Heat Map Analysis

Heat Map Analysis in solar design refers to the visual representation of irradiance, shading, temperature, or performance values across a roof surface, array layout, or site model. Heat maps use color gradients—from cool blues to warm reds—to highlight areas of high or low productivity, shading intensity, thermal stress, or energy yield.

This visualization method helps solar designers, EPC teams, engineers, and installers quickly understand how environmental and geometric factors impact PV system performance. Heat maps are essential in modern solar workflows and are commonly integrated into platforms like Solar Designing, shading engines such as Shadow Analysis, and production modeling tools.

Key Takeaways

Heat Map Analysis visualizes solar performance metrics using color gradients.
It identifies shading, irradiance, thermal, and energy yield variations across surfaces.
Essential for optimizing solar layout, module placement, and production modeling.
Used in residential, commercial, and utility-scale solar design workflows.
Seamlessly integrates with tools like Solar Designing and Shadow Analysis for better accuracy.

What Is Heat Map Analysis?

Heat Map Analysis is a graphical method used to interpret spatial solar performance metrics across a surface. Each color represents a specific range of irradiance, shading level, temperature, or energy production.

Solar professionals rely on heat maps to:

Identify high-shading zones
Optimize panel placement
Compare POA irradiance differences across roof planes
Evaluate thermal performance risks
Analyze year-round sun-path impacts
Determine which zones deliver maximum kWh output

Heat Map Analysis converts raw modeling data into an intuitive visual format, making complex engineering insights immediately understandable.

Related concepts include Shading Analysis, POA Irradiance, and Solar Layout Optimization.

How Heat Map Analysis Works

1. Surface Geometry Is Identified

Roof planes, ground surfaces, or 3D models are mapped.

2. Simulation Data Is Calculated

Common heat map metrics include:

Irradiance (annual or monthly)
Shade percentage
Thermal accumulation
Energy yield (kWh/m²)

3. Values Are Assigned to a Color Gradient

Example:

Dark red → highest irradiance or highest temperature
Blue → lowest irradiance or complete shading

4. Heat Map Overlays the Design Surface

Panels are placed around—or optimized for—these gradients.

5. Designers Optimize Layout Using Heat Map Feedback

This may include:

Adjusting tilt
Avoiding shaded roof areas
Changing module types
Increasing spacing to reduce row-to-row shading

SurgePV's heat map engine integrates shading, irradiance, and 3D modeling to make these decisions immediate and accurate.

Types / Variants of Heat Maps in Solar

1. Irradiance Heat Map

Shows sunlight intensity across the roof or site.

2. Shading Heat Map

Highlights areas with frequent or seasonal shading.

3. Thermal Heat Map

Shows module temperature variations—important for performance and degradation.

4. Energy Yield Heat Map

Represents kWh/m² performance potential.

5. POA (Plane of Array) Heat Map

Colorizes POA irradiance over time—see POA Irradiance.

6. 3D Heat Map

Rendered over 3D surfaces, often used in complex roof modeling.

How It’s Measured

Heat maps represent one or more engineering metrics:

Irradiance (W/m² or kWh/m²-year)

Used to determine productivity potential.

Shading (% of annual time shaded)

Directly tied to system losses.

Temperature (°C)

Affects module efficiency—hotter zones generate less power.

Yield (kWh/m²)

Used to estimate output per roof segment.

Solar Access (%)

Measures how much usable sunlight reaches a surface.

Measurements typically come from simulations using:

Irradiance engines
Sun-path modeling
Shading algorithms
Thermal models

Typical Values / Ranges

Heat maps help identify these zone boundaries visually.

Practical Guidance for Solar Designers & Installers

1. Avoid shaded zones shown in the heat map

Even moderate shading can reduce production by 20–40%.

2. Optimize module placement based on irradiance gradients

High-irradiance areas should receive the best modules or highest density.

3. Evaluate row spacing and tilt decisions

Heat maps reveal inter-row shading issues early.

4. Identify thermal hotspots

Use heat maps to reduce long-term degradation and performance loss.

5. Use heat maps for client education

Customers understand visuals better than raw numbers—use them in proposals via Solar Proposal Tools.

6. Pair Heat Map Analysis with design tools

Especially:

7. Use heat maps to compare design variants

Helps choose between:

Different tilts
Module types
Row spacing setups
Sub-array orientations

Heat Map Analysis is essential for maximizing system performance before installation.

Real-World Examples

1. Residential Rooftop

A heat map reveals heavy afternoon shading on the west side of the roof.

The designer shifts module placement to the south-facing section, improving annual kWh output by 18%.

2. Commercial Flat Roof

An irradiance heat map identifies cooler, high-yield zones away from HVAC equipment.

These zones are prioritized for module layout.

3. Ground-Mount Utility Project

A terrain-based heat map shows slope-driven shading variations.

Row heights and spacing are adjusted to maximize energy yield.