What is the best direction for my solar panels?
The direction of your solar panels is an important decision that affects how much energy your solar PV system can generate.
Here is what to know deciding the best direction for your solar panels.
Solar panels should face to the south in the Northern Hemisphere and to the north in the Southern Hemisphere to produce the maximum amount of energy throughout the year.
[toc]
Because the sun shines directly over the equator, solar panels facing south in the Northern Hemisphere use the sun’s vertical rays, whereas placements facing other directions can only receive the sun’s lesser angled, weaker rays.
Also, sun rays hitting solar panels from directions other than the south are more likely to be blocked by shadows cast by nearby structures or key areas on your rooftop, depending on their relative position to the south.
However, depending on your property’s energy demand at different times of day, the best direction for them to face may not be exactly south or north.
However, this can reduce energy production by up to 20%. If you have limited space on your property and cannot place your solar panels in the optimal position (south in the Northern Hemisphere), it is best to place them as close to this direction as possible.
Projects seeking more evenly distributed energy generation throughout the day should try to install solar panels in different directions, with the southeast and southwest being ideal.
Avoid orienting your solar panels to the northwest, north, or northeast, as this will result in significantly reduced power output. (This assumes the project is in the Northern Hemisphere.)
However, there is a distinction to be made between magnetic and true south. The “south” represented by a compass is magnetic south, and it points to the Earth’s south magnetic pole.
On the other hand, solar panels must face the solar or geographic south, which is the direction of the South Pole. By the same logic, if the solar panel is in the southern hemisphere, it should be oriented in the direction of the true north.
Every project has different energy efficiency goals. Projects that are not grid-tied or don’t plan to heavily invest in batteries may find it useful to place solar panels facing in different directions to meet their peaks in energy demand.
Installing solar panels facing different directions will help you to get the most out of your solar panels continuously throughout the day avoiding any potential energy generation gaps while compromising on total energy production.
According to a Pecan Street Research Institute research, west-facing rooftop solar panels produced 49% more power during peak demand than south-facing panels.
Researchers tested 50 properties in the Austin, Texas area. Some of the tested properties had south-facing panels, while others only had west-facing panels, and yet others had both.
They discovered that south-facing panels provided a 54% peak reduction overall, whereas west-facing solar PV panels yielded a 65% peak reduction.
What to expect installing solar panels facing different directions?
South direction
We have already mentioned that the south is the best direction for solar panels to face. South-facing rooftop panels provide the highest energy production and the best option for homeowners who can store energy in batteries.
North direction
For Northern Hemisphere installations, the worst direction modules can face is north, and some people consider installing panels facing north to be almost as bad as installing them upside down.
Depending on the installation location, solar panels facing north can produce up to 30% less energy than panels facing south. Also, the steeper the roof, the less electricity solar panels will produce.
Southeast direction
Solar panels facing southeast will produce approximately 5% less electricity than south-facing panels.
Their energy output throughout the day will be somewhere in between the south-facing panels and east-facing panels. This orientation generates slightly more electricity in the morning than in the afternoon.
Southwest direction
Solar panels facing southwest will produce approximately 5% less electricity than south-facing panels.
During the day, their electricity production will be comparable to that of panels facing south or west. This orientation generates slightly more electricity in the afternoon than in the morning.
West direction
West-facing solar panels generate approximately 15% less electricity than south-facing solar panels.
In addition, they generate less electricity in the morning but more in the afternoon. They reach their peak output around one and a half hours after noon time and produce about one-quarter of their peak maximum just before sunset.
West can be a good direction for people who require a lot of air conditioning during the summer.
It’s also a great option for individuals who are usually out of the house by the time the sun rises but return in the afternoon.
However, because west-facing solar panels generate remarkably less energy than south-facing panels which makes them an inefficient choice.
East direction
East-facing solar modules are similar to west-facing panels in that they produce approximately 15% less electricity overall than south-facing panels, but they produce more electricity in the morning and less in the afternoon.
They are appropriate for individuals with high morning consumption, such as those that use a lot of electric heating on cold winter mornings or individuals who are out of the house in the afternoon.
East and west directions
By installing some solar panels facing east and remaining to the west, the total energy production decreases around 15% than if all modules were facing to the south.
This configuration is known as an east/west split, has the advantage of generating a more consistent output of power during the day, which can assist to improve personal consumption. The system’s energy output will be smoother as the roof steepens.
In most cases, an east/west split can have a different number of modules pointing in either direction.
As a result, if a family needs more power in the afternoon, more solar panels facing west can be placed. An east/west split can accommodate those who are at home all day as well as those who are at home in the morning and afternoon.
| Solar Panel Direction | Efficiency compared to South-facing panels | Energy Output during the Day | Ideal for |
|---|---|---|---|
| South | 100% | Highest energy production | Homeowners who can store energy in batteries |
| North | Up to 30% less | Less energy production | Not recommended |
| Southeast | Approximately 5% less | More electricity in the morning than the afternoon | Morning energy consumers |
| Southwest | Approximately 5% less | More electricity in the afternoon than the morning | Afternoon energy consumers, air conditioning users |
| West | Approximately 15% less | Less electricity in the morning but more in the afternoon | Afternoon energy consumers, individuals who are usually out of the house by the time the sun rises but return in the afternoon |
| East | Approximately 15% less | More electricity in the morning and less in the afternoon | Morning energy consumers, individuals who are out of the house in the afternoon |
| East/West Split | 15% less | More consistent output of power during the day | Those who are at home all day as well as those who are at home in the morning and afternoon |
What if your roof doesn’t face south?
With the exception of the two caveats listed above, your rooftop solar energy system should ideally face south for the best efficiency. Of course, this isn’t always possible: many homeowners don’t have roofs that face south!
The good news is that this isn’t a deal killer. Many homeowners who do not have south-facing roofs had solar panels installed and are saving significantly on their electric bills.
Here are some alternatives for homeowners without south-facing roofs:
Install solar panels on your roof anyway
Installing more solar panels helps compensate for the reduced amount of sunlight.
The solar panels themselves only account for a small fraction of the expenditures of a solar panel installation; you should be able to add a few extra panels without significantly increasing prices.
When a roof part does not face south, this is the choice most homeowners pick.
Install a solar array on the ground
In addition, you can build a ground-mounted solar power system in your yard. This is less expensive than building roof racks or hanging them on a wall, but it does take up a lot of yard space.
One of the most appealing features of ground-mounted solar panels is their ease of maintenance. Without needing to climb onto your roof, you can brush leaves or snow off of them.
Solar panel tracking systems can boost a system’s output by guaranteeing steady, direct exposure to the sun throughout the day and season.
Axis trackers produce more electricity while taking up roughly the same amount of area as fixed systems.
Utilize solar panel trackers
Solar panels do not have to be pointed in a single direction; a homeowner can purchase a tracker, which can revolve them during the day, like a sunflower, so they constantly face the sun.
A tracker can increase a panel’s output by 45%. However, adding trackers might cost hundreds or thousands of dollars, and a less expensive approach to achieve the same amount of kilowatt-hours may be to simply purchase a few extra panels.