Considering a Lot (100+) Solar Panels on a New Build. Have a Few Questions!

blobert

Hi Guys,

We're hoping to build a large (400m2+) bungalow that's going to have a large south facing roof on it, will look a bit like this:



The roof will be made out of sheet metal so it should be very simple to clip solar panels to the roof.

While I was planning to install a decent amount of panels anyway I'm also exploring the possibility of essentially covering the roof in them, in theory we could fit up to 150-200 of them on there. Panels are very cheap these days and I figured it might be easy to do install lots of them during the build process as opposed to putting some in now, maybe adding more later etc.

I'm interested in the principle of building a house that produces considerably more energy than it uses in a year. Now in reality this would mean we'd produce WAY more than we'd need in summer which we'd sell back to the grid (I believe they have a feed in tariff coming, even if it's only tiny) but we'd still need to use grid energy at night (till we get a battery system when prices get cheaper) and probably in winter also. But over the course of the year I think we'd generate much more than we'd use, including charging our electric car, if we had most of the room covered. The house would be all electrically powered ie no other fuel source and would incorporate lots of other green tech such as rainwater harvesting, ground source heating etc.

Now what I'm wondering is if there is any downside to having a huge amount of solar panels vs a normal install which I'm unaware of?

I'm thinking I'd need to have a bunch of inverters or one mega one, not sure if that's likely to complicate things/be much more expensive.

Also I'm wondering where these inverter/s would best be installed. At the moment there is going to be a plant room in the centre of the house. Would these go in there or would it make sense to put them in a room outside the house where we'd probably add battery storage later as I'm assuming it probably wouldn't be wise to have a ton of batteries inside the house?

Like I say I'm just trying to work out if there is any issue in going with a lot of solar vs a more typical sided installation.

Thanks in advance!

KCross

You’ll likely hit a roadblock with ESB allowing anything more than 6kWp being connected to the grid from a house.

The levels you are talking about are more commercial in nature so you’ll probably need a 3 phase connection and even then they might not like it. Have a chat with ESB and see what they say.

blobert

KCross wrote: »

You’ll likely hit a roadblock with ESB allowing anything more than 6kWp being connected to the grid from a house.

The levels you are talking about are more commercial in nature so you’ll probably need a 3 phase connection and even then they might not like it. Have a chat with ESB and see what they say.

Thanks for that. I see in the feed in EU tariffs paper they seem to have a 30kw limit so about 100 panels. But that might be different here.

Any idea what part of ESB would be good to contact as opposed to a call/email to general customer service who will probably be confused by the request?

Thinking 3 phase electricity might make more sense to futureproof the house for future more powerful electric car charging also.

KCross

I don’t have a contact for you.

Is the house rural? 3ph could cost many many thousands to connect as you have to pay for all the work as opposed to a set regulated fee for a standard connection. If the 3ph line is miles away it won’t be economical to do for a one off house. If it’s nearby it might work out.

What EU tariff paper are you referring to? A FiT is probably a few years away ( at least until Smart meters are rolled out).

KCross

Have you read this part of ESBs website
https://www.esbnetworks.ie/new-connections/generator-connections/connect-a-micro-generator

It says 11kW is the max for domestic scenarios with 3ph. More than that and you are considered commercial where the money side will probably go funny!

blobert

KCross wrote: »

I don’t have a contact for you.

Is the house rural? 3ph could cost many many thousands to connect as you have to pay for all the work as opposed to a set regulated fee for a standard connection. If the 3ph line is miles away it won’t be economical to do for a one off house. If it’s nearby it might work out.

What EU tariff paper are you referring to? A FiT is probably a few years away ( at least until Smart meters are rolled out).

Thanks,

House is in reasonably built up part of Dublin City so I'm assuming 3 phase would not be that complex.

As it's a new build I'd assume it would get a smart meter by default (assuming the are doing them now)

I found EU paper via thread here on FiT: https://eur-lex.europa.eu/legal-content/EN/TXT/HTML/?uri=CELEX:32018L2001&from=EN#d1e2850-82-1

I might be reading it wrong but it seems that 30kw is the cut off point:

"if the self-generated renewable electricity is produced in installations with a total installed electrical capacity of more than 30 kW."

I suppose it might be risky to pay to put up a load of panels in advance of knowing what the scheme, if any was.

Like I say I'm keen on the idea of building a house that will produce more energy than it needs but unless there is some sort of FiT scheme I'm guessing the reality is that I'd just be supplying ESB with a lot of free electricity if I scale it beyond what out house itself will use.

Any further advice on this would be appreciated.

Even if I were to keep it under 30kw would there be any considerations I should be aware of in terms of needing very powerful inverter etc?

KCross

Smart meter roll out is being done over the next 4yrs. You may not get one for a few years, depends on where you are.

The 30kW in EU docs won’t necessarily reflect back to ESB. They would currently class anything above 11kW (3ph) as commercial so they will likely make you jump through lots of additional hoops before allowing you to connect that up and force you to pay any network upgrade fees as well which could be silly money. e.g the transformer connected to your property and local infrastructure in general might not be suitable for taking what you are planning.

Being in Dublin City you might have reasonable access to 3ph but you need ESB to quote you. It may not be close by. A site survey and quote would be worthwhile.

You really need a conversation with the ESB first on Solar and 3ph before you look at anything else. There is a Solar generation email address in the link I gave so at least you’ll get someone that works in the area rather than general customer service.

FiT could also be years away and when it does arrive it could be small. Difficult to know if it would pay to put up what you are suggesting.

unkel

If you decide to go ahead with your full roof covered in PV panels, there are some companies out there who make solar roof tiles (like Tesla) or will do so in the near future. It's an option worth exploring if you're doing a new build.

thos

You could try chatting to this guy also - https://twitter.com/KevinSharpe59/status/1291463431153909760
He's done 16kwp in an effort to go off-grid

blobert

KCross wrote: »

Smart meter roll out is being done over the next 4yrs. You may not get one for a few years, depends on where you are.

The 30kW in EU docs won’t necessarily reflect back to ESB. They would currently class anything above 11kW (3ph) as commercial so they will likely make you jump through lots of additional hoops before allowing you to connect that up and force you to pay any network upgrade fees as well which could be silly money. e.g the transformer connected to your property and local infrastructure in general might not be suitable for taking what you are planning.

Being in Dublin City you might have reasonable access to 3ph but you need ESB to quote you. It may not be close by. A site survey and quote would be worthwhile.

You really need a conversation with the ESB first on Solar and 3ph before you look at anything else. There is a Solar generation email address in the link I gave so at least you’ll get someone that works in the area rather than general customer service.

FiT could also be years away and when it does arrive it could be small. Difficult to know if it would pay to put up what you are suggesting.

Thanks for that, I've tried emailing ESB, have yet to hear back, hopefully will soon.

blobert

thos wrote: »

You could try chatting to this guy also - https://twitter.com/KevinSharpe59/status/1291463431153909760
He's done 16kwp in an effort to go off-grid

Thanks, have tried to reach out to him also!

blobert

unkel wrote: »

If you decide to go ahead with your full roof covered in PV panels, there are some companies out there who make solar roof tiles (like Tesla) or will do so in the near future. It's an option worth exploring if you're doing a new build.

Thanks, I'm not that keen on a slate roof due to the style of the new house and I think the roof type we're using (sheet steel or aluminium) will be pretty cheap so I'm guessing the cost of that + cheap panels might be cheaper in any case.

That said if you have any examples of companies offering this in Europe I'd be happy to look into it, I think Tesla are not offering them yet?

blobert

Oh and one other thing. Is there a way I can calculate how much power a panel/group of them is likely to generate in the real world in Ireland at different times of year.

Ie if I have 30kW of panels on the roof, how much power could I hope to generate on a sunny/cloudy summers day, then in mid winter etc. Not sure if there's any online calculator to give me an estimate.

Gumbo

blobert wrote: »

Oh and one other thing. Is there a way I can calculate how much power a panel/group of them is likely to generate in the real world in Ireland at different times of year.

Ie if I have 30kW of panels on the roof, how much power could I hope to generate on a sunny/cloudy summers day, then in mid winter etc. Not sure if there's any online calculator to give me an estimate.

Real world figures

https://www.boards.ie/vbulletin/showthread.php?t=2058050685&page=

Coltrane

KCross wrote: »

You’ll likely hit a roadblock with ESB allowing anything more than 6kWp being connected to the grid from a house.

My understanding is that ESB will approve >6kWp arrays if the installing electrician certifies that export is limited by the inverter to 6kW.

This would allow OP to cover his roof and so generate decent power on darker days, but cap his FiT.

Coltrane

blobert wrote: »

I'm assuming it probably wouldn't be wise to have a ton of batteries inside the house?

Yes I think that’s correct.The fire-risk seems to me to be underestimated by many.

Another point to factor is wind: have a look at wind levels on your site and consider the lift that 200 panels would produce...

Coltrane

blobert wrote: »

Hi Guys,

We're hoping to build a large (400m2+) bungalow that's going to have a large south facing roof on it, will look a bit like this:



The roof will be made out of sheet metal so it should be very simple to clip solar panels to the roof.

While I was planning to install a decent amount of panels anyway I'm also exploring the possibility of essentially covering the roof in them, in theory we could fit up to 150-200 of them on there. Panels are very cheap these days and I figured it might be easy to do install lots of them during the build process as opposed to putting some in now, maybe adding more later etc.

I'm interested in the principle of building a house that produces considerably more energy than it uses in a year. Now in reality this would mean we'd produce WAY more than we'd need in summer which we'd sell back to the grid (I believe they have a feed in tariff coming, even if it's only tiny) but we'd still need to use grid energy at night (till we get a battery system when prices get cheaper) and probably in winter also. But over the course of the year I think we'd generate much more than we'd use, including charging our electric car, if we had most of the room covered. The house would be all electrically powered ie no other fuel source and would incorporate lots of other green tech such as rainwater harvesting, ground source heating etc.

Now what I'm wondering is if there is any downside to having a huge amount of solar panels vs a normal install which I'm unaware of?

I'm thinking I'd need to have a bunch of inverters or one mega one, not sure if that's likely to complicate things/be much more expensive.

Also I'm wondering where these inverter/s would best be installed. At the moment there is going to be a plant room in the centre of the house. Would these go in there or would it make sense to put them in a room outside the house where we'd probably add battery storage later as I'm assuming it probably wouldn't be wise to have a ton of batteries inside the house?

Like I say I'm just trying to work out if there is any issue in going with a lot of solar vs a more typical sided installation.

Thanks in advance!

Envy you the project! Plenty of potential here to do something really environmentally friendly. Have a look at this recent episode of Fully Charged: https://m.youtube.com/watch?v=sSE8PurhfQs

blobert

Coltrane wrote: »

My understanding is that ESB will approve >6kWp arrays if the installing electrician certifies that export is limited by the inverter to 6kW.

This would allow OP to cover his roof and so generate decent power on darker days, but cap his FiT.

Thanks, that could be promising, and better still if I went 3 Phase it could be 11kwh

Yes I think that’s correct.The fire-risk seems to me to be underestimated by many.

Another point to factor is wind: have a look at wind levels on your site and consider the lift that 200 panels would produce...

I am a bit worried by the wind risk, will have to look into it.

Envy you the project! Plenty of potential here to do something really environmentally friendly. Have a look at this recent episode of Fully Charged: https://m.youtube.com/watch?v=sSE8PurhfQs

Thanks, hoping to do a good job of it. I'd seen that video recently, house looks enormous!

KCross

Coltrane wrote: »

My understanding is that ESB will approve >6kWp arrays if the installing electrician certifies that export is limited by the inverter to 6kW.

This would allow OP to cover his roof and so generate decent power on darker days, but cap his FiT.

You can have more than 6kWp on your roof alright but whats the point in having 30kWp of panels and only able to use 6kWp of it?!

I understand that production will be low in winter and you might be lucky to even get 6kW from it in the winter but thats not much good if you actually have 30kW being generated in the summer and only 6kW being used.... it doesnt make sense really.

If you put up 30kWp you want to be able to use it yourself or send it to the grid.

Coltrane

KCross wrote: »

You can have more than 6kWp on your roof alright but whats the point in having 30kWp of panels and only able to use 6kWp of it?!

In my own case the point was to generate as much energy as poss from my roof, for environmental reasons. A large part of it is given to the grid for free during summer and that’s fine because return on investment was not my priority. On sunnier, summer days the inverter even caps the export at 6, and that’s ok too because I know that for the rest of the year the shutoff panels are contributing.

If ROI is more to the forefront for OP, you’re right, that spread between 30 and 6 is too large, even with an EV, battery and cylinder to soak up the surplus on brighter days. Particularly if his entire array will be south-facing.

But if he reduced his array size and mitigated with those capacitors and a mix of orientations he might be able to get the waste down to acceptable levels, given his wish to max out the roof.

blobert

Thanks again for the replies guys, I really appreciate them.

I think probably I'd want to be getting paid on some level for feeding a lot of electricity into the grid if I had a large solar setup on the roof, or if not, limit it so that it's practical, ie there is probably no point in having a 50kW system if I could only export 11kW max. Though it might be worth having somthing like a 20kW one if this meant I could generate a decent amount of power even through the winter and (at some points in summer) be producing a surplus to what our house uses/what I can export if there's a 11kW limit for 3 phase.

Does anyone know who in ESB I can contact about solar generation and/or seeing if a 3 phase connection is possible for the new house?

As per KCross's post I tried the email NetworkServicesBureau@esb.ie for microgeneration but got no reply after 2 mails.
I also tried DSOgenerators@esb.ie which I think is for larger/commercial installs but got no reply either.
Neither sections seem to have a phone number.

I'm guessing talking to ESB in advance of doing anything makes sense.

I saw this page and am not sure if it's relevant to what I'd like to do: https://www.esbnetworks.ie/new-connections/generator-connections/connect-a-renewable-embedded-generator

It talks about generators of > 11kW ≤ 50kW which is what I'd be, ie bigger than standard install but far from a wind farm etc but I don't know if this is relevant.

I'm guessing if I was setting up as a commercial electricity provider it might get a lot more complex but I'm not sure. Presumably if Ireland wants to meet their targets for renewable energy by 2030 they would be pleased to have individuals generating as much renewable power as possible? But I'm guessing ESBs network is not set up to work with this at the moment?

Any further advice would be much appreciated!

phester28

Wait for the Low usage charge. I think there is already something that if you use less than a certain amount of KWH then you need to pay more standard charge as you are considered a low user.

KCross

blobert wrote: »

Thanks again for the replies guys, I really appreciate them.

I think probably I'd want to be getting paid on some level for feeding a lot of electricity into the grid if I had a large solar setup on the roof, or if not, limit it so that it's practical, ie there is probably no point in having a 50kW system if I could only export 11kW max. Though it might be worth having somthing like a 20kW one if this meant I could generate a decent amount of power even through the winter and (at some points in summer) be producing a surplus to what our house uses/what I can export if there's a 11kW limit for 3 phase.

One other thing, after you talk to ESB, there is a theoretical limit to the number of panels you can connect to any given inverter. Doesnt matter for most people as they wouldnt be anywhere close to it but what you are considering might be a limiting factor for you.

So, lets say ESB say you can have 3ph and you can export 11kW and so you buy a 3ph 11kW inverter you may not be able to connect 50kWp of panels to that 11kW inverter. You can add more that 11kWP of panels but there is a technical limit to the number of panels you can connect to it.

As an example, and I'm not 100% sure of my figures so please let someone else here cross check it....

The 3ph 12kW Solis inverter here
https://static.solartricity.ie/wp-content/uploads/2020/06/Solis-10kw.pdf

... has an MPPT voltage range of 160-850V so the max each string can take is 850V. A typical 300W panel will be about 32V so that means each string can take about 25 panels and it can take two strings so 50 panels (not sure if you can actually add 850V to both strings, I think it might only take "Max input voltage" of 1000V?)

Thats a total of 16kWp. Still a long way short of your 30-50kWp suggestion.


Anyone care to comment on whether my understanding is correct there?

unkel

KCross wrote: »

Anyone care to comment on whether my understanding is correct there?

Your understanding is correct. Inverters have a maximum DC input voltage. And the issue with solar PV panels is that they supply (near) full voltage during the day, even though the amps might be near zero, so your output in watts is near zero

blobert

KCross wrote: »

One other thing, after you talk to ESB, there is a theoretical limit to the number of panels you can connect to any given inverter. Doesnt matter for most people as they wouldnt be anywhere close to it but what you are considering might be a limiting factor for you.

So, lets say ESB say you can have 3ph and you can export 11kW and so you buy a 3ph 11kW inverter you may not be able to connect 50kWp of panels to that 11kW inverter. You can add more that 11kWP of panels but there is a technical limit to the number of panels you can connect to it.

As an example, and I'm not 100% sure of my figures so please let someone else here cross check it....

The 3ph 12kW Solis inverter here
https://static.solartricity.ie/wp-content/uploads/2020/06/Solis-10kw.pdf

... has an MPPT voltage range of 160-850V so the max each string can take is 850V. A typical 300W panel will be about 32V so that means each string can take about 25 panels and it can take two strings so 50 panels (not sure if you can actually add 850V to both strings, I think it might only take "Max input voltage" of 1000V?)

Thats a total of 16kWp. Still a long way short of your 30-50kWp suggestion.


Anyone care to comment on whether my understanding is correct there?

Thanks, I would assume it's possible to get a more powerful inverter like this:

https://www.solar-bouwmarkt.nl/growatt-40000-tl3-s.html

Which might be able to handle 30+kWp?

blobert

Just as an update on this, after a bunch of prompting mails to ESB I got a reply quite short on detail to the questions I'd asked:

ESB Networks is committed to actively supporting all Irish homes, committees and businesses in their choices and activities in the energy sector. ESB Networks works to meet the needs of all Irish electricity customers, providing universal affordable access to the electricity system for our customers.



Any premises that is exporting electricity onto the distribution network needs to apply for a grid connection to ESB Networks in advance of the electricity being exported. The grid connection process will be dependent on the scale of electricity being exported. Details regarding the grid connection policy for connecting renewable generation can be found at our website (https://www.esbnetworks.ie/new-connections/generator-connections . The website should provide you with a better understanding of the grid connection process that is relevant for generation of varying sizes i.e. from microgeneration to larger scale generation.



ESB networks are responsible for the safe, secure and reliable operation of the distribution network. ESB Networks are not responsible for the establishment of any potential feed in tariff for electricity and so cannot provide any update in relation to this matter.

I've written back to them trying to get some further info but I'm not too optimistic.

From reading this article here my feeling is that they are not overly keen supporting this area: https://www.thejournal.ie/solving-solar-noteworthy-5185924-Aug2020/

One thing I was wondering is if you guys have any understanding of this part of their site:

https://www.esbnetworks.ie/new-connections/generator-connections/connect-a-renewable-embedded-generator

I believe this deals more with commercial plants, such as if someone had a wind farm/field full of solar.

That said it seems to be referring to power generation in the range I'm looking at (as opposed to massive plants), it talks about MIC and MEC Capacity Ranges > 11kW ≤ 50kW which would be what I'd be aiming for.

I'm afraid I don't really understand a lot of what this page is about.

If I were to apply via this as opposed to as an individual doing microgeneration would it be possible to produce up to 50kW of solar power (or more) and sell it to ESB?

Would there be any downsides to this? Ie, would I now be seen as a power plant as opposed to a residential house and have to meet commercial/other standards than if I were doing microgeneration?

I'm finding it tough to get an understanding of this so if anyone had a better knowledge of it I'd appreciate it.

The above article has a very brief mention of it:

Anything above 11kW and you need to fill in a more complicated form, pay an application fee of over €750, and grid connections are capped at 30 offers per year.

But it's still not clear to me how this would work.

Thanks again for all the replies!

KCross

blobert wrote: »

Would there be any downsides to this? Ie, would I now be seen as a power plant as opposed to a residential house and have to meet commercial/other standards than if I were doing microgeneration?

Thats basically the summary of it, yes.

Anything over the 11kW and you will have to jump through hoops.

unkel

Politburo says no

blobert

Hi Guys,

Just coming back on this as I got another reply from ESB.

They said:

ESB Networks, as the Distribution System Operator (DSO) in Ireland, is responsible for the safe, secure and reliable operation of the distribution system. Payment to generators of all sizes, from microgenerators to large scale generators, are a matter for the generator and an electricity supplier not ESB Networks. The extract below is from the governmental Climate Action Plan:



“The Government strongly supports enabling people to sell excess electricity they have produced back to the grid. To enable this, we will have to make a number of changes …• Change the electricity market rules in early 2020 in order to enable micro-generated electricity to be sold to the grid. This should include provision for a feed-in tariff for microgeneration to be set at least at the wholesale price point”



As per the Climate Action Plan, a support scheme will be introduced from June 2021 for microgeneration. We understand that the DCCAE are progressing this matter. ESB Networks seek to support this activity. ESB Networks are not responsible for establishing a support scheme. This is a matter for DCCAE as outlined in the Climate Action Plan.

For generation in the range of 11-50kW, a grid connection application is required to be filled in and sent to ESB Networks for assessment. ESB Networks connects generators to the network. The sale/purchase of electricity is to be agreed between the generator and the Supplier.As part of a customer’s grid connection application, a technical assessment is completed by ESB Networks which will inform the customer of any technical requirements before the installation can connect to the network. Commercial matters are a matter for the customer to review.

What I'm wondering with this is if I did put up 50Kw of panels and looked to be a small scale generator as opposed to micro generator, who would I be selling the power to?

Would the likes of an Energia/SSE Electricity or one of the other suppliers or would they only want to deal with huge wind farms?

I can find nothing on any company's websites about this other than Community Power who seem to potentially buy generated electricity as per their FAQ: https://communitypower.ie/frequently-asked-questions/

If anyone had any knowledge of this I'd appreciate it, seems very tricky to find out anything about it!

Finally just as a very basic question on this I'm assuming electricity is a mix of renewable/gas etc in the grid. Ie if I'm producing solar power and some renewable only provider pays me for it they are just buying this amount renewable energy, but in reality their customers and all customers receive the same mix of sources in the power to their homes?

Del2005

blobert wrote: »

Hi Guys,

Just coming back on this as I got another reply from ESB.

They said:



What I'm wondering with this is if I did put up 50Kw of panels and looked to be a small scale generator as opposed to micro generator, who would I be selling the power to?

Would the likes of an Energia/SSE Electricity or one of the other suppliers or would they only want to deal with huge wind farms?

I can find nothing on any company's websites about this other than Community Power who seem to potentially buy generated electricity as per their FAQ: https://communitypower.ie/frequently-asked-questions/

If anyone had any knowledge of this I'd appreciate it, seems very tricky to find out anything about it!

Finally just as a very basic question on this I'm assuming electricity is a mix of renewable/gas etc in the grid. Ie if I'm producing solar power and some renewable only provider pays me for it they are just buying this amount renewable energy, but in reality their customers and all customers receive the same mix of sources in the power to their homes?

I'd say you'd loose a lot of tax breaks if you turn your PPR into a commercial enterprise.

bobbyy gee

If it covers more than 50% of your roof you need planing permision
You can put thin film solar panels on metal roofs are you getting 250 watt panels or 350 watt panels you can probably only fit 37 panels on south facing part of your roof
Esb will not pay you for excess energy so you need 3 battery packs maybe 4 what are they. 4000 each

bobbyy gee

No power buy back

https://m.independent.ie/irish-news/news/esb-ends-scheme-for-homeowners-who-want-to-sell-power-30706655.html

graememk

bobbyy gee wrote: »

No power buy back

https://m.independent.ie/irish-news/news/esb-ends-scheme-for-homeowners-who-want-to-sell-power-30706655.html

That article is from 2014.

There is EU regulation (I think) that means that a new feed in tariff needs to be introduced by next year.

air

The pragmatic approach here in my opinion would be as follows:
Apply for a new connection with a 29kVA 3 phase supply (the current sweet spot for minimising standing charges).
Install a 3 x 100A rated main board to allow for a future capacity upgrade if ever required.
This gives you a decent supply capaciy with enough single phase current to avoid appliance issues.
Then install as much PV as you want but limit export to 11kW to keep within the domestic realm.

There are input voltage limits on inverters but in practice you can put multiple strings in parallel without isdue.
The maximum input current limit will clip the output on sunny days.
The ideal would be an 11kW 3ph inverter or a larger one with export limiting.
The latter would allow you utilise any excess above 11kW in your house when available.
Personally I wouldn't install more than 30kW of panels (~100) and would just wire them in parallel strings to a single inverter of 10-11kW capacity.
Simple, effective, relatively inexpensive & within the rules.

If an attractive FIT ever became available you could break out the strings & increase your inverter capacity to take advantage of it.
You might require an MIC upgrade at this point though.

A possible twist would be to request & install a 45kVA supply at the outset & immediately request a downgrade post connection.
This would give you the low standing charges & make an upgrade a paper exercise if ever required. Unfortunately there may be a charge for the downgrade due to your location, it's normally free.

I would consider an in roof panel mounting system. They are more expensive but this is offset by the saving on the cladding not used & the appearance is far more attractive IMHO.

Engage a competent electrical designer at the outset or you will be at the mercy of the contractor who is unlikely to be very experienced with much of the above.