Yes. South-facing solar typically produces the most electricity over the course of a year in Wisconsin, but east- and west-facing roofs can still be excellent candidates for solar.
Depending on roof pitch, shade and other site conditions, an east- or west-facing array may produce roughly 80 to 90 percent of what a comparable south-facing array produces. That difference is often smaller than homeowners expect, and orientation is only one part of determining whether solar makes sense for your property.
South-facing panels generally provide the highest annual production in Wisconsin, but “best” does not mean “only.”
Tools like the PVWatts Calculator allow solar professionals to model how changes in direction, tilt and location affect expected production. In many cases, east and west facing arrays can still capture a substantial portion of the solar energy available at a site.
Two factors are especially important:
Roof area is often one of the biggest constraints in residential solar design.
A home may have large east and west facing roof planes but only a small section that faces south. In that case, using additional roof space may allow the system to produce more total electricity even if each individual east or west facing panel produces somewhat less than a comparable south-facing panel.
The goal is not simply to find the “perfect” roof direction. It is to design the system that makes the most sense for the property as a whole.
Orientation also changes when a solar system produces electricity.
East-facing panels produce more during the morning, while west-facing panels shift more production into the afternoon and early evening. South-facing panels tend to concentrate more production around the middle of the day.
That can matter because electricity your home uses directly from solar reduces the amount of electricity you need to purchase from the utility. Compensation for electricity exported back to the grid varies by Wisconsin utility and tariff.
For a household that uses more electricity later in the day, west-facing production may line up well with appliances, air conditioning, an EV, a heat pump or other afternoon and evening loads.
If you are considering battery storage, your daily production and consumption patterns become another important part of system design.
A south-facing roof is not automatically the best location if it is heavily shaded.
Trees, neighboring buildings, chimneys and other obstructions can reduce production throughout different parts of the day and year. An east- or west-facing roof with strong solar access may outperform a more favorably oriented roof that experiences substantial shade.
That is why a professional solar assessment evaluates solar access across the property rather than simply looking at which direction the house faces.
Your utility's rate structure and rules for customer-owned generation can also influence system economics.
Wisconsin utilities have different tariffs governing how excess solar electricity is credited. Some utilities also offer rate structures where electricity prices vary depending on the time of day.
We design around the rules that apply today, rather than trying to predict future utility policy, but understanding your current utility tariff is an important part of estimating the financial performance of a solar system.
When we evaluate a home for solar, orientation is just one piece of the design.
We also consider:
The best solar design considers all of these factors together.
A ground-mounted system may be another option.
A ground-mounted solar array gives us more flexibility to select the orientation and tilt instead of working with an existing roof. Ground mounts generally require more space and can cost more than rooftop installations, but they can be an excellent alternative for homes with heavy roof shade, limited usable roof area or an aging roof.
When both options make sense, we can compare them rather than assuming one is automatically better.
Their annual production can be similar, but the timing is different. East-facing panels produce more electricity in the morning, while west-facing panels produce more later in the day.
Which is more valuable for your home depends on your electricity-use pattern and your utility's rate structure.
North-facing panels receive less direct sunlight over the course of the year and are generally less desirable at a typical Wisconsin roof pitch.
Before recommending a north-facing array, we would usually evaluate other roof planes, another structure on the property or a ground-mounted system.
It depends on the property.
Splitting an array between east and west can spread solar production across more hours of the day, while concentrating panels on one roof plane may maximize production from that particular section.
We model the available options and compare their expected production before making a recommendation.
That comes from the site assessment and system design.
We evaluate usable roof area, setbacks, roof obstructions, shade and equipment requirements before laying out the array and estimating its production.
If your roof is nearing the end of its useful life, it may make sense to replace it before installing solar.
Solar systems are designed to operate for decades, and removing and reinstalling an array later to replace the roof adds expense. As part of our assessment, we look at the condition and expected remaining life of the roof before recommending a rooftop installation.
Do not rule out solar just because your roof does not face south.
East- and west-facing solar arrays can perform very well in Central Wisconsin. In some cases, available roof space, shade and the timing of your electricity use can matter more than having the “perfect” orientation.
The best way to know is to model the property you actually have.
Northwind Solar evaluates your roof, shade, electricity usage and utility requirements to design a system based on realistic production estimates, not a one-size-fits-all rule about which direction your home faces.
Northwind Solar has been designing, installing, and servicing solar in Central Wisconsin since 2007. We are a worker-owned cooperative, our designers and installers are NABCEP-credentialed, and we back our work with a 10-year workmanship warranty.
Tell us about your site and we will model your actual production, show you the assumptions behind the numbers, and answer your questions with no obligation.
Request a free estimate | Call us at 715-630-6451