Sat, 01 Apr 2023

Many individuals are under the impression that they cannot install solar panels on their roofs for various reasons, including the roof's material, location, shade, or size. Numerous characteristics make a roof more or less ideal for solar. Still, while some roof attributes make installing a rooftop solar system challenging, others do not affect solar energy generation.

In this post, we will examine the direction and angle of the roof as they relate to the performance of solar panels.

Solar panel direction
The orientation of your roof is one of the key determinants of how much sunlight your solar panels receive throughout the day. True south and true north face the axis of the Earth rather than the magnetic poles. For individuals living north of the Equator, the optimal orientation for solar panels is south, whereas those living in the southern hemisphere would install solar panels on rooftops facing north. By aligning solar panels with true south and the azimuth angle - the sun's angle in relation to true north and true south - the optimal orientation for solar panels and arrays may be determined.

Solar panel angle
The angle of your solar panels is the vertical tilt of your solar system. For instance, if your solar panels are perpendicular to the ground, they would have a 90-degree tilt. To increase the efficiency of solar energy collection, solar panels should be positioned to face the sun as directly as feasible. When the angle at which the sun's rays contact the panel surface (the "angle of incidence") is modest, or when light strikes the panel as close to perpendicularly as feasible, photovoltaics create electricity. Therefore, the optimal angle for your solar panels is the one that permits them to receive the most direct, perpendicular light.

What factors determine the best solar panel tilt?
Numerous factors will affect the appropriate tilt of your solar panels. Consider the following factors when establishing the optimal tilt for your solar array:

1. Latitude
Most solar arrays are built at an angle that optimizes sunlight exposure for the given location. For most U.S. property owners, the optimal angle for solar panel installation (on a south-facing roof) is close to or equal to the latitude of your residence, between 30 and 45 degrees. By tilting your solar panels at the same angle as your home's latitude (which implies aiming your panels at that average location), you ensure that your solar power system will provide the maximum average output throughout the year.

2. Existing roof design

It would be ideal if everyone had a roof with the same pitch as their latitude. However, every home is different, and there is no uniform map for solar panel location. Many roofs will have slopes between 30 and 40 degrees, which means that solar panels can be installed flat against the roof and yet generate sufficient electricity to generate attractive returns.

Suppose you are attempting to install solar panels on a roof with a steep slope. It may not be possible to position the panels at the appropriate tilt using conventional racking solutions. Considering that the steep angle of your roof may already exceed the optimal angle for production, the best you can do is lay your panels flat against the roof. Solar panel installation on low-slope roofs will also present challenges and may necessitate specialized racking to tilt the panels at the correct angle. Placing panels flush against these roofs will restrict electricity generation, resulting in diminished solar savings in the long run.

In the event of a flat roof, solar contractors will typically choose to build optimally tilted panel mounting systems. While this permits your panels to face the light more directly, the size of your system may be restricted. Unless your distance and stagger the rows of panels on a flat roof, tilting panels up on a flat roof will result in the panels shadowing one another. Consequently, you cannot install as many solar panels as you would be able to if they were flush on the surface.

Regardless of the slope or flatness of your roof, it is always better to have a professional solar installation mount your panels for optimal production and safety. And, if you're unsure of how solar panels would function with your home and roof, read this article to see if you're a suitable candidate for solar.

3. The season
Solar panels function well over the winter. However, you will normally observe a decline in total energy production during extremely harsh winters due to snowfall lowering the panels' power output. During the winter in the northern hemisphere, the sun is low concerning the horizon; thus, one strategy to combat winter production drops is to set your solar panels at a steeper angle than your latitude-60 degrees is ideal. By doing so, you are preparing your panels to work more efficiently in the winter since they will face the sun more directly when it is lower in the sky. In addition, putting panels at a shallower slant can backfire if snow cannot simply slide off your array. This will result in a prolonged snow cover and a decline in electricity production.

Adjusting the angle of your solar panels twice a year, in the spring and fall, is a second method for reducing seasonal volatility in output. A system at a latitude of 40 degrees can experience a 4 percent energy increase. If you're wondering when it's ideal for modifying your solar panels' tilt, we recommend doing it on September 15 for the winter angle and March 15 for the spring and summer angles.

Which is more important: solar panel orientation or tilt?
While the angle of your solar panels is crucial, the direction your panels face impacts your energy production. Because the sun is always in the southern half of the sky in the northern hemisphere, solar panels should be oriented towards the south for optimal performance, as previously described.

Even if the tilt is appropriate, it is not advisable to put solar panels in a substandard orientation. In Boston, for instance, a solar array inclined 30 degrees south will produce more electricity than one tilted 42 degrees north.

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