solar pv quote

tunnel

He is wrong about the shading(any chance of photos?), it only takes one panel to go into partial shade to bring the rest of the string down, believe me i have experience of it and have therefore retro fitted solaredge with power optimisers to one of my systems and it makes a big difference.

If you went to 4.2kWp then you would only be eligible for the next rate which is currently 13.5p, best to stick to 4kWp if you can and get 14.9

tunnel

Martyn1981

asturdy2 wrote: »

we are in burnley, 130 degrees is the compass measurement i.e 50 degrees from south, my quick measurements of the roof from ground level is 7.5m by 5m. Pitch on the quote is down as 30 degrees. Got 2 more installers coming today, if we could get 14 lg 300 panels on making 4.2kw would that be ok as we are not dead on due south and would not generate that much. We also have a metal chimney on the south side of the house which would give some shading early morning especially this time of year, he thought it wasn't worth mitigating it with micro inverters.

Sorry to be pedantic about the orientation, but 130 degrees compass, is SE not SW. This might be important if you have shading from a south chimney. Also a southern chimney, should affect generation around midday, regardless of SE or SW array (not morning), and depending on its affect, could spoil generation during (or close to) peak output. Perhaps the chimney is on the south side of the house, but further back, to the east of a SW roof(?) I'm starting to confuse myself now.

When you say 'you won't generate that much', actually SE or SW isn't bad at all, should only be about 10% off a south facing, but do check how much affect the chimney has. Have a look now, when you get a sunny day, to get an idea of how far any shadows travel across the roof, especially 10am to 2pm (GMT) when the sun is highest.

Mart.

asturdy2

heres the pic of the roof about 9.30am, second guy just been, says we could get 2 rows of 7 panels leaving a 25cm gap, going to quote for micro inverters aswell but says we could put 4 panels on 1 string near chimney and rest on another so we can compare quotes. He is going to quote for 12 327w sunpower panels but says they are expensive.

asturdy2

just had another quote, again stated mcs guidelines of 50 cm's and wouldn't go over this. so 12 panels again but with suntech power optimisers, 250w panels for a 3kw system £7.5K, or sunpower 327 panels 8.5K. He did say the shading would be an issue but they are too expensive.

tunnel

Did the last guy measure the roof? If its 7.5m x 5m as you think you could have them in landscape 4 x 4 and leave your desired 50cm around the edges. As i stated panels are roughly 1.6 x 1m
That way you can have 250W panels(which are cheaper) and probably couple it with a solaredge. Why have one small string, the shading will affect several over the day, with the solaredge only the ones with shade on them will underperform.

Plus point with the solaredge is the online monitoring so you can tell if any of the panels have malfunctioned and also see how the shading is affecting your generation. I have no experience with micro inverters so can't really comment.

tunnel

asturdy2

that was my rough estimate of the roof its more like 4.5 metres high, what about the picture do I need a solaredge ?

tunnel

I'm not an expert but that looks enough to bring a panel or two down and not just in winter.

There's been so many people come on here with stories of shading i'd personnaly just opt for them from the offset.

Solaredge inverter would normally have a 10 year warranty and the optimisers 25 year, but take into consideration that if one was to go then you'd need scaffold to go up and replace(same with micro inverter)

Could you not lower the pipe?

Martyn1981

asturdy2 wrote: »

that was my rough estimate of the roof its more like 4.5 metres high, what about the picture do I need a solaredge ?

Handy photo, but not good news I fear. Really need some advice from a good installer. We used to have a nice guy on here, but not around lately.

I suspect that pipe is going to cause problems. If the shade is large enough to cover a whole row/column of cells, then it'll knock the generation of the panel(s), and then the affected panel(s) will drag down the whole string.

Assuming roof is 230degrees, the chimney is to the SE, so could cause shading till the sun is higher (in the summer months), till around 10/11am. Not ideal.

Is it a boiler vent, that could be shortened/altered, or is it an actual chimney, that possibly needs to clear the ridgeline?

At the least you'll probably need separate strings to minimise the 'damage', ideally a twin MPPT inverter with the RHS panels separate to the LHS. But better still, if the pipe can't be changed, perhaps a SolarEdge system like Tunnel suggests. Good monitoring, and warranties, actually 12yrs I think.

Dimensions are tricky, I think T's 4x4 works well if the roof is 5m high, with 4m useable. But if a little smaller, then there are higher Wp panels that are still reasonably priced, such as YingLi 270Wp or more. Oh, may be another option, back in a bit.

Mart.

Martyn1981

Martyn1981 wrote: »

Oh, may be another option, back in a bit.

Damn, gone full circle and ended up back at those 300Wp LG panels in your first post.

What I was actually looking for, is some 2m by 1m panels, which could fit portrait 6 by 2, but cover a bit more roofspace. I'm sure there are a few, but coming up blank at the moment.

In fact, given that the Aurora Power One 3.6 inverter is dual MPPT (I think), then the original quote from post #1 is looking pretty good.

Mart.

asturdy2

Martyn1981 wrote: »

Damn, gone full circle and ended up back at those 300Wp LG panels in your first post.

What I was actually looking for, is some 2m by 1m panels, which could fit portrait 6 by 2, but cover a bit more roofspace. I'm sure there are a few, but coming up blank at the moment.

In fact, given that the Aurora Power One 3.6 inverter is dual MPPT (I think), then the original quote from post #1 is looking pretty good.

Mart.

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yes that was what I was thinking, installer said you need a minimum of 4 panels on a string so 4 on the right on 1 string and 8 on the left on the other, ive asked for a quote with micro-inverters but will ask about solar-edge aswell. Anybody got a link to more info on solar edge ?