Self Install Ground Mounted PV - Advice Needed

s2sap

Anyone any experience of this. I have read quite a bit about the installation process and it does not appear to be rocket science. OK I might need a spark to do the final wiring into the mains unit for grid connection, but I am thinking I could do the bulk of the work myself.

I have done some research and plan to use Enphase M215 micro inverters - they are basically "plug and go."

I am having difficulty sourcing them apart from through installers who naturally want to charge me their mark up, which is fair enough if they are installing but I hope to find a way to source them wholesale.

Also plan to use either Suntellite 250W poly PV panels or Sharp NDR 245W PV panels.

Anybody any advice or experience on this?

freddyuk

Firstly where are you planning to install this system? You have posted the same question in a UK forum and an Irish forum. Secondly as you are planning to connect the system to the grid; the country is critical as you will doubtless know? You will need prior permission in Ireland or you have 30 days to report to the DNO in UK for sub 4kw system.
Saying it is not rocket science is untrue. You can stick a few panels in the garden very easily. They may not be effective, safe or legal but it is possible.
As you are keen to do this on the cheap, spending money on solar equipment without a proper design plan may lead to an expensive system that does not perform and may lead to death or injury.
Once you have told us what the design plan is we can tell you if it will work.
As for doing it all yourself then asking a fully qualified "spark" to connect it up for you may be a long shot as a fully qualified "spark" will have spent several thousand £'s on training and certification and will not be happy to certify your back garden project without the benefit of the supply and installation to his own standard. It will be his reputation and insurance at stake. You cannot connect to the grid yourself in either country.
So good luck with the project but I would strongly suggest you have a rethink. Oh and don't forget the planning issues - depending on where in the world we are talking about.

s2sap

Firstly where are you planning to install this system? You have posted the same question in a UK forum and an Irish forum.

I live in Northern Ireland, and have posted on two boards to get as wide an opinion as possible as both jurisdictions have similar requirements. In actual fact Northern Ireland and mainland UK have also some differing rquirements. For some reason you seem to think it is strange to have posted in two different jurisdictions? I don't. The equipment is available in both countries and I am sure someone has installed a similar system in one of the two countries.

Secondly as you are planning to connect the system to the grid; the country is critical as you will doubtless know? You will need prior permission in Ireland or you have 30 days to report to the DNO in UK for sub 4kw system.


I understand that the regulatory requirements will have to be adhered to, and will do so.

Saying it is not rocket science is untrue. You can stick a few panels in the garden very easily. They may not be effective, safe or legal but it is possible.


I don't believe it is rocket science. I am lucky to have enough land available to site them in whatever array/ direction/tilt I need to. I probably won't just "stick them" somewhere, I might actually plan it quite carefully after much reading and research, this should make them both effective and safe. They will also be legal, as building control will be applied for and granted. In Northern Ireland I will not need Planning Permission.

As you are keen to do this on the cheap, spending money on solar equipment without a proper design plan may lead to an expensive system that does not perform and may lead to death or injury.

I am keen to do as much of the work myself as I can to save money, because again I don't believe the building of a frame to house the panels at ground level, orientating it to the correct direction and mounting panels to them is difficult. My understanding is that the panels will have a snap type electrical connector at their rear to continue the wiring along the loom back towards the consumer unit. I have already mentioned the two types of panel I am considering using and have thought of using Enphase M215 micro inverters - again my understanding is that they plug into the snap electrical connector at the back of the panel and come with their own wiring loom which is all snap connected apart from the mainconnection end obviously. This is where I was hoping to get some guidance from someone who knows this equipment.

Your comment As you are keen to do this on the cheap makes this plan sound sordid, unprofessional and that somehow trying to do some of the work myself to save money is immoral. Sorry if that is the case but thats what I plan to do and thats why I posted on a forum that is meant to allow sharing of ideas and to provide helpful advice to those seeking it. Oh and I hope to not have killed anyone in the process so far, unless I drop a panel on my head setting it on the mounting bracket!!

As for doing it all yourself then asking a fully qualified "spark" to connect it up for you may be a long shot as a fully qualified "spark" will have spent several thousand £'s on training and certification and will not be happy to certify your back garden project without the benefit of the supply and installation to his own standard. It will be his reputation and insurance at stake. You cannot connect to the grid yourself in either country.

The process I have discussed above does not in my opinion require a suitably qualified electrician, referred to in my post as a"spark" to save typing time. However I would not want to connect the system to the grid myself even if it was legal as I am aware of my abilities and am also aware of my limitations. This where I would seek a suitably qualified electrician to do the electrical connection to the grid. I am assuming I will be paying him to check / or connect the "plug and go" snap connectors at from each panel to each inverter, and then carry out the required work at the consumer unit to fit the required equipment to connect to the grid? Is that not what suitably qualified electricians do? You seem to think that as I don't want him to have the benefit of the supply and installation to his own standard up to this stage he shouldn't carry out this work. I am happy to pay a suitably qualified electrician to carry out the work required - I am not prepared to pay him for the preparation work - sorry if that doesn't sit well with you. I personall feel that a good electrician who is keen for work when offered X amount of hours work at his hourly rate will be happy to carry out the task I have described above, albeit that it is my "back garden project"

So good luck with the project but I would strongly suggest you have a rethink. Oh and don't forget the planning issues - depending on where in the world we are talking about.

Thank you for your good wishes. What part is it that you think I should rethink? Planning issues already discussed for this part of the world!

Once you have told us what the design plan is we can tell you if it will work.

What do you think Freddy, will it?

Let me now put some further meat on the bone that may just hang me, but here goes.

I posted a message looking for general ideas and thoughts on this forum and the reply I got was condascending, and I have replyed to it with hopefully tongue in cheek responses that will not offend anyone. I may not have given sufficient information for more experienced board members to reply, but I didn't know what further information was needed to start the discussion.

I have not read any more of the posts of my only respondant - Freddy - so I don't know if he is usually helpful to others looking for information, nor do I know why he was so negative with his response to me. Anyway I am keen for anyones help, guidance or otherwise in my search for information to carry out my project.

freddyuk

My response was not negative or condescending. Your post does not even start to explain what your plan is and without knowing the country you are talking about or the size of the planned install. I know NI is different to UK and ROI so if you had mentioned this it would have been helpful but the regulations are quite different and being "close" is not enough as this is a safety issue.
You have mentioned a couple of module makes and a micro inverter system.
Why are you looking at micro inverters? It seems to me you are doing this because it is "plug and play" ie. easy to do but until you have an overall plan you cannot just keep plugging modules together. Micro inverters are expensive and only used where shading is a problem unless money is no object - which clearly it is for you.
You would be well advised to read through the MCS documentation and certainly this:http://www.microgenerationcertification.org/about-us/news-and-events/102-new-pv-guide-released

Maybe you are fully clued up on DC electrics but I would not know that from your post so I would be warning you of the potential pitfalls. Connect a couple of 250wp modules together and you have a huge electrocution potential. A badly designed system will perform well below par thus ensuring your savings by DIY'ing are wasted on poor returns if indeed you can get an someone to certify your work and get a grid connection.
Including this sentence seems to be at odds with your comments above... Quote: "OK I might need a spark to do the final wiring into the mains unit for grid connection, but I am thinking I could do the bulk of the work myself." Unquote...
Am I supposed to guess that is not what you actually meant but in fact the electrician is going to do all the testing and wiring and you will just build a framework and hang some modules.

A quick check on the Ephase site suggests neither of your chosen modules are compatible. Unless you have checked with Enphase directly?

So I am sorry if you feel my advise was ill considered or unhelpful.

http://www.nie.co.uk/Connections/Generation-connections/Microgeneration

quentingargan

I would just bear in mind that there are pros and cons to micro-inverters. Pros particularly if there might be partial shading which happens more easily on ground mounted arrays. If you use micro-inverters, then you are connecting the grid from module to module, whereas if you use a regular single inverter for all modules, your cable voltage can be higher and you may be able to use a smaller cable size if the distance to the grid connection is long. The strings from module to module will be single wires instead of grid voltage as well so you can daisy chain the modules with no wiring at all for most of the connections.

I know someone who did a DIY module mounting for a 12kw system recently - he has written up a page for it, but not published it yet. If you PM me I can perhaps give you the temporary link. The grid connection was done by a spark. I agree with both posters in a sense that there is an irony in having solar PV training courses, but in the South of Ireland at least, the ESB only want a RECI or similar cert and don't give a hoot what happens upstream of the inverter.

s2sap

Freddy

Thank you for the links and the response, I do appreciate your input.

The micro inverters were being planned because there may be shading issues on down the line, not just because they are potentially plug and play, although I like that idea. I am aiming for maximum allowable single phase install - 6.5kw ground mounted now, but with the potential to be moved at a later stage. I am planning to build beside my existing home and move into the new property when completed, this may take 4-5 years. But I would like to proceed with the PV install now and start benefitting from them. When the design of the new house is available I will either have them roof mounted to it or they could be rewired to it from their currently proposed ground mounted siting.

I need some flexibility for the future, so with that and the potential for shading (depending on the exact orientation of the new build ) I felt that the micro inverters would prove long term more cost effective.

You are right to assume that I have little knowledge of DC electrics and would not even attempt any of the electrical work connections, however, I would certainly be capable of running the wiring etc from module site to the consumer unit, but would not be carrying out electrical work myself.

I have reread the Enphase data sheets and I see that they are suitable for connection to a 60 cell module and that the Suntellite panel is 72 cell module, is that why it is not compatible or is there something else? What should I be looking for?

I won't go into detail but the compatibility of the panels with the micro inverters was suggested to me by a supposed "specialist!!!" Unfortunately I have had bad experience to date with renewable energy installs having installed solar hot water and nearly having to pay half as much as the original install cost again to make it work. Naturall by this stage the company had gone bust and I had no comeback.


Quentin

I have sent PM for temporary link. So is it the case that a longer run ( which I will have initially anyway on the ground mounted array ) to the grid connection may be better served by a single inverter, or is it that with micro inverters I will have more wiring / expense.


I do appreciate any guidance anyone on this forum can provide and I do appreciate the time it takes to post a reply. I am perhaps not giving all the right information as I am unsure what is critical and what is generic to each install.

quentingargan

In relation to matching up the inverters, you need to check the open circuit voltage (Voc) of the module - then bear in mind that at lower temperatures than the rated 25C, the Voc will rise by a coefficient (also on the data sheet) calculated for the lowest possible temperature in your area.

Also check short circuit current (Isc) and make sure it is within the current limitation. But in your case I would think it is Voc that is the problem. (I haven't looked at spec sheets for modules or inverter, but Freddie knows his stuff on that and I assume has this done).

For a 6.5kw unit at 240V, the current in the wires will be 27A and over long cable runs this requires larger cabling, whereas you might be able to transmit this at 500V DC by putting modules in strings in series. For the same losses, the cable size at 240V is more than four times the cable size needed at 500V. But if partial shading is an issue, micro-inverters are very handy and optimise each module.