Solar farms need flat or gently sloped land to work well.
Too much slope can reduce efficiency. It also makes construction and maintenance harder.
Not every hill is a good fit.
That’s why slope and aspect analysis is key when picking locations for solar energy.
Atlas offers a tool built for this job: Aspect-Slope Suitability Analysis.
Why slope matters for solar
Panels work best when they face the sun at a consistent angle.
Steep slopes can:
- Limit sun exposure
- Cause structural issues
- Increase installation costs
- Make access difficult
Even a perfect aspect (the direction a slope faces) won't help if the slope is too steep.
What’s aspect?
Aspect is the direction a slope faces.
In the northern hemisphere:
- South-facing slopes are usually best
- East and west can also work
- North-facing slopes are the least suitable
The ideal aspect depends on your location and design, but slope always plays a big role.
What’s a good slope for solar?
Most solar farms are built on land with slopes of:
- 0–5% for best results
- 5–15% is acceptable with extra planning
- 15%+ is often avoided
The flatter the land, the easier and cheaper the installation.
How to find unsuitable sloped areas in Atlas
Atlas includes a tool called Aspect-Slope Suitability Analysis.
It helps you find only the areas that meet your slope and aspect rules.
Here’s how it works:
-
Open the Aspect-Slope tool
Find it under the Analysis tools in the top toolbar.
-
Set your slope limits
Enter the slope range for each direction:
- North
- East
- South
- West
Example:
- North: 0–3%
- East: 0–6%
- South: 0–10%
- West: 0–6%
The tool will keep only areas within those slope ranges, for each direction.
-
Run the analysis
Atlas will create a new layer showing all suitable areas. Anything outside those limits is unsuitable for solar farms.
What do you get?
The result is a clean layer of usable land.
You can overlay this with:
- Parcel boundaries
- Infrastructure
- Environmental zones
This helps you pick real-world locations that match your design needs.
You can also export the result to share or use in planning.
Common use cases
Use the Aspect-Slope tool when:
- Screening land for utility-scale solar
- Avoiding steep or shaded areas
- Supporting solar permitting applications
- Prioritizing flat, sun-facing locations
It’s also useful for rejecting land early—so you don’t waste time on bad sites.
Want to go further?
You can combine this analysis with other layers:
- Protected areas
- Power line access
- Land ownership
Atlas makes it easy to layer everything together in one map.
Plan smarter solar farms
Using slope and aspect together helps you:
- Avoid unsuitable terrain
- Reduce costs
- Increase energy yield
- Speed up decision making
Try the Aspect-Slope Suitability Analysis in Atlas to find the best-fit land—and skip the bad spots before they waste your time.
