The Field Guide to Solar Panel Positioning (And Why Your Off-Grid Asset is Still Underperforming)

You’ve done the hard part. You’ve invested in a state-of-the-art deployable solar tower, complete with high-capacity lithium batteries and a 400W solar array. You get it to the site, deploy the mast, and… a week later, you’re getting low-battery alerts.

What went wrong?

In the world of off-grid power, a system’s failure is rarely due to a single faulty component. It’s almost always a “death by a thousand cuts” caused by a flawed power budget. And the biggest, most overlooked, and most preventable flaw?

Poor solar panel positioning.

Just deploying an asset isn’t enough. Where and how you deploy it makes the difference between a self-sufficient asset and one that needs an expensive site visit every other week. Here’s what you need to know.

The #1 Enemy: Shading

Before you even think about angles or direction, you must think about shading.

We cannot overstate this: Even partial shading is catastrophic for a solar panel’s output.

A common misconception is that if 20% of a panel is in shadow, you lose 20% of your power. In reality, you could lose 50%, 80%, or even all of it. Modern panels are wired in “strings” of cells. If one cell in a string is completely shaded, it can act like a “kink in a hose,” blocking the flow from all the other healthy, sun-drenched cells in that string.

When you’re on site, you need to become a keenly observant on where the shadows are. Look for the obvious, but also for the non-obvious shadows that will appear at different times of the day.

• Obvious Culprits: Trees, adjacent buildings, and large structures.
• Non-Obvious Culprits:
  • The asset’s own mast or antennas (casting a thin but constant shadow).
  • A nearby light pole or another CCTV tower.
  • A welfare cabin or site office that’s “only” there for a few months.
  • The ridgeline of a hill that will block the sun after 3 PM.

Your Goal: Find a location with a completely unobstructed view of the sun’s path from at least 9 AM to 4 PM.

The Big Question: Where Do I Point Them?

This one is simple. If you are in the Northern Hemisphere (like the UK), your panels must face Due South.

This ensures the panels are facing the sun for the longest possible period as it moves across the sky.

• What if I can’t point perfectly south? A South-East or South-West orientation is acceptable, but you will see a drop in your peak generation.
• What about East/West arrays? You sometimes see these on large domestic roofs to “flatten the curve” by catching the morning and afternoon sun. For a deployable asset with a single array, this is not an efficient approach. Always aim for South.

The “Winter-Proofing” Trick: What’s the Best Angle?

This is the key adjustment that makes the biggest difference in winter.

For a panel to work at its best, the sun’s rays must hit it at a 90-degree angle (perpendicular).

• In Summer: The sun is high in the sky. A “flatter” panel (e.g., 30-35 degrees) works great.
• In Winter: The sun is very low in the sky. To catch those rays, your panel needs to be angled up much higher.

Many deployable towers have their panels fixed at a “compromise” angle, often around 35-40 degrees. This is fine for summer, but it’s terrible for winter. In low-light conditions, those low-angle rays will just “glance” off the panel, and your generation will plummet.

The Rule of Thumb for a UK deployment:

• Best “All-Season” Angle: 50-55 degrees.
• Best “Winter-Proof” Angle: 60-65 degrees.

By tilting your panels higher, you are perfectly positioning them to catch the low winter sun, dramatically increasing your “Power In” and helping you survive the dark months.

How Do You Know If You Got It Right? Stop Guessing, Start Measuring.

You’ve deployed the tower. You avoided the big tree, you pointed it South, and you tilted the panels high. But how do you know you did it right?

How do you know that a new building on the horizon isn’t casting an unexpected shadow at 3 PM, killing your afternoon charge?

You stop guessing, and you start measuring.

This is where a smart monitoring platform becomes essential. By monitoring your Daily Solar Yield (kWh), you get a daily “report card” on your asset’s performance.

With a platform like Insytly, you can:

1. Get a Daily Yield Figure: Log in and see exactly how much power your array generated yesterday (e.g., “1.1 kWh”).
2. Compare Assets: Look at your fleet on a single dashboard. If “Tower A” (in an open field) generated 1.1 kWh but “Tower B” (near a new site office) only generated 0.6 kWh, you don’t have a battery problem – you have a positioning problem.

This data turns your off-grid solar panel positioning strategy from a ‘best guess’ into a data-driven science.

Key Takeaways for Your Next Deployment

1. Shading is Your #1 Enemy: Be relentless in avoiding it. One shadow can kill your entire array.
2. Point South: It’s the simplest and most effective rule.
3. Tilt for Winter: Angle your panels high (60-65°) to catch the low sun.
4. Monitor Your Yield: Use your monitoring data to prove your positioning is correct and to spot problems (like new shadows) remotely.

Ready to see what a purpose-built monitoring solution can do for your fleet? Book a demo with our team with this link.