approx 6m by 5m, with 5m by 4m useable. But due to a large Velux it was a nightmare. 1m to the left of Velux, and 2m to the right, so landscape was out. And 2.7m under the Velux. But I then discovered 1m by 1.3m panels. So perfect fit width, height and even under the Velux.

My head is still hurting from this morning's calcs, but if they are available, would those panels work any better? They'd probably be about 190Wp to 200Wp (mine are 185Wp).

I can't find any on the sites, but they must still be around ..... I think?

Found these, but it's a .com site. You'll need to ask the installer IF and only IF they slot in better. You need about 20. Good luck.

http://www.yinglisolar.com/en/products/multicrystalline/yge-48-cell-series/

Mart.

Martyn1981

Here you go Ray, only 50p/Wp (before VAT) really cheap, but there is only one available ...... still it's a start, at least they are out there:

http://www.navitron.org.uk/product_detail.php?proID=604&catID=138

here's another 7, but 5 less Watts

http://www.navitron.org.uk/product_detail.php?proID=575&catID=138

Mart.

Ageing_Stick_Insect

Martyn1981 wrote: »

Yes, sort of. But playing Devil's Advocate, the counter argument is to encourage the technology where it will generate the most. So you could have a lower tariff in the south, of perhaps 8p to 10p that works for simple south facing installs, and nobody else can take part. I've pondered exactly the same idea as you, of a tariff that encourages systems where generation is tougher, but how to make it fair. Perhaps a tariff linked to generation that reduces as generation rises. So maybe, 20p for the first 1,000kWh, then 15p for the next, then 10p, 5p and 0p. But any system will draw inevitably draw new criticisms.

Probably why they didn't bother and just have a standard rate across the country.

At least the north has better wind... Hard as it might be to believe, I'm just not full of wind .... enough!

Far more difficult to get it converted into electricity I guess. We have enough of those blasted turbines anyway. Domestic ones would be a nightmare. And no, of course you're not.

50% is seriously tough, unless you use a diversionary switch to heat water, but that will mean gas, not leccy price savings. Can you change the telly? Last year we went from a not too old 32inch LCD to a 39inch LED. Power dropped from 181W to 54W.

tunel thought I'd use most of what I generate especially as it's spread over 3 roofs. Morning - shower and washing, afternoon, flying on the computer and evening - watching TV.

Love plasma, hate picture LED gives although they're better than a few years ago. Until plasma stops working I won't change it.

I reckon we used 33% of generation last year (1,400kWh:4,250kWh).

Until you've had 12 months usage it's hard to tell how much would be used during daylight hours.

One more idea! My ESE roof was a pig. It looked good on paper approx 6m by 5m, with 5m by 4m useable. But due to a large Velux it was a nightmare. 1m to the left of Velux, and 2m to the right, so landscape was out. And 2.7m under the Velux. But I then discovered 1m by 1.3m panels. So perfect fit width, height and even under the Velux.

My head is still hurting from this morning's calcs, but if they are available, would those panels work any better? They'd probably be about 190Wp to 200Wp (mine are 185Wp).

Mart.

Are you referring to 1.3 x 1.0 panels? I haven't done any calculations. Like you my head is hurting and I'm still waiting to hear from the quoter. I'll mention them when he gets back to me.

Thanks once again.;)

johnel_2

Going back to the above about pricing. I just had a 16 panel microinverter system fitted for £7000. German panels plus Enphase inverters. We got quotes ranging from £5999 for cheap panels with cheap inverters, right up to £9200. Some did not even talk about the inverter options and only went for the big box inverters. Best to do your homework and ask for references. The scaffolding is a bit of a scam too. Some wanted up to £500 on top. The one we finally used quoted £200 on top, but the guys said they didn't need it and we got it knocked off the bill.

Martyn1981

Ageing_Stick_Insect wrote: »

Explanation understood, thanks. I'm still a bit confused about the maximum power domestic installs are allowed before the FIT drops. Is it 4KWp or 4KWh?

Hi Ray, the rates are upto 4kWp, then >4-10kWp.

So it's what you've got installed on your roof, not what it generates. [Technically, it's defined in legislation as the maximum amount that can be continuously produced, so it should really be defined against the inverter rating, if it's capped lower. But OFGEM guidance doesn't necessarily match the legislation. There's a shocker.]

Ageing_Stick_Insect wrote: »

tunel thought I'd use most of what I generate especially as it's spread over 3 roofs. Morning - shower and washing, afternoon, flying on the computer and evening - watching TV.

Tunnel did say that, but with cloudier skies. On long sunny days, when all the washing and vacuuming has been done, you'll be exporting a lot of green leccy to your neighbours whilst simultaneously terrifying and entertaining the beach goers on the other side of the fence from Princess Juliana International Airport.

Mart.