Solar PV Panels and the Feed in Tariff (FiT)

Anyone had any first hand experience with their own sloar PV installation. Do they perform as promised? Are the returns from the Tariffs as hoped? I am looking to install a 4kWp system of Sanyo Hybrid Panels (max. without seeing a drop in FiT) with a Sunnyboy 3300 inverter and any advice that is NOT from an installer with a vested interest in the technology would be appreciated. Paul from West Bridgford

RichardW

First I would suggest that you ask the same question over on the Navitron forum. You will get user & installer advice.

If your budget can stretch to a larger install it still make sense even with the lower FIT's rate as the install per kWp is cheaper.

Most people are finding that this year there systems are exceeding the expected production. But then they might also have years where it is less.

The biggest worry for most people is the government & that they often go back on promises.

Why would you fit 4kWp of array & a 3300w inverter? Whilst there are some reasons for fitting a slightly small inverter you would be wasting the bulk of the best days production. Yes you can input 4kWp but it will only give out 3.6kWp

Quote:

Input current
Rated output: 3300 [W]
Maximum power: 4300 [W]
Maximum power tracking window: 200 [V] - 400 [V]
Maximum voltage: 400 [V]
Max. input current: 20 [A]
DC input: n/a
Number of MPP trackers: 1
Output
Voltage: 230 [V]
Nominal capacity: 3300 [W]
Max. capacity: 3600 [W]

A very rough guestimate would put your lost income at about £60 per year (or £1500 over the term) plus you will need to buy in more electric as well. As inverters dont increase in price that much I would go for the next size up. Say the 3800 (plus €30) or 4000 (plus €350) (yes € not £)

High PV cell efficiency will not always be a good thing unless you have a limited roof space to mount them on. You pay extra for them yet the kWp will be the same as a cheaper panel. The only saving is on space.

xpaulx

RichardW - Thanks for taking the time to reply, and maybe you can tell me whether the advice I am getting is suitable given some of the points you have touched on in your post. The exact size of the array is 3.82kWp, I can get up to this as a maximum using a hybrid panel on the area of roof I have. The inverter, I am told a SunnyBoy 3300 is the most appropriate, being in the UK, again I am told, there is a solar factor efficiency of 0.8, (i.e. the same panels in UK do not perform as well as they do in Spain). Therefore a 3.82kWp array can only actually acheive 80% percent of the potential 3.82kWp power from the panel - thus the SunnyBoy3300 has been recommended - Am I barking up the wrong tree? or does this sound right? (It does sound logical, otherwise manufacturers would need to market the same panels with differing outputs depending where they are selling them). The SunnyBoy 3300 literature says that it is suitable upto a 3.82kWp system presumably for this reason in the UK? Any thoughts on what I have been informed would be very welcome as I am trying to diserfer the best available to me. Paul from West Bridgford

RichardW

1, The exact size of the array is 3.82kWp, I can get up to this as a maximum using a hybrid panel on the area of roof I have.

2, The inverter, I am told a SunnyBoy 3300 is the most appropriate,

3, being in the UK, again I am told, there is a solar factor efficiency of 0.8, (i.e. the same panels in UK do not perform as well as they do in Spain).

4, Therefore a 3.82kWp array can only actually acheive 80% percent of the potential 3.82kWp power from the panel - thus the SunnyBoy3300 has been recommended -

5, Am I barking up the wrong tree? or does this sound right? (It does sound logical, otherwise manufacturers would need to market the same panels with differing outputs depending where they are selling them).

6, The SunnyBoy 3300 literature says that it is suitable upto a 3.82kWp system presumably for this reason in the UK?

Sorry had to break it down a bit as your post is very hard to read in one big block.

1, Fine, if you do have size limitations then a better efficiency panel helps you to get more in less space (still not sure the extra costs stand up). How much will fit using standard panels? How do the costs compare & how does the forecast harvest & FIT's payments compare?

2, Now I know the array is 3.8kWp & not 4kWp then its much less of an issue. Not perfect & I would still look at the next one up as its only a few £ more.

3 & 4, That is sort of correct that we do get less sun (and it gets less the further north you go) but you can still max out your array when it is sunny for the midday period. My own 1.2kWp array can & has produced more than 1.2kW.

5, The panels are rated for power using a fixed light level that is the same for everyone. I think its 1000wm2. Then using the efficiency you can see how much power you can collect per m2. At 20% you are looking at 200w per m2. So again its size over area when it comes to efficiency. Less efficient, just fit more m2 (but the same Wp)

I would now not be to worried about the inverter with your array size.

They should be able to predict the harvest using different inverters so should be able to give you a quote on a few different ones.
It might be that they have stock of this one so want to use them. It could also be that they dont think that a small increase in power gained each year is worth it for the price difference.

But that is your choice to make not theirs.

moulesnfrites

As your array is 3.82 and the maximum DC power of the Sunny Boy is 3820 I would suggest an alternative inverter. The Sunny boy 3300 has a maximum efficiency of 95.6%.

I would suggest the Sunny Boy 4000TL which has a maximum DC power of 4200 watts but is 97% efficient. The TL is transformerless so runs cold.

I would also be very careful where you let your installer put the inverter, lofts seem very popular but are a very bad choice. The inverter will lose 3% of efficiency for every degree over 45 degrees and a standard inverter runs hot anyway. So a hot dusty loft fails to meet the requirements of the installation manual when you consider how hot lofts get during the summer when you want your PV system working at its best.

I dont really agree with the efficiency comment above as sanyo have the market topped with their modules at 20% compared to the likes of Sharp at 14%.

http://us.sanyo.com/Consumer-Solar/Product-Comparison

You will have a twenty five year contract with the power supplier of your choice and not the government so if the men in suits change their minds it will only affect people without a contact.

A better place to get information would be here as Navitron are basically a sales company .

http://www.electriciansforums.co.uk/photovoltaic-solar-panels-green-energy-forum/

or here

http://www.yougen.co.uk/

RichardW

You will have a twenty five year contract with the power supplier of your choice and not the government so if the men in suits change their minds it will only affect people without a contact.

A better place to get information would be here as Navitron are basically a sales company .

Do you have a source for that claim?

The N forum is not in the main limited to N employees there are plenty of fully independent opinions available on there from both sides of the installer / customer fence. Unlike most sponsored forums N let you get on with it.

Oh & even Sanyo agree its all to do with area

Quote:

HIT = More Power
More Power per square foot

You might have a point with the heat coeficiency but I have not looked at that yet.

They loose points in my mine with the claim about giving you more power when new. Thats just due to the amphorus part of the cells. Thats standard for all of those types of panels as they sharply drop when used. moulesnfrites

You may recall that the N forum started a petition against the MCS as it had loads of stock of imported non Ce marked, N badged, solar junk. It wanted an open market so unqualified personnel could fit untested imported rubbish and reap the benefits.

N now sells some MCS equipment and even started its own MCS signing off system so they seem to have gone full circle.

We have been on loads of projects where the N. junk has been fitted and we have on file a copy of the solar thermal install manual, the one that promotes silicon around holes in roof tiles !!!

laughable really ......

All I was doing was giving people a link to sites which do not have a sales angle.

http://www.yougen.co.uk/

is a good example, loads of information yummersetter

You will have a twenty five year contract with the power supplier of your choice

We've just been sent our EDF contract to sign. 16 pages of small print - terms, conditions and statement of terms. I bet buried in there somewhere there'll be a get-out clause should the government renege on the deal Rolling Eyes

RichardW

As the FIT only pays for power (or should that be energy?) actually made then why do you need approved equipment. You only get paid if the items you bought actually work. Choose baddly & you get paid less. Just like in all other aspects of life.

I am still to be convinced that MCS & Real with actually benefit the consumer in any way. moulesnfrites

Quote:

I am still to be convinced that MCS & Real with actually benefit the consumer in any way.

I have loads of pictures of appalling PV installations all by MCS installers and seen quotes with ridiculous FIT return claims and having sat through a two hour Anglian windows PV presentation last Friday evening at my neighbours I am inclined to agree with you. Ideal solar and Everest on watchdog and Which report on bad companies and Real seem toothless.

Here is a link to my own sting on Anglian ....(It was very tough keeping my mouth shut ! Smile

)

http://www.electriciansforums.co.uk/photovoltaic-solar-panels-green-energy-forum/29694-tonight-should-fun.html

Just look at the Anglian prices and the quoted return on investment figures and tell me that the MCS and REAL are sorting out the rogue traders, blue chip or otherwise. RichardW

Do you know about the Real clause where if I say refer the customer to you I can make any claims I like & cant be held to account by Real?

Just checked your link.

OMG.

So would you now like a scheme that allowed anyone to install & then get it signed off either by the council inspector or even the Utilities company inspector? moulesnfrites

This is exactly what has hapened to the worst solar company in the UK according to which magazine.

Ideal solar had many smoothtalkers in suits making unbeleivable promises at very inflated install costs. Ideal appear on watchdog and which report and lose MCS.

Ideal fitters (all subbies) then get MCS registered themselves and now Ideal still send out the suits and can say what they like without fear as they are allready outside the system. Ideal is now an unbrella company without MCS.

Absolute disgrace, they are at least £5K above average PV price and this profit all goes back into their £200K a year advertising budget and leaflet drops to get the salesmans appointments to keep the ball rolling. RichardW

So the system is failing with & without the MCS / Real codes.

Not sure where to go from there Confused

moulesnfrites

Hi Rich
Here is a link to the two rogues solar companies getting ejected from Real.

http://www.which.co.uk/news/2011/02/solar-companies-suspended-245838/

As I stated above it has not stopped them, some of the subbies now have MCS on their own and Ideal are effectively now not in REAL and the high pressure salesmen can make any promises they like.......no change there then ! RichardW

But they got suspended & allowed to rejoin on probation so are free to carry on as long as they tow the line (or are more careful).

As 10 in 14 made misleading claims it does not bode well for the industry as a whole.

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