Energy Flow Diagrams, Instantly
Turn raw energy data into clear Sankey flow diagrams in seconds.
Map where energy enters, flows, transforms, and is lost — all in one visual. Our AI-powered energy flow diagram maker builds publication-ready Sankey charts from your data.
Everything You Need in an Energy Flow Diagram Maker
Purpose-built Sankey controls for energy systems — not a generic chart tool.
Proportional Flow Widths
Link widths automatically scale to reflect flow values, so the biggest energy streams are instantly visible. No manual resizing needed.
Custom Node Colors
Assign distinct colors to each energy source, process, or loss node to make your diagram immediately legible at a glance.
AI-Powered Generation
Describe your energy system in plain language and let the AI build the Sankey structure, nodes, and flow values for you.
Live Preview
Every edit — adding a node, changing a flow value, adjusting spacing — updates the diagram in real time as you type.
Flexible Layout Controls
Adjust node width, spacing, link opacity, and label font size to produce a clean, readable energy flow diagram for any audience.
No Install, No Signup
Open the energy flow diagram maker in your browser and start building immediately — nothing to download or configure.
Add Your Energy Data Any Way You Like
Type It In
Enter node names and flow values directly into the editor — no formatting required.
Paste From Spreadsheet
Copy rows from Excel or Google Sheets and paste them straight into the flow editor.
Upload a File
Import CSV or Excel data files directly for large or complex energy system models (Pro).
Describe With AI
Tell the AI your energy system in plain language and get a fully built diagram in seconds.
Share Your Energy Flow Diagram Anywhere
Download as Image
Export high-resolution PNG or SVG files ready for reports, audits, and presentations.
Share a Link
Get a shareable URL to send your energy flow diagram to colleagues or clients instantly.
Embed on Your Site
Add a live, interactive Sankey diagram to any webpage with a single embed code (Plus+).
Use in Slides
Drop the downloaded image directly into PowerPoint, Google Slides, or Keynote decks.
About MakeCharts Energy Flow Diagram Maker
MakeCharts is a free online chart maker built for clarity and speed. The energy flow diagram maker uses Sankey chart technology to turn raw flow data into proportional, publication-ready visuals. No setup, no design skills, no waiting.
- ✓Powered by AI that understands energy systems and flow language
- ✓Sankey diagrams with auto-scaling link widths and live preview
- ✓Part of a 30+ chart library covering flows, comparisons, and more
- ✓Used by engineers, sustainability teams, educators, and researchers
- ✓Free to use — upgrade only when you need more AI charts or advanced features
Built for Speed and Clarity
How to Make an Energy Flow Diagram
From raw data to a polished Sankey diagram in four simple steps.
Define Your Nodes
Add each energy source, conversion stage, end use, and loss as a named node. Give each one a distinct color for clarity.
Nodes: 'Natural Gas', 'Boiler', 'Space Heating', 'Flue Loss'
Add Your Flow Links
Connect the nodes by specifying a source, a target, and a numeric flow value. Link width will scale automatically.
Natural Gas → Boiler: 100 | Boiler → Space Heating: 72 | Boiler → Flue Loss: 28
Customize the Layout
Adjust labels, colors, spacing, and opacity until the diagram communicates your energy story clearly.
Increase node spacing, show flow values, switch to gradient color scheme
Export and Share
Download a high-resolution image or copy the embed code to drop your energy flow diagram into any report or presentation.
Export PNG for the audit report, embed link for the internal dashboard
Who Uses This Energy Flow Diagram Maker
From facility audits to research papers — Sankey diagrams make energy data unmissable.
Visualize Building Energy Losses
Show exactly where a facility loses energy — HVAC inefficiencies, envelope losses, plug loads — so engineers and clients can prioritize retrofits instantly.
Communicate Carbon and Energy Strategy
Turn complex Scope 1, 2, and 3 energy data into a single, compelling Sankey diagram stakeholders can understand in seconds.
Illustrate Energy System Models
Create clear, publication-quality Sankey diagrams to support research papers, thesis chapters, and conference presentations on energy systems.
Identify Process Inefficiencies
Map energy inputs, outputs, and waste heat across production lines to find quick wins that cut costs and reduce emissions.
Templates
Start with professionally designed templates
Why Use MakeCharts Over Manual Tools?
Building Sankey diagrams by hand in spreadsheets or design software is slow and error-prone.
Spreadsheets & Design Tools
- ✗Hours spent building flow geometry manually
- ✗Link widths must be calculated and drawn by hand
- ✗One data change forces a full rebuild
- ✗No AI to suggest structure or fill values
- ✗Requires design skills to look professional
- ✗Hard to collaborate or share interactively
MakeCharts Energy Flow Maker
- ✓Diagram ready in under two minutes
- ✓Flow widths scale automatically to your values
- ✓Live preview updates instantly on every edit
- ✓AI generates the full Sankey from a description
- ✓Professional output with zero design experience
- ✓Share via link, image, or embed code
Frequently Asked Questions
What is an energy flow diagram?
An energy flow diagram — also called a Sankey diagram — uses proportional-width arrows to show how energy moves through a system. The wider the flow band, the more energy it represents. They are widely used in energy audits, engineering reports, and sustainability disclosures to make losses and efficiencies immediately visible.
How does this energy flow diagram maker work?
You define nodes (energy sources, processes, end uses, losses) and links (the flows between them with numeric values). The tool renders a Sankey diagram where link widths automatically scale to your data. You can also use the AI assistant — just describe your energy system and it builds the diagram for you.
Is this energy flow diagram maker free?
Yes. The core Sankey diagram builder is completely free with no sign-up required. You get free AI credits on every account to try AI-powered generation. Paid plans unlock more AI charts per month, file upload, embed codes, and priority support.
Can I make a Sankey diagram for energy without any data?
Absolutely. Use the AI prompt box to describe your energy system in plain language — for example, 'solar panels providing 200 kWh, 80 to the grid, 60 to heating, 60 lost' — and the AI will build a fully structured Sankey diagram with realistic nodes and flow values.
What kinds of energy flow diagrams can I create?
You can model any energy system: building energy balances, industrial process flows, national energy accounts, HVAC efficiency maps, renewable energy mixes, carbon and fuel flow diagrams, and more. Any system with sources, conversions, end uses, and losses maps cleanly to a Sankey.
Made for Everyone
- ✓No engineering or design background required to build a clear energy flow diagram
- ✓Available in 12+ languages so global teams can use it in their own language
- ✓Works on desktop, tablet, and mobile browsers without any installation
- ✓Plain-language AI means non-technical stakeholders can create diagrams too
- ✓Free tier ensures students, researchers, and small businesses are never locked out
Your Data, Your Control
- •Your energy data is used only to render your diagram — we do not sell or share it
- •No account required to create and download a Sankey diagram
- •You decide what to share: download locally or generate a shareable link on your terms
- •Delete your account and associated data at any time from your account settings
- •We do not store uploaded files beyond your active session without your permission
Build Your Energy Flow Diagram Now
No signup. No install. A professional Sankey diagram in under two minutes.