Feed in Tariffs - Utility Recommendation 11 November 2010 at 10:33AM in Green & ethical MoneySaving 23 replies 5K views

daytona600_2

all small inverters are lower effciency

3kwp and above offer higher effciencies 95/96%
bigger 10kwp units to 98%

why did he fit two inverters - one per roof
best option inverter with twin mppt trackers for split roofs
basically two inverters in the one box
ideal if one roof is shaded , as roofs are separted in the inverter
transformless for higher outputs and works out cheaper
than fitting and supplying two inverters

eg sma SB4000TL-20 96%
power one PVI-3.0-OUTD 96%
steca SG2000 + slave
and others

you could also add extra panels in the future
phono ps240 cheap asian units
you would get much higher FITs with higher effciency modules eg sanyo 240wp kyocera solarworld
and as these are smaller , so more panels in the same m2

gjpountain wrote: »

Thanks for your post have found it very interesting especially the point about the use of smaller inverters - see below.
The bit about the effect of shading on an overcast day is not clear -see below. Would be grateful for your further comments.

The strange thing is of course on a very cloudy overcast wet day
there is no discernable shadow so don't think shading is a problem on such a day.
By the way these are the bad days (since 29/10/2010)
2/11/2010 = 200 watts
4/11/2010 = 100 watts
8/11/2010 = 300 watts

Best Days
30/10/2010 = 5,100 watts
01/11/2010 = 4,800 watts
6/11/2010 = 4,900 watts
15/11/2010 = 4,400 watts
Be interested if you and others had the same good and bad days and was the difference as great between the worst and the best

Before installation during September I took many photos of the roof to see the effect of shading on roof 1 (South East facing). However whilst I am sure that during the summer months I have arranged the panels so that no panel is overshadowed after about 9am the sun has sunk so low in November (and will get worse until 21st December) that one of the panels is partly shadowed until about 1pm.
The other roof (6 panels south west facing) has a problem with a tree from next door. ( this did not seem a problem in September when the sun was higher. On a sunny day the leaves from this tree shade some of the panels for about an hour (around midday) and have noticed that the out-put from the panels halves during this time (from say 600watts per hour to 300watts per hour), This has no effect on an overcast day. The good news is that I have spoken to my neighbours and they are happy for me to chop down the last 15' of this tree (it may take a couple of years to grow back!). I have four trees in my garden which affect the panels from about 2pm - these I will have cut back this week as they have now lost their leaves. ( by the way I have about 14 trees in my garden some of which have preservation orders so these I can not touch). Much as I like trees they do grow very quickly and can shade everything and nothing grows beneath - not even grass.

The other point you mention is the inverters. I have 2 sunny boy sma 1200 inverters and questioned that I thought they should be sunny boy 1700 inverters. However I was given access to the free downloadable saftware:
http://www.sma-america.com/en_US/products/software/sunny-design.html
This showed that for 6 phono-solar panels 240watt the sma 1200 was more efficient than the sma 1700. So from the inverters their max outpout is 1200watts each - and they are only 92% efficient.
Graham

mulerider

Gizmosmum wrote: »

Tried Good Energy - you have to have your electricity with them:(, tried EDF who I have got electricity with and wont be moving before March but if and when I do move I have to move my FiT payment too . Trying Ecotricity now they seem to have a lot fewer strings attached.

I have emailed all the required documents to Microtricity (Ecotricity) today. We had a 2.25kW system commissioned last Wednesday and it has already produced 27kW. We live in a ground floor apartment and could only fit 9 panels on the roof.

You can contact Jodie Humphries direct:

01453 761391 or email her at [EMAIL="microtricity@ecotricity.co.uk"][email protected][/EMAIL]

I called to check she had received the application.

Scott

mulerider

You have to be a Ecotricity customer to register for the feed in tariff so I'm now registering our solar pv system with E.on. You need to provide a copy of the MCS certificate, photo ID and the system invoice with the E.on FIT application. You can call the FIT team on 01234 733 029.

http://www.eonenergy.com/At-Home/Products/Feed-in+Tariffs/