Solar panel orientation: Is south the best direction for solar panels?
Published on 20 Dec, 2019 by Jagpreet Sandhu
Categories: Solar panels
Solar panel orientation is definitely something you want to pay attention to if you’re thinking about installing solar panels. The orientation of your solar panels — which refers to the direction in which the solar modules are facing — can have a big impact on your solar power output.
Consider this: two identical 6 kW solar systems, located in the same zip code, can have a power output difference of up to 30% — just because they face different directions!
So, which is the best direction for solar panels?
The US Energy Information Administration (EIA) offers an easy rule of thumb: to achieve the maximum solar system output in the Northern Hemisphere, you should orient your panels towards the south.
Why is this the case, and how important is solar panel direction? Read on to find out.
Why do solar panels need to face south?
The more solar radiation a solar array receives, the more energy it produces - and the more cost effective it becomes.
Because the United States lies in the Northern Hemisphere, the sun moves across the southern part of the sky. Mounting your fixed solar panels towards the southern sky will help capture the maximum amount of sunlight. (If you were in the Southern Hemisphere, you would point solar panels north, while on the equator, you would point them straight up).
Solar power systems facing true south get more hours of direct sunlight throughout the day than panels facing west or true north. Solar panels can get the most hours of direct sunlight if they're facing true south due to the azimuth angle of the sun.
It is important to note that it’s not just solar panel direction that matters; the angle of the solar panels can also affect output. Solar panels should be tilted at an angle equal to the latitude of your home location. To learn more about solar panel tilt, visit this blog: Best solar panel angle: How do you find it — and does it matter?
Find the best solar panel direction for your home with this advanced solar panel layout toolCalculate
Are there any benefits to west-facing solar panels?
It is true that over the course of a year, a south-facing solar panel orientation produces more total energy than if it were to face any of the other directions.
However, there are also benefits of pointing solar panels to the west. West-facing panels add more value for states that have time-of-use (TOU) plans. Nearly every state and the District of Columbia has adopted some type of TOU program; in fact, Montana and Rhode Island are the only two states to not have such a plan in place.
How time-of-use billing affects the best direction for solar panels
While solar radiation is at its peak around noon, the demand for electricity is highest during the early evening hours. West-facing solar panels add more value during these peak demand hours — which coincides with the last few hours of daylight — as they're oriented towards the setting sun.
This means that when you export energy to the grid during peak hours, you not only avoid buying electricity at the higher on-peak rates but also receive net metering credits at the peak rate tariff.
TOU (Time-of-Use) billing for Southern California. Image source: Southern California Edison
If you live in a state with time-of-use billing, such as California, you may benefit by orienting your panels southwest to get the best of both worlds, i.e. achieve high solar energy production and take advantage of time-of-using billing.
How effective is a solar system if it doesn’t face south or west?
Not all homes in America have south-facing roofs. But, the good news is - these homeowners can still go solar and enjoy huge savings on their electric bills.
Here are some workarounds for homeowners who don’t have south-facing or west-facing roofs:
- Increase the solar collector area - If you don’t have a roof that faces in a south or west direction, you can simply install more solar panels on your roof (regardless of its direction), which will help increase the solar collector area and compensate for the decreased solar energy.
- Mount the panels somewhere other than your roof - Installing solar panels somewhere else can help you maximize the benefits of solar. Homeowners who don’t have a roof facing in a south or west direction can mount solar panels on their south-facing walls or perhaps on their garage or storage shed.
- Opt for ground-mounted solar panels - If you have a spacious yard, you can choose to install ground-mounted panels. Panels that are mounted on the ground are easy to install and maintain. Cleaning ground-mounted solar panels or brushing off snow from them is way easier than maintaining rooftop panels. Also, by placing solar panels on trackers, you can adjust the direction of the panels throughout the year in order to maximize the amount of sunlight reaching them.
However, mounting the panels on solar panel trackers will be a more expensive option than a standard solar panel installation. This article explains more - “Are solar axis trackers worth the additional investment?”
All the above options can also work well if you have a south-facing roof that is heavily shaded by trees or buildings.
Every house is unique in terms of roof material, roof orientation, and shade profile. Your best bet is to connect with a solar installation expert in your area to find out what the best direction for solar panels on your home is. A solar expert will take into consideration all the essential factors, including azimuth angle, altitude angle, and solar noon in order to help you install solar panels in the best direction for your home.