I’ve bought solar panels, where should I install them?
- 26 Mar 2021
- 7 min
Buying solar panels is simple. Picking the right place for them, checking the surface and possible shadings, adjusting the angle – not so much. We are here to help you nail it.
Roof is the best option for a small-size solar system
2.5-2.7 pounds per square foot is the average weight of a crystalline solar panel
Since the space on the roof isn't usually used, putting solar panels there is a great option. Before the installation, make sure your roof is able to bear your solar system. It is recommended to call in a specialist so that they could check the surface. It is also important to put the panels where they aren't shaded by trees, buildings, roof parts or other panels.
The average lifespan of solar panels is 25 years. If your roof is old and leaky, replace it before the installation of a solar system. You see, if the roof starts to collapse with solar panels already installed, it is going to be very costly to detach and reinstall them. PV modules can even prolong the life of a new sturdy roof just because they are made of durable materials.
All roofs are different, and so are the installation methods. Here is our full guide on how to install solar panels on different rooftops.
Ground PV installation needs more space, but is easy to adjust
As an alternative to the classic rooftop solar system, you can put your panels on the ground. This method of installation has its pros and cons:
• Adjustability. With a rooftop system you are limited in the directions and angles your panels can be set. Ground installations are much more adjustable: you can turn and tilt the panels freely.
• Scale. Space can become a constraint with rooftop installations if you have too many solar panels. Systems of a big scale and solar farms are typically installed on the ground. Besides, in ground installations you can use panels of a larger size to get more electricity out of a single panel. In rooftop installations 72-cell and 96-cell are often just too hard to fit.
• Accessibility. If you are installing your panels on the ground, it's easy to inspect them: there is no need to climb the roof.
• Maintenance. Solar panels on the ground tend to get dirty quicker than the ones on the rooftop. As a result, you have to clean them more often if you want to keep the production levels high.
• Space. While you can place larger installations on the ground than on the roof, they take up the free space of your yard or a field. The space on the roof is rarely used anyways. On the contrary, free ground space can always come in handy if you decide, for example, to set up a pool or a garden.
• Shading. Ground solar systems are more susceptible to shading from trees and buildings around. If there isn't enough space between modules, they overshadow each other.
It's also possible to put solar panels on walls. The downside here is expensive and complicated installation. Plus, you get lower efficiency, since you can't set your panels at a good angle, and they often get overshadowed.
Orientation: Make solar panels face south in the USA
Solar panel direction is one of the most important factors influencing the efficiency of your system. Ideally solar panels should be positioned perpendicularly to the sunlight. Thus, in the northern hemisphere – in the USA, Europe and Asia – the best direction for solar panels to face is the south. In the southern half of the globe – in Australia, South America and South Africa – you turn them to the north.
Getting perfect positioning isn't easy. If you install your panels on the roof, the directions they can face are predetermined. What's more, there are very few houses built according to the cardinal points. So it's likely that your panels will be turned to the south-east or the south-west. Such positioning will make them generate 7-8% less energy in comparison to the PV modules facing south. However, you can get the best out of an imperfect solar panel orientation:
• When panels in the USA are facing south-east, they get more sunlight in the morning but less in the evening. It can be useful for those who want to cook meals in the first hours of the day, warm up the house after a cold night and so on.
• If panels are turned to the south-west, they generate the majority of daily amount of energy in the evening. Thus it can be good for those who return home from work and turn on all the appliances in the later part of the day.
Inclination: Set an angle to your latitude
When we talk about the angle of solar panels, we mean their vertical tilt towards the equator. Getting it perfect is tricky, but luckily the angle matters much less than the right positioning of solar panels. If you don't want to dive too deep into the possible complications, choose a tilt between 30 and 45 degrees – it always works well in the USA.The problem is that there is no optimal solar panel angle, or rather it differs from season to season. Some experts suggest setting an angle equal to your latitude. It works perfectly for spring and autumn, but not for summer and winter. In the winter, the sun is lower, so it's better to have your panels ~15 degrees higher than the latitude. On the contrary, in the summer subtract ~15 degrees from the latitude.
The additional energy that you gain by adjusting solar panel angle seasonally isn't really worth the hassle. Fixed angle allows panels to receive ~71.1% of the available energy. By fixing it up four times a year you only raise the percentage to 75.7.
As a way to maximize the energy production, you can add solar trackers which make panels follow the sun at all times, eliminating the problem of an imperfect angle. It is possible to collect 25-30% more energy with them, but a solar system with solar trackers is much more expensive. Besides, the warranty for them lasts only for 5-10 years. Panels aren't afraid of hurricanes and storms, but trackers are. Overall, solar trackers can be justified only when maximum energy is a must.
Learn about the latest arrivals and discounts first!