Considering solar via the green deal

siskyline

Hello all,

I am in the early stages of looking to get solar. So im interested in if it is viable and super keen on getting either a PHEV or a full EV to run on pure solar .

The main thing I know at this stage is that I would have to get a east/west split due to the orientation of my house. I should hopefully measure the pitch tonight if I can get in the loft. The ikea roof calculator thinks that one full side of the roof is 25m squared. Giving a maximum of 50m squared.

My question is if anyone has any experience with the relaunch of the green deal? I was unsure if solar was covered under it now.

Does anyone have a recommended installers in the sheffield area to get quotes off?

I also have a extension on my house where the roof almost faces south, would it be possible to place a panel or two on there giving me a east/south/west setup?

I've included a picture of Google maps for anyone interested.


House https://imgur.com/a/NQzDa


Thanks for any help.

Martyn1981

Hiya, have a read of the FAQ's (see my autosig), to get an idea.

Nothing wrong with E/W, but it will mean about 80% of the generation v's due south. However, it also means that you can install twice as much which should mean about 80% of the cost (per kWp installed) by going bigger - a lot of costs are fixed, so the bigger you go, the less the cost per kWp installed.

If you are seriously thinking of a PHEV or BEV in the future then future proofing by going as large as possible makes sense.

Looking at the pic, do you mean the small ext. If so then yes, but your options are reduced as you'll have panels facing 3 directions, so a dual MPPT inverter (treating two orientations separately) won't be enough. That means going for micro inverters (one per panel, or per pair of panels) or a SolarEdge system that maximises each individual panel.

Have a read, a think, then come back with loads of questions. There's an installer in Leeds with a good reputation, and one in Matlock that upgraded my 'old' ESE system to SolarEdge last summer. But again, best for you to chat and research first.

All the best.

siskyline

Hi Martyn,

Thanks for you speedy reply it's really appreciated.

Yes it is the small extension to the left of the picture that extends into the back garden. That is really useful information about the inverters as I thought you would just plug all the panels into one piece of kit

Yes a EV is something I'm saving for but given the large outlay for a high range model (I do a 120mile one way trip to my mum's once a month) it might be unobtainable. I do currently have my eye on the iconiq PHEV. It's battery range is good enough to get me to work and toot around town. I can then switch to petrol when going back home. But that is at least 18 months away untill my current PCP deal is up.

EricMears

I've sent you a PM with details of the installer we used. That was 6+ years ago but they're still in business (which is fairly unusual in this field ).

Based in Chesterfield but work all over the place so 15 miles or so is well inside their area.


Their website has recently been updated and looks pretty useless at the moment so I hesitate to publish the url here !

Martyn1981

siskyline wrote: »

Hi Martyn,

Thanks for you speedy reply it's really appreciated.

Yes it is the small extension to the left of the picture that extends into the back garden. That is really useful information about the inverters as I thought you would just plug all the panels into one piece of kit

Yes a EV is something I'm saving for but given the large outlay for a high range model (I do a 120mile one way trip to my mum's once a month) it might be unobtainable. I do currently have my eye on the iconiq PHEV. It's battery range is good enough to get me to work and toot around town. I can then switch to petrol when going back home. But that is at least 18 months away untill my current PCP deal is up.

My pleasure.

I've been pondering an EV recently (recently pondering that is). I worked out that even if the car isn't home, if I have about 10-15kWh of home battery, then I could run the EV off spare PV generation for the best 6 months of the year. We average about 7k miles pa.

But ...... be warned, whilst E, W & E/W are roughly 80% of south facing, it's not spread evenly. In the summer, you almost match south facing, so the 20% losses are crammed into the bottom 6 months, with Dec & Jan particularly poor.

Hopefully batts will be viable in a few years, but I'm sure the issue will pop up on this thread soon enough.

siskyline

Hey guys,

Sorry a bit of a long update.

So I've been able to get in my loft and got some mesurments. Thankfully my GCSE maths was not a complete waste and had fun doing some calculations haha.

The front length of the house is 720 cm
Using the Drop (210cm) and the run (340cm) in the loft ive calculated using trigonometry the roof angle is 30 degrees. Using pythagoras theorem with the same numbers I've got the width(? The top to the bottom of the roof) Of the roof at 400cm.

The roof faces are front 70 and rear 100 degrees off South

I understand that not all this space is useable because of my bedroom window and my extension cut into the surface of the roof.

I did get one quote put together over the phone and another company called me to arrange a visit on Wednesday (I was matched via this greenmatch co uk website. It seems other places I enquired where negative or denied a east/west split would work because it's not south :?


The phone quote recommended this layout for a 4kwp system

Panel layout https://imgur.com/a/k1sh9

And also offered two quotes. One with optimizers and one with out. They have selected the same panels for both.

16 Perlight 250W Delta Mono Triple Black
Solis 3.6kW 4G Dual MPPT Mini
5,284.00


16 Perlight 250W Delta Mono Triple Black
Solaredge 3680 HD Wave + Optimisers
5,995.00

With a projected return in 11/12 years.

My first thought is that the optimizers would be a good option, the reading that I've had on the suggests that it will get the max out of each panel and will help with shading.

What are people's thoughts on the brand of Panel? I've not heard of them during my research.

They also quoted an iboost for an extra 325 but looking at it vs the immersun I think I'm leaning towards the immersun however I don't know what the cost of it is.

I was also wondering if it is worth getting a larger system? I'm sure a panel or two will fit on my extension and points close to South, so would increase the overall preformace of the system. I know that I would need support from my DNO (northern power grid) for this. Would they likely allow bigger systems?
Is this also something that I have to apply for or find out likely it would be accepted before dreaming of a larger system?

When going above 4kwp is there a point of diminishing returns from an investment point of view?

Martyn1981

Hiya, not stalking you, just happened to log on at 4.30pm.

First thoughts, are that you should be able to install approx 12 panels on each roof in a 6x2 portrait layout, so approx 3.2m tall, and 6m long. This will allow for 300mm gaps all round and 20mm gaps between panels.

Looking at the image you may have to miss out 1 or 2 panels on the east roof, and 2 or 3 panels on the west roof. So perhaps 19 panels, and potentially 4.75kWp (250Wp panels) to say 5.5kWp (290Wp panels).

If you decide to go as big as possible, you can ask the DNO for permission to export more than 3.68kW, but, and this is important, the DNO doesn't have an issue with the amount of panels you install, so don't care about the kWp of the system, they only care about the kW's that the inverter can put out, even if only theoretical.

So you could install 5.5kWp in E/W format, running through a 3.68kW capped inverter, and not need any permission from the DNO.

For an E/W install of 5 to 5.5kWp, you will very rarely generate more than 3.68kW at any one time as the panels will peak at different times. Max kW's will probably be at midday in the summer, when the southern sun can 'see' all of your panels.

To 'SolarEdge' or not is a tricky question, but if you are going E/W, have some shading (?) then it might be a good idea, also the SE HD inverters are tiny, very efficient, and can cope with a massive amount of PV - their 3.68kW inverter can cope with 5.7kW of DC generation, not that an E/W setup would hit that, here's the datasheet.

SE inverters come with a 12yr warranty and can be upgraded to 20yrs cheaply (around £100 or so I think), but expect the installer to up it to 20yrs anyway.

Because so many costs are fixed, and scaffolding both rooves (if necessary) should only be a small increase, it's probably worth maxing out the PV to bring down the £'s/kWp cost, this will help to make up for the lower performance of an E/W system v's S facing system, since you get to use two rooves instead of one.

jimjames

Personally I'd be very wary of using the Green deal to fund it, you may find issues later if you want to sell the house so it might be better to buy outright even if you need to fund it separately

siskyline

Hey Martyn. Thanks a lot and I didn't notice you stalking, I had a fairly long drive comming back from mum's last night so wasn't browsing the forum

Thank you for the feedback. I will speak to them about add more or moving the configuration, they are suppose to ring me back to discuss their design in more detail at some point.

In their documents they also provided a SAP900 calculation for my generation and return. Is this worth following or should I attempt to calculate my own?

Thanks jim, I have noticed that the interest rate on the relaunch is quite poor so might pay some cash and small loan to cover it.

Regards,
Simon

Martyn1981

siskyline wrote: »

In their documents they also provided a SAP900 calculation for my generation and return. Is this worth following or should I attempt to calculate my own?

Regards,
Simon

Back when I got PV (and Cardiff was all fields ... ) the SAP's were rubbish as they were based on Sheffield, for the whole country, no seriously.

I think they are more local now, so certainly worth taking into account.

PV'ers seem to universally accept PVGIS as being very accurate. If anything it may set the default system losses a bit high at 14%, especially given the high efficiency of the SolarEdge HD wave inverters, but I believe in being a bit pessimistic and then enjoying the bonus, if there is one.

There's a walkthrough of using PVGIS in section 5 of the FAQ's. For you I'd suggest doing two, one east, and one west, then adding the results together.

So E will be, perhaps, 10 panels, so 2.5kWp, to 2.9kWp, at -70 (from south), and W will be, perhaps, 9 panels, so 2.25kWp to 2.61kWp, at +100*(from south).

*Just to say, if the East roof is -70d, then logically the West roof is probably +110d not +100d. Apologies for pedantry.

PVGIS is really simple, you'll get your head around it in mins.

siskyline

Hi Martyn,

Thanks once again for the information. You are really a fountain of it .

The sap calculation might not be too bad for me as I live about 6 miles out of the centre of sheffield how ever I will give the one you mentioned a go. I have been wanting to do my own calculations rather then relaying on seller and sales people to do it for me.

Yes I see what you mean with the angles, whoops. I just copied and pasted the information that one of the company's gave me

I did find someone with almost the same roof orientation by accident on Google maps and have slotted a letter in their box so I'm hoping they get back to me.

I've also got another quote that I will stick up shortly, but it seems a tad expensive compared to the one I posted. The only difference I can see is the panel brand and they have offered one less panel in the setup lol