Solar Panel quote, please help.. I'm (easily)confused

EricMears

CLVI wrote: »

That's sounds very promising Martyn, thank so much.

Is there any way I can post pictures of our roof from my iPhone on here? We have a south facing garden room with a solid roof that we could easily fit a couple of panels on around the velux, although the pitch is shallower.

Smaller panels sounds good, if we can fit them around our velux windows.

Our roof is steep, we had our loft converted a few years back and the headroom is good inside.

I'm a barber and a good number of my clients have had panels fitted here in North Norfolk and get good returns, but strangely none of them recommended I use their installers..

Thank you

Chris

AFAIK, the only way you can post pictures in this forum is to post them on another webpage and then include a link here to the url of your photo. Afraid MSE stop new members from posting url links or sending PMs to other members - but that restriction will be removed as soon as you've made a small number of postings (I think it's about ten but may have been amended since it affected me).

Martyn1981

CLVI wrote: »

That's sounds very promising Martyn, thank so much.

Is there any way I can post pictures of our roof from my iPhone on here? We have a south facing garden room with a solid roof that we could easily fit a couple of panels on around the velux, although the pitch is shallower.

Smaller panels sounds good, if we can fit them around our velux windows.

Our roof is steep, we had our loft converted a few years back and the headroom is good inside.

I'm a barber and a good number of my clients have had panels fitted here in North Norfolk and get good returns, but strangely none of them recommended I use their installers..

Thank you

Chris

Hiya Chris. I've been randomly sticking PVGIS pins in Norfolk again. It's not a bad place to have PV, that's for certain. But near the coast is very good. So much for having to live in Cornwall if you want PV!

Steep north roof will be a killer, unfortunately. Steep south is fine, almost better, as annual generation won't be affected too much, but you will see a small shift from summer to winter, which is good - less high generation export in the summer, and more useable generation in the winter. But a steep north roof causes a huge drop off, as it relies more on light being reflected down onto it.

Panel sizes, have a nose around and see what's on that site I linked to. But it's really down to what panels your prospective installers can get. For my upper roof the co-incidence of those 1.3m by 1m panels was uncanny, they were a perfect fit all round, top to bottom, side to side, and under the Velux. Very lucky.

Smaller rooves, I think Eric is right, to prevent naughty people and spammers, you are heavily restricted at first. You could post a link, but 'break it' with spaces, whilst explaining how to fix it, but that may be taken as a rule break, so maybe not.

If you want to PM me a dropbox photo link, or something similar, I'll be happy to post it, but again, as Eric said, PM's are restricted. I think you may be allowed one per hour, not sure?

Additional rooves - I'll do a separate post.

Mart.

Martyn1981

CLVI wrote: »

We have a south facing garden room with a solid roof that we could easily fit a couple of panels on around the velux, although the pitch is shallower.

Not a problem. Well ..... some problems, but easily solved.

The issue is, if the panels have too big a pitch difference, and are on a single MPPT (multi power point tracker) then the tracker will keep trying to find the common output, and thereby restrict the system to the lowest common denominator. That means the poorer performing panels will keep dragging down the rest.

Also, you'll need all panels to match, you can't have different outputs on the same string. Going back to my last post, you may want to use different size/make/output panels to get the best fit on the roofs, particularly around Velux'.

My ESE systems are separate as the upper system is on a steeper roof, and uses different output panels to the lower roof (13 * 185Wp v's 5 * 235Wp). At the time both the installer and I couldn't find a single inverter that could cope with all the differences, but I have since.

So, you have at least 3 options if you want to use the lower roof too:

1. Two separate inverters, one for each roof.

2. A dual MPPT inverter, that uses one MPPT for each roof, effectively treating them as separate arrays, but processing them through one inverter, saving costs. The only issue is if the smaller system is too small, as it will have to reach the minimum voltage (on each string) for the inverter. 5 panels will work, but I'm sure some inverters have low minimums that 4 or even 3 panels may reach.

3. A system that runs each panel independently so it doesn't 'care' if panels are different orientations, pitches, outputs etc. This might be micro-inverters (one on each panel) or power optimisers (one on each panel) running to a single inverter.

None of these options is actually difficult nor unusual. So take another look at the lower roof, and have a thunk about how many panels might fit to see if it's worth considering.

One last point - my lower system of 5 panels - only 3 of them are actually on the roof. Before the install I removed an old canopy (3.5m by 0.8m) which was over the back door, and had new galvanised brackets made up, to which two panels were fitted, giving me a new canopy (3.2m by 1m).

Lots of solutions once pondering begins! :think:

Mart.

CLVI

Thank you Martyn, if its ok with you I'll drop box you a couple of photos of our roof(s) and see what you think? I'm at work all day tomorrow.

I'd really like to get a company to do the whole shooting match, I m right in assuming that there is no stand out installer?