Calculate exact solar production from your roof based on its direction, tilt and zip code

Calculate exact solar production from your roof based on its direction, tilt and zip code

What direction should solar panels face?

Written by Andrew Sendy

Updated August 12, 2021

8 minutes read

Categories: Solar 101

Solar panels should face south for any home in America to obtain maximum power generation.

However, solar panels can be orientated on any roof that faces south of either east or west. 

So directions like southwest or southeast are fine.

Panels mounted on a standard pitch roof facing east or west will produce approximately 15% less output than panels mounted on a south-facing roof of a standard pitch.

However, the economics of installing solar panels on a roof that does not face the south still usually stack up for the homeowner.

Solar panels installed on a roof facing southwest or southeast will generally produce about 8% less power than the same panels in the same climate on a south-facing roof.

How much will your roof direction affect the output of your solar panels?

This depends on both the direction of your roof and the pitch of the roof.

The flatter the roof the less solar energy production falls when panels face east or west rather than south. The steeper it is the more it is an issue.

Over the last few years we have created the first online solar production calculator that works out the exact solar production that you will get for your home based on the direction and steepness of your roof.

How does our solar panel roof direction production calculator work?

We use AI-powered software to scan your roof online and determine the direction and slope of each of your roof sections. We then place panels on your roof in the best available places and measure the specific output of these panels based on their positions.

This gives us an accurate output from which we calculate the cost and savings you will get based on your local solar prices and the amount you pay your utility company for electricity.

You can enter your zip code at the top of this page to get started.




solar installer working on solar panels

Learn more about solar panel installations as we explore panel positioning and how it affects your energy output.


How can you optimize your solar system's efficiency?

Until now, we’ve inferred that mounting fixed solar panels in either south direction can help you achieve a greater return on your solar investment.

However, fixed solar array systems that face south or west can only produce energy for a limited number of hours each day.

In fact, you can track the sun all day long and achieve optimal solar power output — no matter the season, location, or time of day — by using solar panel trackers.

Utilizing solar panel trackers to maximize your solar system's performance

Solar panel tracking systems can improve a system’s output by ensuring constant, direct exposure to the sun, both during the day and across seasons. Axis trackers generate more electricity by using about the same amount of space as fixed systems.

The image below shows that dual-axis trackers can achieve a noticeable boost in solar panel output, especially during the fall and winter months.

nergy production for 1 kW of solar PV capacity in LA, California, with different types of solar tracking, during different seasons

Solar energy production in Los Angeles, California, during different seasons. Image source: EIA

Seems ideal, right? You might even be wondering, “Why doesn't everybody get a tracking system?” Well, the reason is quite simple: solar trackers are proportionately much more expensive than the value of the extra power they produce.

For instance, for a standard 4 kW system, the typical price for a fixed, ground-mounted array is about $14,000. A single-axis tracking system serving the same sized home costs about $22,000. This is a premium of 57% over the cost of a stationary array — for a solution that will only increase production by around 25-30%, at best.

To learn more about the value proposition of solar trackers, read this article: Are solar axis trackers worth the additional investment?

What if your roof doesn't face south?

Ideally, your rooftop solar power system should be facing south for maximum efficiency. Of course, this isn’t always possible: many homeowners don’t have roofs that face in that direction!

The good news is that this is not a dealbreaker. There are plenty of homeowners in America without south-facing roofs, who have solar panels installed and are enjoying huge savings on their electric bills.

Here are some workarounds for homeowners who don’t have south-facing roofs:

Install solar panels on your roof anyway

You can install solar panels facing west or southwest; in some cases, this works out to be as or even more profitable because of time-of-use billing.

If that is not an option either, then you can simply install more solar panels, which will help compensate for the decreased level of sunlight.

Install your panels on a wall

If your roof doesn't face due south, you could install solar modules on a south-facing wall instead.

This will only work if the wall receives lots of direct sunlight, i.e. it is relatively shade-free. Trees, bushes, or other buildings that cast shadows on the wall will make the solar panels less efficient.

You should also be aware that installing solar panels vertically tends to be more expensive.

Install a solar array on the ground

You can also install a ground-mounted solar system in your yard. This is less expensive than creating racks on your roof or hanging them on a wall, but it does require a lot of yard space.

One of the best aspects of ground-mounted solar panels is easy maintenance. You can brush leaves or snow off of them without having to climb onto your roof.

Other technological advancements for solar panel direction

Researchers are working on ways for solar panels to achieve maximum energy output without difficult and/or costly manual adjustments. Here are some of the more promising developments:

Despite these advancements, no technology currently offers more cost-effective electricity production than traditional fixed-mount solar panels — and it’s impossible to say if and when that will ever change.

In the meantime, we recommend that you use our solar roof estimate calculator to learn everything you need to know about installing solar panels on your roof.


South-facing solar panels provide you with maximum energy savings for your home. But no matter what direction your roof faces, you will still see a significant impact from solar power.

Solar panels will save you money and energy year-round - in any weather, rain or shine.


Author: Andrew Sendy Andrew Sendy LinkedIn

As chairman of Solar Investments Inc and chairman of the largest solar panel installation company in South Australia, Andy is passionate about solar power. With his unique working background he writes on the residential solar industry in America from a unique perspective.