Solar for Dummies.

unkel

https://www.boards.ie/discussion/comment/120126981#Comment_120126981

None

idc

https://www.boards.ie/discussion/comment/120126981#Comment_120126981

You can't get a window/door grant on its own but if getting upgrades via one stop shop then you can.

Energy Efficient Homes - Home Energy Upgrades And Grants | SEAI (table down the bottom)

or detailed one stop show info One Stop Shop Services | Home Energy Grants | SEAI

yankinlk

https://www.boards.ie/discussion/comment/120127789#Comment_120127789

This is true but is it an easy process? Had a friend give up on it recently.

It's a pity because imho after insulation it's the next best long term energy saver. Not cheap tho

micks_address

https://www.boards.ie/discussion/comment/120127946#Comment_120127946

I have double glazing already and pvc doors etc but they are probably 20 years plus old.. we replaced most of the glass in last ten years due to condensation between panes.. has to be done at some stage but longer term project

simpsimp

https://www.boards.ie/discussion/comment/120125747#Comment_120125747

Payment came within one week of approval.

kabakuyu

https://www.boards.ie/discussion/comment/120126981#Comment_120126981

Theres a scheme for the over 65's but it is on a case by case basis.

https://www.seai.ie/grants/home-energy-grants/fully-funded-upgrades-for-eligible-homes/

DC999

https://www.boards.ie/discussion/comment/120128861#Comment_120128861

My folks are applying for that now. They are in their mid to late 70s. Gaff is a modest 3 bed semi d. 1970s build with no wall insulation – norm at the time of course. Heat just leaves the gaff and is way colder than our own older but smaller house.

Personally, I think it’s a great scheme. They paid tax all their working life so should be entitled to not have to panic about how to pay to heat a house when on a low pension. Ok, I’ve a bias 😊 At the moment they have the heating off most of the time (due to the worry of cost) and are using coal for the sitting room. That’s the only properly warm room in the house. And of course coal fires aren’t good for anyone.

If house is sold in 5 years you’ve to pay some or all back afaik. Which is only fair of course.

Folks got the fuel allowance recently, which is one of the criteria for being eligible it seems. 

kabakuyu

https://www.boards.ie/discussion/comment/120128976#Comment_120128976

Are they getting other works done as well? and do they have to use just one contractor?

DC999

https://www.boards.ie/discussion/comment/120129219#Comment_120129219

No idea yet. Application only submitted

banie01

https://www.boards.ie/discussion/comment/120124966#Comment_120124966

Folks,

A question for those savvier than me regarding solar.

The sunpath photo shows the aspect of my house and due to chimney placement I can only get 9 on the front.

Now some have suggested putting 10 on the NW side and that the summer gains in particular will make that worthwhile.

If you look at the photo there is an outbuilding in the back that is handily outline in white. This building has a south facing pitched roof, 7.75mtr X 2.5mtr to apex (@ 19mtrs²). It has a consumer unit and internet connection tied back into the house electrics via 10mm² cables.

Would it be more worthwhile to put 7/8 panels there rather than 10 north facing? And would the installed 10mm² be sufficient? My plan would be to have inverter and any storage in the attic and power supply to shed crosses this( handy for installers?).

Appreciate any info or insight.

Manion

Hi

You could definitely get 8-9 panels given those measurements. You're 10mm2 wiring isn't super relevant as your panels are producing DC and will need to be connected directly to an inverter. So new cables would be needed to run back to the house and obviously there would be associate costs of those ground works. You could also go the second inverter (or micro inverters) route on the second array on the shed and connect the shed panels to the sub consumer unit in the shed. Might be the cheapest solution and you wouldn't need a Hybrid for the second. A couple people here have two inverter setups. Weather it's worth it depends on the price point.

For the sake of argument, lets say you can get 8 on the shed versus 11 on the NNW of the roof. The 11 panels are equivalent to 5.5 south facing, so you're gaining 2.5 panels or another way, about 1KWp capacity. Also lets say it's going to cost 3-4 grand for that extra 1KWp capacity which you're probably going to be exporting to the grid most of the time. You're either going to need ground works or another inverter.

Using the Europa site and setting a payback period of 7 years (Lifetime) that 1KWp is costing you over 50Cent a unit generated under ideal circumstances. You'd be better just importing.

If the choice is South+NNW or South main house + South shed, then the winner is to have everything on the main house.

Of course this would also leave you open to down the road adding an inverter in the shed and generating much more than the current limit.

DC999

https://www.boards.ie/discussion/comment/120130622#Comment_120130622

Yes, do all ahead of North.

Fill S first (as will give highest output, though on a low shed there could be some shading that the main roof won’t get). Then E (for morning) + W (evening). Only when all else is full would you look at N. I used a flat roof to get more panels on.

I’ve NW and it hibernates for winter. Output is grand to end Sept but actually stays iced over in this weather. Sun won’t get near it. @Manion has a North roof and fair play to him for doing it. That was the only direction he had available.

Manion

I don't think that's right to be so absolute about it tbh, it assumes costs are the same for both scenarios when in truth installing across two locations is likely to introduce additional costs and the number of panels on the NNW aspect is higher than the shed's southern aspect. All things being equal you'd fill southern aspects, All that matters is average cost per unit generated. It requires a bit of home work @banie01 but you'll find the price point where it makes sense to do one over the other.

Taking guide price as 1200 per kWp the 8KWp system is 9600 Euro (Assume equivalent to 6KWp fully south facing).

The full south facing 7.3KWp system is 8760 Euro. If the additional cost is less than 840 Euro you're onto a winner for sure, after that the maths gets murky but I'm betting the additional costs will be significant.

All this is speculative until you have a price for both scenarios, so feel free to solicit quotes for both.

micks_address

https://www.boards.ie/discussion/comment/120128187#Comment_120128187

got seai email today that grant was approved and eft should happen in next few days.. very quick on seai side.. installed took two months to process.. little longer.. closer to 3.. holidays in middle didnt help.. could have saved a month from time if ber was done sooner..

slave1

https://www.boards.ie/discussion/comment/120130622#Comment_120130622

10mm2 is plenty to allow your inverter in the white outlined outbuilding rather than your attic, could save invading the fabric of your home and running big cables from your attic to your consumer unit

Manion

That's a good point and with it already wired for Cat 5e/Cat6 you could install the whole set up out there and have the CT clamp still monitoring your consumer unit (assuming the cable goes to a common utility space. Thinking on it, it's probably much neater that way and no hole in your main roof. That's a good way of look at it.

graememk

https://www.boards.ie/discussion/comment/120134753#Comment_120134753

Hands Down, Put them on the shed.

10mm2 is planty.

There is Wireless RS485 transceiver if you dont have a way back to the consumer unit/meter box you can fit to a solis.

banie01

https://www.boards.ie/discussion/comment/120134577#Comment_120134577

https://www.boards.ie/discussion/comment/120135617#Comment_120135617

https://www.boards.ie/discussion/comment/120134753#Comment_120134753

Thanks for the info folks. Especially with regards using the shed for the entire install.

blackbox

Dummy question here....

Will a 400W panel ever output 400W in Ireland?

If so, what would the same panel output if nearer the equator where the light is much more intense - say in the Canary Islands?

.

unkel

https://www.boards.ie/discussion/comment/120141056#Comment_120141056

Very good question. And yes, a 400W panel outputs 400W very often in Ireland. It could even do that in winter, were it not for the fact that the the angle at which most panels are fitted are not optmised for the low winter sun. Contrary to popular belief, PV panels work better, the colder it is. One of the reasons why PV in Ireland works better than in say the Netherlands or Germany

The rated output of panels is measured under certain circumstances, and these are not optimal circumstances, so that answers your second question, yes panels can produce significantly more than their rated output. I don't have any figures for this but I recall seeing people posting results of their arrays producing 25% higher than the rated wattage

graememk

https://www.boards.ie/discussion/comment/120141056#Comment_120141056

Short answer yes.

Long answer, it's complicated.

The factors at play here, is ordination, angle, solar irradiance and most importantly temperature.

The hotter the panel the worse it preforms.

So on a good day in may, with a nice cool breeze it might even over perform in Ireland.

slave1

Perfectly South facing at 53degrees at true noon in May then yes, anything outside them will lessen the chances.

For the Canaries the panel would be much flatter to the sun, I dunno, say 80degrees but the Canaries is hot so this will drop generation

unkel

Also a good comparison is that a south facing panel at the best possible angle in the best location in Ireland will produce about 50% of a panel in the best location in the world. That's total production per year.

Ireland really is rather good for PV...

Hellrazer

Heres a question. So now that the South panels are done I have room for 4 panels on the shed - 2 east and 2 west. I want to use those micro inverters that plug in but what would the best way to wire them be - 2 separate micro inverters?? Or can you buy a micro inverter that does 2 strings? Im reckoning I can get another 1.6kw on the shed if I buy right.

Thats just the start - I can also get 4 panels NE facing on the extension but Id say E/W would be a better start.

slave1

How long is your install done? If only recent I’d wait a year and track your generation and usage to see is the investment worthwhile…

allinthehead

https://www.boards.ie/discussion/comment/120141860#Comment_120141860

https://www.rexelenergysolutions.ie/product/bpe-quad-microinverter/

You need a cable from a distribution board wired through an rcbo, then a rotary isolator close to the shed. The inverter then gets wired to the isolator and the panels just plug in. Easy. You'll need to get an electrician to do the wiring as far as the isolator. These are available off the shelf from Kellihers Electrical.

banie01

Another question and I hope this one borders more on a sanity check than it does total noob 😉

I appreciate the advice re: location and making best use of my shed if I go down that route already offered.

I've had a few quotes and a couple of site visits from installers. Those that have called all seem to be leaning towards a 3.6kw setup with 8 - 10 panels on the main house roof. Space and orientation dependent.

Now if I was to go with a 3.6kw set up, but overspec the hybrid inverter to a 6kw model. Would that be of benefit both for maximizing any deemed export? As well as allowing me the opportunity to more easily add additional string of panels via either a shed or pergola install wired directly back to the inverter?

There's been a sudden drop in the budget I can allocate but I want to be sure I don't limit my options on expanding the system when funds allow later.

DC999

https://www.boards.ie/discussion/comment/120150418#Comment_120150418

You're right to consider the options ahead of pulling the trigger. Smaller systems cost more per 1kWp as the labour is the big cost. I’ve a small roof so I got caught with that. 3.6kWp is a small system. And output is lower if not South facing, or close to South. I've 5kWp E/W split and would love more but have no space anywhere. A panel costs the installer under €200. So I'd suggest go to what your budget allows now, and ignore what you might add to it in time.

From what I read at the time, the inverters perform to a higher efficiency when they heavily ‘loaded’ from the panels. As in they are working hard. So a 6kW inverter won’t be getting that from 3.6kWp of panels. I've no idea if that's a tiny % efficiency gain though in the real world. Normally we undersize the inverter as the panels rarely get to 100% of capacity. You're looking at the opposite.

I can’t see the gain tbh - unless you’re going to DIY adding more panels in time, and they leave you a spare string on the inverter for that (which might impact the design now if you’ve more than 1 direction or some get more shading). Most inverters only have 2 strings, so if they plan to use both, then don’t get a larger inverter. Ignore deemed export as a way to determine an inverter size as that will disappear at a point in time.

Options:

Others have added DIY on sheds using microinverters. In which case the main solar stays as is now, and you add a 2nd separate system. 

If upgrading in the future, could always sell the inverter yourself. There's a market for those.

Ginger83

https://www.boards.ie/discussion/comment/120130622#Comment_120130622

Do you have a link to how you showed the sun's direction with times over your home?

banie01

https://www.boards.ie/discussion/comment/120150574#Comment_120150574

Of course, from an earlier post.

https://www.boards.ie/discussion/comment/120130622#Comment_120130622

https://www.boards.ie/discussion/comment/120150502#Comment_120150502

Thanks for that. For me, the gain isn't an immediate one rather its future proofing and also allows (as I understand it) my deemed export to be calculated on the 6kw basis? As I read it, deemed export is based on inverter size? Rather than worry about swapping and reselling a lower rated inverter and the Reci costs for swapping? I can for the sake of an extra couple of hundred spec that capacity now,rather than pay twice.

I would also ensure that the initial array install is on a single string. Leaving me the 2nd string to be populated by the additional south facing panels when funds allow.