Planning solar PV... maybe

Martyn1981

Pulpdiction wrote: »

@Martyn1981 - thanks, very useful, I guess if I put in a system of 4kw or just shy I could at some point, 3 or 4 years add to that (assuming I would need to get a slightly oversized inverter for day 1 - to cope with a later increase), would it only be at that point that my FIT rate would drop by 10% or would the whole thing be assessed against the FIT rate which applied at that time?

Thanks

T and I both did later extensions. That way the earlier system locks in its FiT rate, and only the extension gets the lower rate. But the 4-10kWp rate difference is now very small, only 10% (1.3p). I'd suspect the cost of going bigger in one go would balance out, you just need to get a price that is proportionately 10% less, eg £5k for 4kWp, or £5.6k for 5kWp.

There's a section on extensions, and info on going bigger in section 10 of the FAQs.

Mart.

Pulpdiction

EricMears wrote: »

Theoretically : Yes.

However, you'd need to supply the combi with water at or close to mains pressure so would either need a pressurised vessel as your 'header tank' or else install the header tank at least sixty feet above the boiler.

And another snag might be that if you were feeding your combi with very hot water (and unless it was a huge header tank, it would indeed get very hot) then your DHW supplies would be dangerously hot unless you put in a separate blending valve to mix combi output with cold water or perhaps used a thermostat to limit that tank temperature to 40 deg (and I don't think an immersion stat of that level is normally available ?).

Afraid there's every chance that doing all the above would make the project uneconomic !

So I guess I could put a header tank in to feed two showers directly - mixer showers, and the hot water for the bath, and leave everything else on the combi? Would that 'simplify' things?

Pulpdiction

So in summary my first quote is a 16 panel QCell system with a Sunny boy 4000TL inverter and a geo II monitor for £4,850 fitted. Any views on that?

They are recommending a split of 10 panels of the SE facing roof and 6 on the SW facing. Installed before 1st July, they will do all the paperwork with me on the day.

theboylard

Jumping ahead,
Decide who you are going to for your FiT (doesn't have to be your utility co) beforehand, get their electronic forms and get them done on the day, then email them off with scanned/photos of:
MCS Certificate (provided by installer),
Invoice clearly showing as paid (you have to prove ownership of the install in order to receive the FiT),
EPC (if they are doing this then ask if they can complete prior to install),
Completed FiT form (you can complete 90% before the day), and
Proof of ID (passport scan/photo or similar)

Let your installer know of your plans to complete on the day, as the MCS cert is the bit they have to do, and you need the cert no. on your FiT application!

Why the urgency?

The FiT only starts when the FiT provider has received the docs - if you post, you could lose all sorts, especially at this time of year.

Plus, it only takes a few minutes to complete the form.
I use Foxit reader, the typewriter function makes filling in pdf's a doddle, and you can securely "sign" docs with an image of your signature.

Just my experience...

Martyn1981

Pulpdiction wrote: »

So in summary my first quote is a 16 panel QCell system with a Sunny boy 4000TL inverter and a geo II monitor for £4,850 fitted. Any views on that?

They are recommending a split of 10 panels of the SE facing roof and 6 on the SW facing. Installed before 1st July, they will do all the paperwork with me on the day.

I'm not saying go for it, but if you feel comfortable with the company, then that's a very nice price especially with a SMA inverter.

Only problem, will the rooves cause shading for each other? If so then that shade will creep across the panels, and as mentioned earlier, you might be better off with a SolarEdge (SE) system to deal with this. The SE inverter will be a few hundred less than the SB4000TL so even after adding the power optimisers at ~£30 each, it shouldn't cost much more. But not all installers do SE installs.

The SB TL's have excellent shade management software to help deal with hard shading, like chimneys, but a creeping shadow that slowly covers (or uncovers) multiple panels, is probably more than the inverter is designed to deal with.

Mart.

Pulpdiction

Martyn, thanks for your advice, I discussed shading with him and his advice was that as the SE facing roof is a lot steeper than the SW facing roof - notice the V shape in the roof means the roof doesn't rally cast any shadow over the SE facing roof he seemed to think it was not worth worrying about. Their web site also gives quite a bit of difference in the price for the two as can be seen here:

http://www.tpsolar.co.uk/Solarpv.php

He also said that the panels on the SW facing roof would be mounted as high as possible to minimise any shading in the evening from the SE facing roof.

oldskoo1

That is a very good opening quote as Mart says, especially with a SMA inverter.

The suggestion of solar edge with optimisers is a good one.

As mentioned, do your homework on the company, look for reviews on forums, look for how long they have been operating and also look at their accounts.

Check when they were MCS credited and check they offer an insurance backed warranty on the install.

As for the installation. SE/SW installations are very effective. I have been told that SW is preferable if you have the option to choose where to put more panels, one reason being more energy is used later in the day in average.

I was quite sad and took pictures of my roof and shading through different times of the day. The installer used this information to choose a suitable positioning for maximum generation.

Also cross check it with http://suncalc.net/ which will help see what the sun does during other months.

I think you have a great starting quote, your ROI will be good at this starting point, just do your homework on the company and choose positing wisely. I am repeating myself now, but also consider the solar edge and optimisers if you have shade.

oldskoo1

Just had another look at your opening post, i think with a pitch of about 47 degrees SE you should do better than average either side of summer due to being SE and quite a steep angle for the lower sun months.

Can you fit 2kW on the SW roof too?

I would be very interested to see your generation if you go for it.

Pulpdiction

Thanks olskool1 - the split would be 10 panels on the SE facing roof and 6 on the SW. So with the optomisers you get one on each panel at circa £35 a go, what are the key benefits? Could I fit them retrospectively later?

Pulpdiction

Here is my sunclac for today if that helps: