The Art of Heatmaps: Designing Effective Tools for Transmission Planning

The energy industry is at a crossroads. FERC Order 2023-A drives a critical shift in how utilities and RTOs/ISOs manage interconnection data. With transparency and efficiency as key priorities, heatmaps have become indispensable tools for transmission planners.

But creating effective heatmaps isn’t just about visualizing data—it’s about designing intuitive, functional tools that empower users to make smarter decisions. In this post, we’ll explore the key elements of heatmap design and functionality that make them indispensable for modern transmission planning.

Why Thoughtful Heatmap Design Matters

Heat maps have become central to interconnection workflows, offering transmission planners an efficient way to assess capacity, identify bottlenecks, and ensure compliance with FERC mandates. However, poor design can hinder these benefits, leading to:

• Misinterpretation of critical data.
• Frustration among users, especially developers and stakeholders.
• Inefficient planning processes.

To ensure heat maps fulfill their potential, utilities must focus on design principles that prioritize clarity, usability, and actionable insights.

Key Elements of Heatmap Design

1. Color Coding: The Power of Gradients

• Why It’s Important: Colors are the first thing users notice, and they should intuitively convey grid conditions.
• Best Practices:
  • Use gradients that transition from blue (available capacity) to red (congested).
  • Ensure smooth transitions to highlight subtle capacity variations.
  • Align color schemes with corporate branding to maintain consistency.
• Example in Action: Southern Company adopted raster (interpolated) heatmaps with tailored gradients to visualize capacity across their region, enhancing decision-making for stakeholders​​.

1. Interactivity: Engaging Users with Actionable Features

• Dynamic Data Tips: Hover-over functionality displays precise capacity information, aiding quick decision-making.
• Voltage-Level Toggles: Users can switch between kV levels to focus on relevant capacity for their projects.
• Year-Based Capacity Projections: Dropdowns allow developers to view grid capacity for specific future years, supporting long-term planning.

These interactive elements transform static point maps into powerful planning tools that help stakeholders customize their analysis​​.

1. Decluttering: Simplicity Drives Clarity

Heat maps must avoid overwhelming users with excessive data.

• Solution: Introduce zoom-level visibility controls that display points of interest (POIs) only when users zoom in to a certain level.
• Impact: This ensures clarity while maintaining access to detailed information when needed.

Base maps should also strike a balance—providing essential geographic context without overshadowing the heat map data.

Integrating Functionality for Advanced Planning

1. Before-and-After Views

Toggle features allow users to visualize grid conditions before and after a megawatt injection.

• Why It Matters: These visual cues simplify bottleneck identification and help understand the scope of required upgrades​​.

1. Scenario Analysis

Evaluate grid performance under different conditions, such as summer peak loads or winter demand.

• Why It Matters: Planners can proactively address grid vulnerabilities by testing various scenarios enhancing resilience.

1. Queue Data and Existing Generation Overlays

Overlaying current interconnection activity or existing generation onto heat maps helps users understand project impacts near specific points of interest.

• Why It Matters: This empowers developers with automated data insights into potential project challenges and opportunities​.

A Brief Note on UX in Heatmaps

User experience (UX) is the linchpin of effective heat map design. Intuitive interfaces, clear navigation, and actionable visualizations ensure users can derive maximum value from the data presented. Utilities can reduce the learning curve and increase adoption among diverse stakeholders by focusing on usability. (We’ll explore UX in heat maps more deeply in a future post!)

The ROI of Well-Designed Heatmaps

When thoughtfully designed, heatmaps deliver measurable benefits:

• Time Savings: Faster analysis interactive features and an intuitive interface, reducing manual effort and improving efficiency.
• Enhanced Collaboration: Clear, professional looking visualizations align stakeholders and streamline communication.
• Compliance Confidence: Tools designed with FERC requirements in mind provide peace of mind while ensuring usability​.

Conclusion

Heatmaps are more than visualization tools—by combining essential geographic information, they’re a cornerstone of modern transmission planning. Utilities can turn complex grid data into actionable insights that drive better decision-making by prioritizing thoughtful design and advanced functionality.

Are you ready to design better heatmaps? CartoVista’s cutting-edge platform combines intuitive design with powerful functionality, helping utilities meet compliance mandates and prepare for future grid demands.