Mpfana Manu is a mechatronic engineer who's working in green energy electronics products.
Solar panel installations are better done by the technicians. But if you're anything like me, you like to get your hands dirty doing it yourself, this article is for you. Here, you going to learn what you have to do for a successful solar panel installation.
If the solar panel installation is for a home, there's no necessity to get involved in the complicated mathematics and designing. Here are the assumptions I have made. Please take note here.
- I assume you already know how many solar panels you need to install for your home. If you don't know yet, read the guide to determining how many solar panels you need here.
- I assume also that the system you want to install is for a residential home. Home installations are less complicated. You possibly cannot use this guide to build a system that cannot afford to fail. For example, solar panels that are used to power drug refrigerators in a hospital are installed after long and complicated calculations to make sure it doesn't fail at any time. Such calculations are beyond the scope of this article.
The performance of any panel installation is dependent on the location and positioning. You may not have much control about the location since your home is fixed but you can play around with the positioning to optimise the performance of your solar panels.
It's the location that determines whether installing solar power is possible or not so we start investigating the location first then investigate for the positioning. Here's what you have to do.
- Do a site survey to investigate the location
- Investigate possible mounting positions
Doing a site survey
If you have never done a site survey for a solar system before, it is best to do it during the day in broad daylight. And aslo, you could take with you a cardboard shaped like your solar array. It'll help you visualize how your solar array would fit in different positions and whether it'll need to be partitioned or not.
The most convenient place to install panels for a home is on the roof. So that's the first place you want to investigate. You'll need a ladder to get up there. Don't assume you can estimate anything while standing on the ground. The world on the roof looks very different than the world you see while standing on the ground. So please get up on the roof.
When you get on the roof you want to check for these things. The shading on the roof, the direction the roof is facing and the strength of the roof.
If there's anything that is capable of reducing the efficiency of a solar power system by over 50%, it is shading. Shadows are the worst enemy of solar panels and you have make sure before installing the solar panels that the shading is clear. You want your solar panels to be exposed to the sunlight from the time the sun rises to the time it sets without being obstructed by shadows of objects in your surrounding.
When you get on the roof, check for any possible objects that might shadow your solar array at any time of the day. If you're in the northern hemisphere, check for obstructions from the east, via the south to the west. If you're in the southern hemisphere, check for obstructions from the east, via the north to the west. If you're at the equator, just check from east to west. You might need a compass to help you with the directions.
If there are no potential objects that can shade your solar array, then there are greater chances that the solar panels will perform at their best after getting installed. If there are obstructions, consider getting rid of them. If there are trees, prune them down.
However, not every obstruction can be dealt with. For example, you can't collapse other people's property for the sake of installing solar panels on your roof. If the shading cannot be removed, you'll have to change the site of mounting your solar array. This will probably increase the cost of installing the solar panels. We'll look at other options for mounting your solar array in a minute.
Direction facing the roof
In the event that there are no shading obstructions on your roof, the next thing your want to check is the direction your roof is facing. The most ideal roof for installing solar panels is that which is facing south/north. For those in the northern hemisphere, the ideal roof will be facing south and for those in the southern hemisphere, the ideal roof will be facing north. At the equator, either north or south is okay.
If your roof is flat or if it is inclined not facing south/north, you'll need to install your solar panels with angled supports. This will make the compact assembly of your solar array and the supports heavier. A heavier solar array needs a stronger roof.
Strength of roof
Solar panels on their own are not heavy. The modern largest solar panel I know weighs less than 25kg. However, when the framing and angled supports are included, the weight of the solar array will be significant enough for you to worry about the strength of your roof. You wouldn't want to install solar panels on your roof only for it to break and fall in your house while you're having lunch with important guests. That would be embarrassing and costly.
There are a zillion roof designs that exist on this planet and that makes it very difficult to give any advise on how to judge the strength of a roof. But you know the kind of roof you have, check the trusses supporting it and the material used to judge whether it's strong enough or not. It would be a smart move to consult an architecture or a builder. He/she can help you make a better judgement about the strength of your roof.
Where on the roof should you mount the array?
Say your roof has no shading and it is strong enough to support all the weight of your solar panels that you want to install.
Where exactly on the roof should you install the array?
Any position on the roof is okay but if possible, try to install the panels at the edge of the roof.
This will make them easy to access in the event of cleaning them or just checking them out while standing on the ground. Your solar array will need cleaning once in a few months to remove dust and dirt that would otherwise reduce the efficiency of your solar panels.
So they'll need to be close enough for a hosed spray of soapy water to reach them. If for some other reason you cannot install the array at the edge, it's still okay to install them elsewhere on the roof but you'll have a tougher time cleaning them.
Investigating possible mounting positions
For a home solar installation, the first place to mount the panels that comes to mind is the roof. But the roof is not all there is, there are other options. In the case where your roof can't be used to mount your solar array, possibly because of shading or not having enough space, you can turn your focus to these other mounting positions.
- Mounting on the ground
- Mounting on poles
Mounting on the ground
This is a better option if your home is in the middle of open space. Farm houses and low density suburbs are very fit for this option. Lets look at the pros and cons of mounting the array on the ground.
- Can be designed to capture radiation both from the sun above and that reflected from the ground
- Easy cleaning of panels.
- System can be expanded easily since there are no space limitations.
- Accumulation of dust and dirt on the panels is faster.
- Needs security and protection from being tempered or vandalized.
Mounting on poles
If you're not in an open space, poles can be erected to hold your solar panel array. And when you choose to mount on poles, installing solar trackers together with the solar array becomes cost-effective.
Solar trackers are cheaper to install when they're being installed on an array held up by a pole.
But wait, what are solar trackers?
Solar trackers are devices that can be installed on a solar array such that the array faces the sun wherever the sun moves, it keeps tracking the sun. These trackers increase the efficiency of solar panels by at least 25%.
Lets look at the advantages and disadvantages of mounting your panels on a pole.
- An array of up to 1000W can be supported by one pole.
- The pole and solar array structure can be made into a shade for other purposes.
- Poles can be used to extend an existing solar system.
- Requires a deep foundation and heavy pole to resist the wind.
- Needs professionals to install it. Please don't mount solar panels on poles on your own. There are necessary mechanical and mathematical calculations that has to be done, otherwise the system will fail or it won't last.
- Difficult to clean.
- Difficult to extend the solar array without planting more poles.
Mpfana Manu (author) from Harare on February 04, 2020:
Always welcome Tawada
Tawada CleanTech from Jakarta, Indonesia on February 03, 2020:
Nice article. Thanks for sharing.
Patrick Kamau from Nairobi, Kenya on January 26, 2020:
Very well written article. Keep informing us about the affordable green energy. I am hoping that one day I will be able to rely on solar energy to run my day-to-day operations that need electric power. Keep them coming.
Mpfana Manu (author) from Harare on January 26, 2020:
Umesh Chandra Bhatt from Kharghar, Navi Mumbai, India on January 25, 2020:
Nice article. Well explained.