So now I have a solar PV system how do I make the most of it???

Martyn1981

Helen18 wrote: »

Gosh, so much to consider...

Looking back at the figures you've suggested Mart, they are just a bit more conservative than those suggested on one of our quotes (I guess they're bound to make it sound as rosey as possible) but not far different so that all seems in order.

Great. That's the crucial starting point, so you have a rough idea of what might/should be generated, and can then work from there.

Quick points:

1. Hopefully people will suggest prices and ideas, but in the meantime here's a link to a recent thread, similar discussion to this, but does have a few recent install prices too:

https://forums.moneysavingexpert.com/discussion/4754866

2. Next, yes a lot to consider, and apologies if I've confused or overwhelmed you, but it will all start to make sense quite quickly. I promise.

3. SolarEdge (SE) and PO's (there are other systems). This allows a complete mix of panels, pitches, orientations, shading etc, as each panel is connected to a PO, so they don't effect each other at all. Here's a Youtube link explaining it (with parts 2&3 at the end, about 10 mins in total):

http://www.youtube.com/watch?v=lsa9rHpDVmQ

Here's a summary of my system after 1 year (just click on the white chevron):

Martyn1981 wrote: »

I think this just about scrapes in as generation(?)

Thought I'd give a little info on my WNW extension as it reached 1yr old today, and is, shall we say, a slightly unusual idea.

Cost wise the PO's cost about £40 (per panel) but the inverters are very high efficiency, are a couple of hundred less, and come with 12 year warranties. The PO's have 25yr warranties.

4. Don't blame you for not wanting to go over 4kWp, wise move. Also, with the better angle, I'd suggest only considering the east, if you do decide to do more than just the south.

5. More powerful/hybrids panels. I didn't explain this well, there are some leccy/hot water hybrid panels, but I meant the Panasonic or Sunpower panels that are more powerful per m2. They cost a lot more, but again, it's a numbers game, so worth comparing.

6. My guess to extrapolate a good quote, would be to start at £6k for 4kWp, allow an extra £500 for the SE kit, perhaps £200 for extra scaffolding if needed(?), another £200 for more complex railing system, given the number of starts and stops, £300 for a diversion switch (Immersun or similar). So around £7.2k. But this is really me pulling numbers out of the air, and will depend on who you can find, and how busy they are.

If you don't mind me asking, what is your approximate location, just county, or nearest city? Those generation figures suggest, to me, midlands(ish).

How's the headache - have fun.

Mart.

Helen18

Well, spent all day getting my head round all this and do feel like I'm getting somewhere....

Read rest of these threads and then some which pages. Spoke to guy from one company who really felt it wasn't worth adding more than the 12 panels.

Discovered that the scaffolding element of both our quotes was very significant so began to research possibility of the Sunpower panels to see if price is better than adding to east roof.

Got some more quotes from evoenergy which were much more in line with your suggestions here and on the which guide.

We're not really midlands btw, further north, nearish to York not far from the edge of the wolds.

Beginning to feel very tempted by these Sunpower panels. Price comes in at £9.6k so steep but if the claims are true they sound good.
Wonder if anyone has any experience?

Price of quote is pushed up by having two pitches on roof and it being split into two places which also adds to scaffolding costs and it's a bit awkward as beyond another single storey roof. Also we have slates which takes longer to install on according to evoenergy - do say if anyone disagrees!
Their quote for 12 panel system (not Sunpower) on south roof was £5600 ish so that seemed a lot better so I'm presuming the quote for Sunpower is also reasonable.

Advantages seem to be:
Can just put panels on south roofs and achieve better generation than 16 panels split across south and east roofs

Performance of panels is better so on a 3.92kwp installation we can get higher FIT, maybe nearer to what might have been achieved with 5kwp system but getting FIT at 4kwp rate. Is that right anyone?

Apparently panels don't degrade over time and have 25 yr warranty.

Supposedly you can expect about 10% more generation than what is quoted. Not too sure I'm totally convinced by this - if it's true, why can't they quote it? But given our steady aga consumption, getting max generation has to be a bonus and might allow times in better weather when other devices could be free too, or almost.

It is a bigger outlay but as long as they do what they say on the tin, we'd break even in 9 years at most and then continue to benefit so compared to a bank account seems reasonable. Still not quite sure whether to gamble on this or go for cheap and cheerful but I do tend to always want the best when I buy anything and would probably regret cheap and cheerful. Not quite sure how to come to that conclusion really.

I'm thinking maybe leave the immersun type devise for now and monitor how much, if any, useful spare generation we get and hope the prices come down too.

One thing that concerns me is the little bit of shading we'll get at times from next doors roof. Will this bring the performance of all panels down? Can we add optimisers to any panels? Prob expensive to do though if £40 per panel. Or can inverter cope with this?

Any knowledge of evoenergy as a company would be appreciated. They seem to have won a few awards and seemed to know their stuff (or maybe that's slick sales patter) and quotes and load of info were sent in 40 mins which is much better than other companies. Will do free survey to confirm costs etc. is there a catch???

Hx

tunnel

Hi Helen18,

Try searching solar pv system in ebay! There's a few installers on there like this one http://www.ebay.co.uk/itm/Sunpower-4kW-12x-327w-Black-Solar-Panel-PV-System-installed-MCS-and-EPC-3-92-kw-/181217747233?pt=UK_Gadgets&hash=item2a316b6121

Don't know how far north these will go but you get the idea. A 4kWp system should start around £5kish then increase by what you add on(panel type,inverter..etc, etc).

PS £9.6K......too much..... try harder

Helen18

Thanks tunnel,

I will look but I'm not sure I can bring myself to buy something this major on eBay! I suppose it shouldn't make any difference, I buy plenty of other stuff there but I would prefer to find a company with a really good reputation and after sales care. Will look on eBay and elsewhere for other quotes though.

Thanks for the advice
Hx

John_Pierpoint

The basic PV panel installation is a one day job for (say) three people:
The gopher, .the tiler (who knows how to walk about on a roof without falling off), and the electrician
The qualified one is the electrician.
Obviously if you know nothing about electrical installations in domestic properties,. you could be a victim of "b*llsh*t baffles brains".
There is no rocket science involved, a competent DIY person could do it, if it were not for the European wide regulations about almost everything needing to do done by a registered expert person.
Every installation team has to have a MCS registered person overseeing the work.

Having said that there are still "cowboys" involved in the business, they tend to be the salesmen.

I suppose an analogy could servicing the family car (a much more complicated piece of electronics):
The main agent probably has a new space age building, potted plants and a receptionist BUT is the grease monkey actually working on your car more competent than the owner managed business operating out of a Victorian railway arch?.
Who services the taxis in your town?

Helen18

Hi John,

I agree, the tricky thing is finding the bargain mechanic under the arches! I guess usually that happens by word of mouth but I don't have any friends who have solar pv and the couple of acquaintances had theirs installed years ago and certainly don't know anyone with Sunpower panels.

I've been researching more into these panels and the company and they are still sounding good but I don't know how to find the best price from a well established company with good reputation and after sales support other than randomly picking from the Internet. I'm finding lots of companies in the south at the mo who fit Sunpower but not so many near us.
Hx

Martyn1981

Hiya Helen. been having a ponder about your last post. Got a few bits and bobs, but more thoughts and numbers, so ignore if the head is spinning too much.

Firstly, comparing prices (retail before VAT), it looks to me as if the Sunpowers or Panasonic's are about 50p/Wp more expensive than YingLi panels (roughly 62p/Wp v's 110p/Wp). I chose YL's as they are very common. So for a 4kWp system you are paying roughly £2k more. The extra cost effectively buys you smaller panels relative to output, allowing you to squeeze more on. They may also perform slightly better, hard to tell.

Nothing against this option, but might be worth you considering (asking around) about YL Panda series panels. I think they go up to 280W, but 270W are definitely available (I just found a retailer with 500+ in stock). You won't be able to max out the 4kWp tariff band, but 3.24kWp (12*270Wp) isn't bad at all.

Back to shading, shading on some panels will drag down performance of all the other panels on that string. You mentioned splitting the panels across the roof (as well as across roofs), so ideally the 'set' on the shaded side would be on one string and the others on a second. Nothing complex about that, and a normal dual MPPT inverter that treats them as two systems.

However, if the panels are to be split left/right and 20d/40d roof, then that means 4 strings? The inverter won't be able to do this, not enough MPPT's, and probably not enough voltage per string to reach minimums.

So, I'm really not trying to 'sell' the idea of PO's (or micro-inverters etc) but if the shading is significant, then that might be the route you need to take.

Cost wise, I wouldn't worry about it, for 12 panels, that'll be £500 more for the PO's and perhaps £200 less for the inverter. But the better performance (have you read my 1 yr summary?) should make up for this ...... if ...... there is a shading issue. If shading is negligible, then the better performance may not be enough to make up the money.

To me, the cost of a SE system is worth it, the real issue is having (in your case) 12 extra bits of kit on the roof (albeit with 25yr warranties).

My SE system was installed by a company based in Rochdale, being more your neck of the woods, they had a very, very long drive to Cardiff, but they were the only people who both specialised in SE, and were willing to listen to my 'odd' idea. Slates and tiles are slightly different, and I felt that they did a much better job (on my slates) than the company that did my original (ESE) installs.

Only used them once, so whilst they were very good, hard to recommend openly, but happy to supply details if you want via PM. Let me know.

Don't worry and don't rush. If you aren't sure about any of these ideas, quotes, companies etc, then take your time. The best generation for the year is over, and it just slides downhill from here for another 2 months.

The current FiT subsidy is safe till 1/1/14 at the earliest, and even then if it does drop, it'll likely 'only' be by 3.5% to about 14.4p. Don't Panic!

(Apologies for the lengths of these posts, just too many thoughts and ideas.)

Mart.

Doc_N

Just a thought, Helen - IKEA have recently started a solar panel installation service, using Hanergy as the installer. Prices are supposed to be reasonable (with a 15% discount for IKEA Family Card holders) but I think at the moment the service is only available at the Southampton and Lakeside stores.

Might be worth checking out as a possibility:

http://www.ikea.com/gb/en/store/southampton/thebigtwofive

Tesco did ours back in 2010 (Mark Group did the installation for them). We've been well pleased with the system, and they did a really good job of installation, but I suspect they're no longer doing solar installations.

tunnel

Helen18 wrote: »

Thanks tunnel,

I will look but I'm not sure I can bring myself to buy something this major on eBay! I suppose it shouldn't make any difference, I buy plenty of other stuff there but I would prefer to find a company with a really good reputation and after sales care. Will look on eBay and elsewhere for other quotes though.

Thanks for the advice
Hx

Helen,

I only gave that link as an idea. I'd guess that the companies advertising on ebay are only doing so as its a very cheap form of advertising, probably costing a few quid compared to an ad in the papers costing hundreds. Most have links to their own websites.

Most companies that are still around will also probably still stay around not like the hundreds that popped up for the goldrush a couple of years ago when the FIT was offered at its maximum rate(just over 43p). Quite a few have fallen by the side, my installer included(luckily he's a damn good electrician so I know if there's any probs I can still call on him)

Take your time, as Mart says, if the rate drops in January, it won't be by a great deal!

zeupater

Helen18 wrote: »

... Beginning to feel very tempted by these Sunpower panels. Price comes in at £9.6k so steep but if the claims are true they sound good ....

... Performance of panels is better so on a 3.92kwp installation we can get higher FIT, maybe nearer to what might have been achieved with 5kwp system but getting FIT at 4kwp rate. Is that right anyone?

Apparently panels don't degrade over time and have 25 yr warranty.

Supposedly you can expect about 10% more generation than what is quoted. Not too sure I'm totally convinced by this - if it's true, why can't they quote it? But given our steady aga consumption, getting max generation has to be a bonus and might allow times in better weather when other devices could be free too, or almost.

It is a bigger outlay but as long as they do what they say on the tin, we'd break even in 9 years at most and then continue to benefit so compared to a bank account seems reasonable. Still not quite sure whether to gamble on this or go for cheap and cheerful but I do tend to always want the best when I buy anything and would probably regret cheap and cheerful. Not quite sure how to come to that conclusion really.

I'm thinking maybe leave the immersun type devise for now and monitor how much, if any, useful spare generation we get and hope the prices come down too ...

Hi

Depending on how you use your AGA (seasonal/temperature etc) chances are that you'll have such a high base-load that there will be no/very little extra generation to be used elsewhere in the home on all but the sunniest days ... one of my neighbours has an electric AGA and it keeps the kitchen pretty toasty all year long ...

Anyway, the increased efficiency of the Sunpower modules you are looking at really only give the advantage of placing more generating capacity on the same area of roof. A 4kWp Sunpower system will therefore provide similar annual levels of generation to any other 4kWp system using decent quality panels, so they certainly will not provide the equivalent of 5kWp ... it's just that having a 330W panel which is the same footprint as a 250W alternative will provide ~32%(330/245) more power, so 4kWp + 32% = 5.3kW is incorrect if you can't physically fit 16 panels of either type on the roof. Hopefully, you'll understand that what I've tried to explain is that you simply cannot account for the efficiency gain twice ...

Regarding the performance of the panels, you'll find that the main element affecting long-term performance (other than shade & weather ) is grime on the panels. If you have a reputable manufacturer's panel with self-cleaning glass the impact will be reduced, but beyond that, every silicon wafer will degrade by some extent, it's just that some makes define this in various step forms, whilst others do so as a straight line ... You'll probably find that in the real world there'll be a pronounced reduction early on as a normal level of grime builds on the pristine (ex factory) panels, followed by a gradual loss over time.

HTH
Z