Proportional Flow Widths
Link widths automatically scale to reflect flow values, so the biggest energy streams are instantly visible. No manual resizing needed.
Chart & Visualization Tools
Energy Flow Diagrams, Instantly
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.
Features
Everything You Need in an Energy Flow Diagram Maker
Purpose-built Sankey controls for energy systems — not a generic chart tool.
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.
Data input
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
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.
<2 minTime to first diagram
UnlimitedFlow nodes supported
12+Languages supported
10k+Charts created
PNG + SVGExport formats
Workflow
How to Make an Energy Flow Diagram
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.
Add Your Flow Links
Connect the nodes by specifying a source, a target, and a numeric flow value. Link width will scale automatically.
Customize the Layout
Adjust labels, colors, spacing, and opacity until the diagram communicates your energy story clearly.
Export and Share
Download a high-resolution image or copy the embed code to drop your energy flow diagram into any report or presentation.
Use cases
Who Uses This Energy Flow Diagram Maker
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
Carbon Circular Flow Sankey: See Where Carbon Goessankey
Visualize your carbon circular flow instantly. Spot emissions, recycling, and sequestration hotspots to improve ESG reporting and cut footprint fast.
Sankey Diagram Template - Map Flows ClearlysankeyStart with a blank Sankey template to map energy, budget, or process flows. Customize nodes, links, and colors instantly - no design skills needed.
Energy Flow Sankey Diagram TemplatesankeyVisualize energy sources, generation, and consumption with this free Sankey diagram template. Track flows from coal, gas, and renewables to end sectors.
Water Flow Sankey Diagram TemplatesankeyMap the full water cycle — from rainfall and snowmelt to treatment plants, residential use, and beyond — with this free Sankey diagram template.
Supply Chain Sankey Diagram TemplatesankeyVisualize your supply chain flows from raw materials to end consumers with this free Sankey diagram template. Track product movement and returns.
Blank Sankey Diagram TemplatesankeyStart with a blank Sankey diagram template to visualize revenue flows, budgets, and processes. Free, customizable, and AI-powered. No account needed.
Related Tools
Create similar charts with these tools
Flow Diagram Makersankey
Build stunning Sankey flow diagrams in minutes. Visualize energy, budget, and data flows with our free AI-powered flow diagram maker. No design skills needed.
Sankey Diagram MakersankeyCreate stunning Sankey diagrams in minutes. Visualize flows, energy transfers, and resource allocation with our free AI-powered Sankey diagram generator.
Sankey Diagrams Without ExcelsankeySkip the Excel workarounds. Build a Sankey diagram in seconds with AI. Visualize flows, budgets, and processes — free, no sign-up needed. No plugins.
Sankey Diagrams, Built InstantlysankeyBuild interactive Sankey diagrams in seconds. Visualize energy flows, budget allocations, and process data with our free AI-powered Sankey diagram maker.
Comparison
Why Use MakeCharts Over Manual Tools?
Building Sankey diagrams by hand in spreadsheets or design software is slow and error-prone.
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
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
FAQ
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.
Can I export my energy flow diagram for a report or presentation?
Yes. Download your finished Sankey diagram as a high-resolution PNG or vector SVG file. Both formats work in PowerPoint, Google Slides, Word, PDF reports, and print-ready publications. Embed codes for live interactive diagrams are available on Plus and higher plans.
How is this different from a generic Sankey diagram maker?
MakeCharts is purpose-built for ease of use: live preview, plain-language AI generation, proportional auto-scaling link widths, and one-click export. You do not need to write code, install software, or learn a complex charting library to produce a professional energy flow diagram.
Can I customize the colors and layout of my Sankey diagram?
Yes. Assign custom colors to each node, choose between node-based and gradient color schemes, adjust node width and spacing, control link opacity, and set font sizes for labels and flow values — all from the simple configuration panel.
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
Start now
Build Your Energy Flow Diagram Now
No signup. No install. A professional Sankey diagram in under two minutes.
- Free Sankey diagram builder
- AI generation from plain language
- PNG and SVG export
- Live preview as you edit
- No account required
No account required. Free to start.