Getting the Most From Your Panels

You have invested in solar panels. Now the question is: are they going to produce everything they can, or are you leaving kilowatt-hours on the table because of how and where they are mounted?

Panel positioning is one of the highest-impact, lowest-cost decisions in your solar installation. A well-positioned 5kW array can outproduce a badly positioned 6kW array. This guide covers the fundamentals of orientation, tilt, shading, and mounting — all specific to Zimbabwe.

Face North in the Southern Hemisphere

This is the starting point. Zimbabwe sits between 15 and 22 degrees south of the equator. The sun tracks across the northern sky for most of the year. Panels facing true north (azimuth 0 degrees) receive the most total sunlight across the year.

True north is not the same as magnetic north. In Zimbabwe, the magnetic declination is small (around 5-8 degrees west depending on your location), but if you are using a phone compass, be aware of the difference. The SolMate orientation tool accounts for this.

What If Your Roof Does Not Face North?

Most roofs were not designed for solar. If your best available roof faces east or west, you are not out of luck — but you should know what it costs you.

East-facing panels lose 15-20% of total daily output compared to north-facing — but they produce more in the morning. West-facing panels lose a similar amount but produce more in the afternoon. This is not always a disadvantage.

If your household uses most electricity in the morning (borehole pump at 7 AM, breakfast cooking, geyser heating), east-facing panels actually serve you better during those peak-demand hours. The total daily kWh is lower, but more of it arrives when you need it.

The East-West Split

Some installers split panels across east and west roof faces. This produces a flatter generation curve — less peak output at midday but more consistent production from morning through afternoon.

The east-west split works particularly well for households that are home all day or that want to maximise self-consumption without batteries. The generation curve better matches a typical household's usage pattern.

Tilt Angle: Finding the Right Pitch

Tilt angle is how far your panels are angled from horizontal. In Zimbabwe, the optimal tilt for annual production is approximately your latitude minus 10 degrees.

Zimbabwe spans from about 15 degrees S (Chirundu) to 22 degrees S (Beitbridge). That puts the optimal tilt range at roughly:

Most residential roofs in Zimbabwe already have a pitch between 15 and 25 degrees — conveniently close to optimal. If your panels go directly onto an existing roof, the roof pitch is your tilt angle and it is probably fine.

Seasonal Considerations

The optimal tilt depends on which season matters more to you:

• Steeper tilt (20-25 degrees): Better dry-season (winter) output when the sun is lower in the sky. Also better for self-cleaning in rain.
• Flatter tilt (5-10 degrees): Better wet-season (summer) output when the sun is more overhead.
• Compromise (10-20 degrees): Balanced annual production. This is the default recommendation.

For most hybrid systems that still have the grid as backup, optimising for annual production (the compromise tilt) makes the most sense. For off-grid systems that need to survive winter with no grid fallback, a slightly steeper tilt helps.

Flat Mounting vs Tilted Mounting

If you have a flat roof or a ground mount, you have the choice between flat and tilted mounting.

Flat mounting (0-5 degrees):

• Cheaper — no tilt frames needed, panels lay flat on the surface
• Lower wind resistance
• Collects more dust (rain does not wash panels effectively when flat)
• Slightly less output overall (5-10% less than optimal tilt)

Tilted mounting (10-20 degrees):

• Better output — panels face the sun more directly
• Self-cleaning — rain washes dust off tilted panels
• Higher wind load — needs stronger mounting
• More expensive — requires tilt frames or ground-mount racking

Shading: The Silent Killer

Shading is the single most damaging factor for solar production. Even partial shade on a small portion of one panel can dramatically reduce the output of an entire string.

Why Shading Is So Devastating

In a series-wired string, current must flow through every panel. If one panel is shaded, it produces less current — and because the string current is limited by the weakest panel, the entire string drops to match. One shaded panel in a string of 6 can reduce the whole string's output by 30-50%.

Modern panels have bypass diodes that help — they allow current to "skip" shaded cell groups within a panel. But even with bypass diodes, partial shading causes significant losses.

Common Shade Sources in Zimbabwe

• Trees — the most common problem, especially deciduous trees that grow new branches seasonally
• Neighbouring buildings — a two-storey house next door can cast shadows across your roof, particularly in winter when the sun is lower
• Water tanks — JoJo tanks on rooftops cast long shadows in the morning and afternoon
• Satellite dishes and TV aerials — small but can shade a critical cell group
• Chimneys and roof features — cast moving shadows throughout the day
• New construction — a neighbour builds upward and suddenly your panels are in shadow

How to Assess Shading

Check your proposed panel location at three times on a sunny day:

Do this check in winter (June/July) when the sun is lowest and shadows are longest. A spot that is shade-free in December might have significant shadow in June.

Ground Mount vs Roof Mount

Most residential systems in Zimbabwe go on the roof, but ground mounting is worth considering if you have the yard space.

Roof Mount Advantages

• No yard space used
• Panels are higher and less likely to be shaded by walls and fences
• Shorter cable runs to the inverter (typically in the garage below)
• Panels are out of reach of children, animals, and theft

Ground Mount Advantages

• Optimal orientation — you choose the exact direction and tilt, not limited by roof angle
• Easier maintenance — cleaning, inspection, and repairs at ground level
• No roof penetrations — no risk of leaks from mounting bolts
• Better airflow — panels on open frames run cooler than panels flat on a roof

Ground Mount Considerations for Zimbabwe

• Security — ground-level panels are more accessible for theft; consider fencing
• Dust — ground-level panels collect more dust from foot traffic and wind
• Flooding — ensure panels are elevated if your yard floods in the wet season
• Animals — dogs, chickens, and livestock can damage cables or scratch panels

Putting It All Together

The ideal panel positioning for a Zimbabwean home:

1. Face true north (or as close as your roof allows)
2. Tilt at 10-20 degrees (your roof pitch is probably close enough)
3. Zero shading between 9 AM and 3 PM, checked in winter
4. Clean panels — tilted enough for rain to wash them, or cleaned monthly in the dry season
5. Consistent orientation — all panels in a string facing the same direction at the same tilt

If your roof forces compromises, use the SolMate orientation tool to quantify exactly how much output you are giving up. Sometimes a 15% loss from a non-ideal direction is perfectly acceptable. The best solar system is the one that is installed well on the roof you have, not the theoretical perfect system that never gets built.