Solar inverter, under panels

Is my House Suitable for Solar? What we look for when checking a home's solar suitability in Ireland

Is my home suitable for solar panels?

That's a question we get a lot and would be only too happy to help you with.

We look at a lot of factors when deciding if a house is suitable for PV solar panels. One of our most important jobs is to help a homeowner decide if solar is a good idea in the first place.

For a lot of homes in Ireland solar is a great addition, but we do (and have) recommended people against fitting solar where we think it would not be a good investment for their pocket or the environment.

There are 5 main factors to consider when deciding if your home is suitable for solar:

Let us do the hard work

The below is just in case its of interest for you. We are more than happy to check the suitability of your home for solar for you, that's our job. Its quick, and its free. If you'd like numbers for your own home, including costs and predicted electricity generation numbers, just fill in the solar PV quote form and we'd be glad to help.

Your Roof

Roof Type

Pitched roof types

Solar panels can be fitted on just about any roof type. They work very well with all the main roof types here in Ireland.

Flat concrete tiles, fibre cement slate, pan tile / roman tile / wavy tile and natural slate are the most common types here in Ireland and solar panels can be fitted to any of those. Natural slate takes a little longer than the others, and so the installation process might take half a day longer.

Flat roof types

Solar panels can be fitted to just about any type of flat roof without compromising it's water tightness. In this case, a frame is added to tilt the panels up to face the sun.

Roof Direction

If you have a flat roof then we can point the your solar panels any direction, which normally will be south.

If you have a pitched roof though the direction the panels will face depends on which direction your roof is already pointing (as you cannot put frames onto pitched roofs to point the panels in a different direction).

Due South: most power output

A south facing roof will produce the most electricity. Being a bit off directly south though has minimal impact on production. Anywhere between south-east and south-west will be very similar.

South East / South West: 5% Lower

If your roof faces south-east, or south-west, then your production will be a little lower. The timing of your electricity production will change too. South east produces more in the morning, and south west more in the afternoon / evening.

East / West: 20% Lower, but more useful?

If your roof faces due east, or due west, the production will be about 20% lower than a south facing roof.

The production numbers though are still very good and make a savvy financial investment. There's a side benefit to east / west facing solar arrays, as they produce the most electricity when you need it most.

Most homes use their largest amount of electricity in the morning (when east facing panels are producing), and late/afternoon evening (when west facing panels are producing), as people turn on their kettles, showers and ovens.

There's a good argument for east / west facing arrays as it means less need for battery storage as you can use the power directly. You could also cover both sides of your roof as both are pointing in a useful direction.

Northerly: not worthwhile in Ireland

As you move to pointing north the production from solar panels rapidly drops off, and we would not recommend it as a good financial or carbon-footprint reducing investment.

"Azimuth", the technical term for direction

In solar calculation reports you'll see the term "azimuth", normally quoted in degrees. That's just the fancy term for which direction the panels will be facing.

  • 90° = East
  • 180° = South
  • 270° = West

Is my roof big enough for solar?

Very likely is the short answer. Most irish houses have ample space on their rooves to make electric solar panels worthwhile.

For example, a typical 2 bed mid-terrace house might have enough space to fit a 3kW solar panel array on it's roof, which is big enough to produce almost half the electricity that family might use in the year.

Here's a ball park guide to the amount of power that common roof areas would produce:

Solar Panel Area System Size (in kW) Approx Annual Units generated in Ireland (if facing south)
10m2 2.1kWp 1806kWh
15m2
typical 2 bed mid terrace
3.15kWp 2709kWh
20m2
typical 3 bed semi-detached
4.2kWp 3612kWh
25m2
typical 4 bed stand alone
5.25kWp 4515kWh
30m2 6.3kWp 5418kWh

The above numbers are the area covered in panels. Due to planning permission rules here in Ireland you cannot fill the whole face of the roof. You need to leave a margin free from panels:

  • Top of roof (by the ridgeline): 0.25m left free
  • Bottom of roof: 0.5m left free
  • Sides of roof: 0.5m left free if end of roof, no free space required if mid-terrace.

If you are doing your own back-of-envelope numbers do keep in mind your roof is on an angle, so it has more area that a flat roof would. A typical home in Ireland has a 30° slope on it's roof, so giving you 15% more area to fill with solar panels than a flat roof on the same building.

More about Ireland's solar planning permission rules

My roof has lots of angles

It would depend in that case. Lots of small triangles can be difficult, as solar panels are rectangular. Often though it can be fine with a bit of planning in both solar panel positioning and inverter design.

Unsure about your roof and solar? Just ask.

If you are not sure if your roof would be suitable please do feel free to fill in our solar panel quote form. We can quickly have a look at your roof on google maps and let you know what might be possible. It's quick and entirely free. We would give you quick quote including guide numbers to both costs and projects solar generation figures to help you decide if solar PV is the right choice for your home.

Shading & Solar Panels

Shading can be an issue, and should be taken into account before deciding is solar is a good idea, both for your pocket and for the environment.

Neighbouring buildings and trees

If your roof spends a lot of time in direct shadow then solar might not be the best choice. A bit of shadow early or late in the day is not really an issue, but direct shadow for significant parts of the middle of the day would be.

You do not need to be able to see the horizon from your roof. As long as you can see most of the sky it is normally fine.

If it helps, the sun hits a bit over 60° in the sky during mid summer in ireland, whereas mid winter it's nearer 15° on the shortest day.

Chimneys and dormer windows

One item creating a shadow tracking across your panels is not usually an issue. With a bit of planning in how the panels are wired up and inverter planning then we can mitigate for such.

If your roof has many items causing lots of shadows that can affect the production. Let's say you've a large chimney breast in the middle of your roof plus two dormer windows, with just small gaps in between. In that case its possible that the gaps are in shadow too much of the time to be worth putting panels in there.

Really though, to know for sure we'd need to take a quick look. The direction your roof faces is another important factor in looking at shadows.

Unsure about shading on your house? Just ask.

Again if you are unsure please don't hesitate to ask. We can have a quick look to see if shading would be an issue or not for you. We can see a lot just from google maps, and also we have drones so we can check for shading issues from a roof-height perspective. Just get in touch if you'd like to chat more on this.

We will always be straight on this. If we think solar would not make economic sense for you due to solar, we wil always tell you that.

Electrics

When our engineers do the site inspection before giving you your finalised quote, they will check your fuse board and electrics. This is required, as well as being a very good idea too!

Modern fuse boards very rarely need any work. The only issues we see are on particularly old electrics and it's usually around missing earth bonding or another issue with the earth.

If we see any problems like that, we'll let you know and it might be something you have to get rectified before solar panels can be added to your home.

This is only a good thing for your home though. It is highlighting places where safety has fallen behind modern standards and usually the improvements are relatively easy to do.

Hot water

A solar immersion diverter is an optional extra that takes an spare power not required by your house and uses it to heat your water tank via your immersion element.

If you would like that you need to have a hot water tank that has an immersion element in it. You do not need to have a separate, extra immersion element just for solar. The one element can be used by solar and you can turn it on manually just like before whenever you like too.

If you have a hot water tank that does not have an immersion element, you can add a device called a Willis heater. Effectively this adds a immersion heater outside your tank that circulates the hot water into your tank - very clever!

They are relatively cheap, and you'd need a plumber to install it before we wire it up. Just get in touch if you'd like to know more about them.

A better use of spare power?

There is no need to feel compelled to add an immersion diverter to save wasting power any more. From 2022 you get paid for any unused electricity your panels generate that gets sent back to the grid, which is a great use of spare electricity you make.

Grant

Your house will almost definitely be eligible for the SEAI Solar Electricity grant as long as:

  • You have a connection to the grid
  • It was build an occupied by 31st Dec 2020
  • This grant has not been claimed before on that property

They are the main requirements that depend on your property, though you can see our page about SEAI grants for solar for more info, or see the SEAI's Website .

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