Solar panels are a popular fixture in many a modern home, however they are not always simple to install. I recently chatted with Yen Dai from Environment Logic about the common pitfalls and the best advice for those planning on installing solar panels. Here’s what he had to say:
Time and time again a client will come to us after obtaining planning permission, very pleased that their house designer has factored in for X number of solar panels. A great deal of architects think solar design is straightforward, ie you just put them on the roof, but there are things that need to be taken into consideration.
For example, many architects do not understand the full extent of shading, which greatly affects the power output. So clients should engage with a specialist solar panel company right at the very beginning and put the expert in contact with their house designer to collaborate. If we suggest solutions once the scheme is finalised, like moving roof windows, some architects can be reluctant because it might spoil the aesthetics.
But if we engage with a client in the preliminary stages, we can avoid these issues altogether. Even more reason to engage a solar professional early on is if an in-roof system is required – where the panels are installed flush into the roof. While an architect can reach out to a manufacturer to get dimensions, many don’t realise that there needs to be flashing (a tray for the panels).
Even if this is highlighted to them, no one then explains that there should be a buffer around the edges – one and a half tiles on the sides, and two rows on the top and bottom of the array. When we come in late and see that there physically isn’t the space to allow for the flashing or minimum row of tiles, it means the client will have to lose some panels – so people get very disappointed.
People forget the impact of shading. The minute you get any form of shadow on the panel – even something as minute as a telephone line – it has an effect on the power output. Avoid trees full stop – even a bare tree, without leaves, casts a shadow. The same issues apply to chimney stacks, TV aerials, satellite dishes and dormer windows.
If you put panels between dormers, even if the house is facing dead south, with the most sunshine available, you’d be looking at a massive reduction in power output. In the morning, the panels on the east side of each dormer will be working fine, but all those on the west will be in shade. Then in the afternoon, it’s the reverse. The system is working at 50% efficiency because the design hasn’t considered shading.
One thing to note is that your solar system also doesn’t necessarily need to be installed on the house. If you’re keen on designing in a dormer or can’t avoid shading from chimney stack, but you have a garage or other outbuilding with a sunny outlook, consider fitting your panels there. They then just need to be wired back to the main house.
The electrics! Solar PV panels generate electricity in direct current and we need to install an inverter to make this suitable for your home. These are boxes of electronics measuring about 45cm by 60cm that hang on the wall, usually in the loft. Ideally, we like to keep them as close to the panels as possible. A solar specialist can explain where a reasonable position might be at the design stages.
There’s currently a trend for vaulted ceilings, which means you don’t have a hidden loft space in which to conceal the inverter. In this case, we may move it to the plant room. This is fine, but the solar company, the builder and the electrician all need to be aware, in order to run the appropriate cable and mitigate any potential loss in voltage.
Battery storage is also key and should be on the ground floor – normally in a utility room or garage. Some batteries need to be located in close proximity to the fuse board or the inverter – this would be a scenario where we install it on the lower level. We’ve had a number of people asking to put the battery in the loft but it’s not good practice – legally you need a dedicated fire alarm for this if it’s upstairs, separate from any others in the property.
Also think about your future needs. Anticipate that you might have an electric vehicle and we can get the necessary fuse boards and equipment in place while a new build house is still being wired up.
A common misunderstanding is that the panels can only face dead south – where the sunshine is greatest. Imagine this orientation is 0º – if you go up to 90º east or west, you only lose about 15% power output. So, a southeast or southwest position is still fine.
Pitch is also misconstrued – while 30º is ideal, the closer you are to dead south, the more leeway you have. You could have an angle of 20º to 55º and not lose much power. We can also install panels onto a flat roof. An A-frame is required to elevate them though, because level panels cause water to pond on top and encourage moss growth, which can be devastating to the power output.
In general, solar panels fall under permitted development. However, if you’re in an area of outstanding natural beauty, conservation area, working on a listed building or installing a ground mount, you will need planning permission, so be aware of this.
Don’t change your mind without telling the installer! We’ve had a project where the couple decided, at a later stage, to put in a log burner with the flue coming straight through the roof. They didn’t tell us. When we climbed up to the roof to install the panels, it was impossible – the flue was right in the way
Most importantly, engage with a specialist early. We can save you so much stress and wasted time by mapping out the system alongside your chosen house designer.
To find out more visit Environment Logic