Do East and West Facing Solar Panels Work in Wisconsin?

Do east and west facing solar panels work? Yes. At a typical Central Wisconsin roof pitch, an east or west facing array generally produces somewhere around 80 to 90 percent of what the same array would produce facing due south. That is a real difference, but it is a much smaller one than most homeowners expect, and it is often outweighed by the things that actually decide whether solar makes sense on your property.

How much production do you really give up?

South is still the best single direction for annual energy production in Wisconsin. We are at roughly 44 to 45 degrees north latitude, and a south-facing array tilted somewhere in the mid-to-upper 30s will capture the most energy over a full year.

But "best" is not the same as "only." Modeling from the PVWatts calculator and marketplace data both land in the same neighborhood: an east or west facing array typically gives up roughly 10 to 20 percent of annual production compared with south.

Two things move that number:

• Roof pitch matters as much as direction. On a low-slope roof, the penalty for facing east or west shrinks, panels closer to flat see a big slice of the sky no matter which way they point. On a steep roof, the penalty grows.
• Our latitude pushes toward the higher end. Most published orientation tables are national averages. Wisconsin's sun tracks lower in the sky than Kansas or Tennessee, so we plan around the upper end of that range, not the optimistic end.

That is why we do not quote a number off a chart. We model your specific roof planes, pitch, and shade before anyone talks about production.

Why an east or west roof is often still the right call

You can usually fit more panels

Roof space is the constraint most homeowners actually run into. A house with two large east and west planes may have far more usable area than the one small south-facing section, and more panels at 85 percent output can beat fewer panels at 100 percent.

Panel efficiency has improved substantially and module costs have come down since the early days of Wisconsin solar. That combination is exactly what makes east and west planes practical today when they would not have penciled out fifteen years ago.

The production curve lines up better with how you use electricity

A south-facing array peaks hard at midday. An east/west split flattens that curve: the east side carries the morning, the west side carries the late afternoon and early evening.

That shape matters more than it used to, because of how Wisconsin utilities credit solar. Electricity you use on site offsets your full retail rate. Electricity you export to the grid is typically credited at a much lower buyback rate, often only a quarter to a third of retail, depending on your utility.

So a west-facing array producing at 5 p.m., when the oven is on and the family is home, can be worth more per kilowatt-hour than a south-facing array dumping surplus onto the grid at noon. If you are considering a heat pump, an EV, or battery storage, that afternoon and evening production becomes even more valuable.

An unshaded east roof beats a shaded south roof

This one is not close. Shade is the single biggest production killer we see, and it does not care about your compass. A south plane under a mature oak will lose more energy than an east plane in full sun. We assess shade from trees, chimneys, dormers, and neighboring structures across the whole year, not just the day we visit.

Rate structures can shift the math

Several Wisconsin utilities already offer time-of-use rates, and rate design comes up in every Public Service Commission rate case. If your utility prices late-afternoon electricity higher, west-facing production gains value. We do not design systems around rules that do not exist yet, but it is one more reason not to write off a west roof.

What actually matters more than direction

When we evaluate a site, orientation is one input among several. In practice, these usually matter more:

• Shade, across all four seasons
• Roof condition and remaining life, if your shingles have five years left, that changes the plan
• Usable, uninterrupted area on each plane
• Structural condition and how the array will be attached
• Your electrical service and panel capacity
• Your actual usage pattern and what you plan to add: EV, heat pump, shop, well pump
• Your utility's current tariff, which sets what exported energy is worth

Direction is on that list. It is rarely the item that decides the outcome.

What if you have no good roof plane at all?

Then we look at the ground. A ground-mounted array lets us choose orientation and tilt outright, and it can be adjusted seasonally. It costs more per watt and needs open space, but for a shaded or aging roof it is frequently the better long-term answer. We compare both options in the proposal rather than assuming one.

Frequently asked questions

Do west-facing panels work better than east-facing?

They produce a similar annual total. The difference is timing, west produces more in the afternoon and evening, east more in the morning. West often has a slight edge in value because afternoon production tends to overlap more with household electricity use.

Do north-facing panels work in Wisconsin?

Generally not well enough to recommend. A north-facing array at a typical roof pitch loses a large share of its annual production at our latitude. We would look at another roof plane, a different structure on the property, or a ground mount first.

Is it better to split panels across east and west, or put them all on one side?

It depends on the roof and your usage. A split design spreads production across more hours of the day; a single plane concentrates it. We model both and show you the annual totals and the daily shape.

How do I know how many panels my roof will fit?

That comes out of the site assessment. We measure your usable planes, account for setbacks and obstructions, and lay out the array before producing a production estimate.

Should I replace my roof first?

If your roof is within about five years of needing replacement, yes, removing and reinstalling an array later is a real expense. We will tell you honestly if that is the situation.

The bottom line

Do not rule out solar because your roof does not face south. In Central Wisconsin, east- and west-facing arrays are routinely a good investment, sometimes the better investment, once shade, roof area, and how you actually use power are factored in.

The only way to know is to model the roof you have. If you would like to see what your property would actually produce, our team will walk your site, run the numbers, and show you the assumptions behind them.