GUIDEBOOK · CEA v4.0

Visualisation

Visualisation

Visualisation features create charts and plots to present CEA results. These tools generate publication-quality graphics for energy demand, emissions, solar potential, comfort analysis, and optimisation results.

Plot - Building Energy Demand

Overview

Creates bar charts of building energy demand results, showing heating, cooling, electricity, and hot water demand for selected buildings. This is the primary visualisation for energy demand forecasting results.

When to Use

• After completing Energy Demand Part 2
• Presenting building energy performance
• Comparing energy demand across buildings
• Supporting energy reports and presentations

What It Plots

Energy Services:

• Space heating (Qhs)
• Space cooling (Qcs)
• Electricity (E) - appliances, lighting, auxiliaries
• Domestic hot water (Qww)

Chart Types Available:

1. Annual demand - Total MWh/year per building (stacked bar)
2. Energy intensity - kWh/m²/year per building (normalised)
3. Peak loads - Maximum kW per building
4. Time series - Hourly demand profiles (line charts)
5. Monthly aggregation - Seasonal patterns

Prerequisites

• Energy Demand Part 2 completed
• Total demand file exists

Key Parameters

How to Use

1. Complete Energy Demand Part 2

2. Run plot generation:

   • Navigate to Visualisation
   • Select Plot - Building Energy Demand
   • Choose chart type (start with “Annual demand”)
   • Select buildings (or use “All”)
   • Choose whether to stack or group energy services
   • Click Run

3. View results:

   • Charts saved to {scenario}/outputs/plots/demand/
   • Interactive HTML plots (open in browser)
   • Static PNG/PDF (for presentations)

Chart Interpretation

Annual Demand Bar Chart:

• Height = total energy (MWh/year)
• Colors = energy services (heating, cooling, electricity, DHW)
• Taller bars = higher energy consumers
• Color distribution shows energy mix

Energy Intensity:

• Normalises by floor area (kWh/m²/year)
• Allows comparison regardless of building size
• Typical ranges:
  • Low-energy buildings: 50-100 kWh/m²/year total
  • Standard buildings: 100-200 kWh/m²/year
  • Old/inefficient: >200 kWh/m²/year

Time Series:

• Shows hourly variation over year
• Identify peak demand periods
• Assess load diversity
• Support system sizing

Customisation Options

• Colors: Customise color scheme for energy services
• Sorting: Sort buildings by total demand, name, or type
• Labels: Show/hide data labels on bars
• Legend: Position and format
• Export format: HTML (interactive), PNG, PDF, SVG

Tips

• Start with annual demand: Best overview of results
• Use intensity for comparisons: Fairer comparison across building sizes
• Filter by type: Group similar buildings for clearer insights
• Time series for validation: Check if patterns make sense

Troubleshooting

Issue: No plots generated

• Solution: Ensure Energy Demand Part 2 completed successfully
• Solution: Check Total_demand.csv exists

Issue: Charts show unexpected values

• Solution: Validate demand calculation results first
• Solution: Check units (MWh vs kWh)

Plot - Final Energy

See Final Energy > Plot - Final Energy for full documentation.

Bar charts of final energy consumption by carrier (grid, gas, oil, coal, wood) for buildings and plants under a what-if scenario.

Plot - Lifecycle Emissions

See Emissions > Plot - Lifecycle Emissions for full documentation.

Stacked bar charts showing total lifecycle emissions per building (embodied + operational + biogenic + solar offsets). Title includes the lifecycle year range.

Plot - Emission Timeline

See Emissions > Plot - Emission Timeline for full documentation.

Cumulative stacked area chart showing how district emissions evolve from construction through demolition.

Plot - Operational Emissions

See Emissions > Plot - Operational Emissions for full documentation.

Bar charts of operational emissions by service or energy carrier, with solar offset as negative bars.

Plot - Cost Sankey

See System Costs > Plot - Cost Sankey for full documentation.

Sankey diagram showing cost flows from components through services to total costs, with annualised or total CAPEX views.

Plot - Heat Rejection

See Heat Rejection > Plot - Heat Rejection for full documentation.

Bar charts of waste heat rejected to the environment by buildings and district plants.

Plot - Solar Technology

Overview

Creates bar charts of solar energy technology potential (PV, PVT, solar collectors), showing electricity and heat generation capacity for buildings.

When to Use

• After running renewable energy assessments
• Presenting solar potential results
• Supporting solar investment decisions
• Comparing solar technologies

What It Plots

Solar Technologies:

• PV: Electricity generation (MWh/year, kWp capacity)
• PVT: Electricity + heat generation
• Solar collectors: Heat generation (MWh/year)

Chart Types:

1. Annual generation - Total MWh/year by technology
2. Installed capacity - kWp (PV/PVT) or m² (SC)
3. Technology comparison - PV vs PVT vs SC side-by-side
4. Specific yield - kWh/kWp/year or kWh/m²/year

Prerequisites

• At least one solar technology assessment completed:
  • Photovoltaic Panels
  • PVT Panels
  • Solar Collectors

How to Use

1. Complete solar assessments (PV, PVT, and/or SC)

2. Generate plots:

   • Navigate to Visualisation
   • Select Plot - Solar Technology
   • Choose technologies to include
   • Select chart type
   • Click Run

3. Outputs: {scenario}/outputs/plots/solar/

Chart Interpretation

Annual Generation:

• Compares total output by technology
• PV: Electricity only
• PVT: Electricity + heat (show both)
• SC: Heat only

Comparison Across Buildings:

• Identifies buildings with best solar potential
• Accounts for shading, orientation, available area

Technology Trade-offs:

• PV: Maximum electricity, no heat
• PVT: Balanced electricity + heat, lower electrical efficiency
• SC: Maximum heat, no electricity

Tips

• Normalise by area: Use kWh/m² for fair comparison
• Show both capacity and yield: Capacity = size, yield = performance
• Highlight best performers: Identify buildings for priority installation

Plot - Building Comfort Chart

Overview

Plots comfort and discomfort hours for buildings based on thermal comfort analysis from energy demand calculations. Shows when indoor conditions meet or fail to meet comfort criteria.

When to Use

• After Energy Demand calculation
• Assessing indoor environmental quality
• Evaluating HVAC system performance
• Supporting comfort-based design decisions

What It Plots

Comfort Metrics:

• Total comfort hours (hours/year within setpoint ranges)
• Discomfort hours (hours/year outside ranges)
  • Too hot
  • Too cold
• By building and by zone (if multi-zone)

Comfort Standards:

• Based on setpoints in comfort.xlsx
• Typically ASHRAE 55 or EN 15251 criteria
• Adaptive comfort models (if configured)

Prerequisites

• Energy Demand Part 2 completed
• Comfort setpoints defined in comfort.xlsx

How to Use

1. Complete Energy Demand calculation

2. Generate comfort plots:

   • Navigate to Visualisation
   • Select Plot - Building Comfort Chart
   • Select buildings
   • Click Run

3. Outputs: {scenario}/outputs/plots/comfort/

Chart Types

Annual Comfort Hours:

• Stacked bar showing comfort/discomfort split
• Goal: Minimise discomfort hours

Discomfort Breakdown:

• Too hot vs too cold
• Seasonal patterns

Comfort vs Outdoor Temperature:

• Scatter plots showing indoor-outdoor relationship

Interpretation

Acceptable Discomfort:

• Category I (best): <10% discomfort (< 876 hours)
• Category II (standard): 10-20% discomfort (876-1,752 hours)
• Category III (acceptable): 20-30% discomfort (1,752-2,628 hours)

• 30% discomfort: Unacceptable

Typical Patterns:

• Free-running buildings: More discomfort but acceptable
• Fully conditioned: Minimal discomfort, high energy use
• Balance: Moderate comfort, moderate energy

Tips

• Compare comfort vs energy: High comfort often means high energy
• Seasonal analysis: Identify summer overheating or winter underheating
• Validate HVAC sizing: Excessive discomfort suggests undersized systems

Plot - Pareto Front

Overview

Plots Pareto frontiers from optimisation results, visualising trade-offs between competing objectives (cost, emissions, energy).

When to Use

• After running Supply System Optimisation
• Presenting optimisation results
• Supporting multi-objective decision-making
• Showing cost-carbon trade-offs

What It Plots

Optimisation Objectives:

• Typically 2D or 3D scatter plots
• X-axis: Total annualised cost (CHF/year or $/year)
• Y-axis: Total GHG emissions (kgCO₂e/year)
• Optionally Z-axis: Primary energy (MWh/year)

Points on Chart:

• Pareto optimal solutions: Non-dominated solutions (on frontier)
• Dominated solutions: Worse on all objectives (not shown or greyed)
• Reference solutions: Baseline, current state

Prerequisites

• Building-scale or District-scale optimisation completed

Key Parameters

How to Use

1. Complete optimisation (building or district scale)

2. Generate Pareto plot:

   • Navigate to Visualisation
   • Select Plot - Pareto Front
   • Choose objectives for axes
   • Optionally highlight key solutions
   • Click Run

3. Outputs: {scenario}/outputs/plots/optimisation/pareto_front/

Chart Interpretation

Pareto Frontier:

• Lower-left corner: Best solutions (low cost, low emissions)
• Horizontal movement: Cost changes with minimal emission change
• Vertical movement: Emission changes with minimal cost change
• No solution dominates another on frontier

Key Points on Frontier:

1. Min cost solution: Cheapest option (often high emissions)
2. Min emissions solution: Cleanest option (often expensive)
3. Knee point: Best compromise (balanced cost and emissions)

Decision Making:

• Choose solution based on priorities (budget, climate goals)
• Trade-off rate: EUR per ton CO₂ saved
• Carbon price implications

Customisation

• Color by technology: Show which technologies appear in solutions
• Size by objective: Third objective as marker size
• Annotate: Label key solutions

Tips

• Show current state: Add reference point for context
• Calculate trade-off rate: Cost increase per ton CO₂ reduction
• Interactive plots: HTML allows hovering to see solution details
• Multiple scenarios: Overlay Pareto fronts to compare

Common Visualisation Workflow

Standard Visualisation Sequence

After completing CEA analyses:

1. Energy Demand Plots:

   • Plot - Building Energy Demand (annual and intensity)
   • Validate results before proceeding

2. Life Cycle Analysis Plots (per what-if scenario):

   • Plot - Final Energy (carrier breakdown)
   • Plot - Lifecycle Emissions (full lifecycle carbon)
   • Plot - Emission Timeline (cumulative trajectory)
   • Plot - Operational Emissions (operational carbon)
   • Plot - Cost Sankey (cost flow diagram)
   • Plot - Heat Rejection (waste heat)

3. Renewable Energy Plots:

   • Plot - Solar Technology (if solar assessments done)

4. Comfort Plots (optional):

   • Plot - Building Comfort Chart (verify thermal comfort)

5. Optimisation Plots (if optimisation done):

   • Plot - Pareto Front (show trade-offs and optimal solutions)

Creating Presentation Packages

For Reports:

• Export as PNG or PDF (300 dpi)
• Use consistent color schemes
• Include data tables with charts

For Presentations:

• Export as SVG for scaling
• Use interactive HTML for workshops
• Highlight key findings with annotations

For Publications:

• Export vector formats (SVG, PDF)
• Follow journal style guidelines
• Provide source data

Visualisation Best Practices

Chart Design

• Clear titles: Describe what is shown
• Axis labels: Include units
• Legend: Essential for multi-series charts
• Colors: Use colorblind-friendly palettes
• Annotations: Highlight key findings

Data Presentation

• Normalise when comparing: Use intensity (per m² or per capita)
• Sort logically: By value, name, or type
• Filter for clarity: Don’t show too many buildings (>20 becomes cluttered)
• Aggregate when needed: Group by building type if many buildings

Storytelling with Charts

1. Start with overview: Total demand, total emissions
2. Break down by component: Which services dominate?
3. Compare across buildings: Identify outliers and patterns
4. Show time dimension: How do patterns vary over time?
5. Present solutions: If optimisation done, show improvements

Customising Plots

Configuration Files

Advanced users can customise plot appearance via configuration files:

• Color schemes
• Chart dimensions
• Font sizes
• Export formats

See CEA documentation for details on plot configuration.

Post-Processing

For publication-quality figures:

1. Export as SVG
2. Edit in Inkscape or Adobe Illustrator
3. Adjust fonts, colors, labels as needed
4. Export to required format

Related Features

• Energy Demand Forecasting - Provides demand data
• Life Cycle Analysis - Provides emissions data
• Renewable Energy - Provides solar generation data
• Supply System Optimisation - Provides Pareto frontier data
• Export Results to CSV - Export data for custom plots

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