CCA Online Tools

Dynamic Sun Elevation Configuration

🌍 The Problem

Fixed sun elevation thresholds don’t work optimally throughout the year due to Earth’s axial tilt and orbital motion:

Winter Issues:

Summer Issues:

Daylight Saving Time:

✨ The Solution

Template sensors with sinusoidal interpolation automatically adapt thresholds based on the current date, matching the Earth’s actual solar cycle.

How the Sensors Work

The sensors provide dynamic threshold values that change throughout the year:

Example scenario (Berlin, 52°N):

Visual Comparison

Annual Threshold Curve

The graph above shows how the dynamic sun elevation threshold changes throughout the year, comparing sinusoidal interpolation (recommended) with linear interpolation.

ASCII version (click to expand) ``` Sun Elevation Threshold Throughout Year (50°N) 6° ┤╲ ╱ │ ╲ ╱ 4° ┤ ╲ ╲─────────────────────────╱ ╱ │ ╲ ╲ ╱ ╱ 2° ┤ ╲ ╲ ← Spring/Autumn: ╱ ╱ Linear │ ╲ ╲ Sine changes ╱ ╱─╲ 0° ┤ ╲ ╲ faster! ╱ ╱ ╲ │ ╲ ╲ ╱╱ ╲ -2° ┤ ╲ ╰─Sine curve─╯╱ ╲ │ ╲ ╱ ╲ -4° ┼──┬────┬──┴─────────────────┴────┬────┬─── Jan Mar May Jul Sep Nov Jan ↑ ↑ Equinox Equinox (faster) (faster) Solstice → Jun/Dec ← Solstice (slower) ```

Why Sine is Better:

🚀 Quick Setup (5 Minutes)

Step 1: Add Template Sensors

Add this to your configuration.yaml or create a new file in packages/:

template:
  - trigger:
      - trigger: time
        at: "00:01:00"
      - platform: event
        event_type:
          - homeassistant_started
    sensor:
      # ========================================
      # Dynamic Sun Elevation - Opening
      # ========================================
      - name: "Sun Elevation Up Dynamic"
        unique_id: sun_elevation_up_dynamic
        unit_of_measurement: "°"
        icon: mdi:weather-sunset-up
        state: >
          {% set day = now().timetuple().tm_yday %}
          {% set lat = state_attr('zone.home', 'latitude') | float(52.0) %}

          {# Reference values for 50°N #}
          {% set summer = -2.0 %}
          {% set winter = 5.0 %}

          {# Sinusoidal interpolation (physically correct) #}
          {# Day 80.75 ≈ March 21 (spring equinox) as reference #}
          {% set seasonal_factor = sin(2 * pi * (day - 80.75) / 365) %}
          {% set base = winter + (summer - winter) * (seasonal_factor + 1) / 2 %}

          {# Latitude adjustment: ±0.2° per degree from 50°N #}
          {% set adjustment = (lat - 50) * 0.2 %}
          {% set final = base + adjustment %}

          {{ final | round(1) }}

      # ========================================
      # Dynamic Sun Elevation - Closing
      # ========================================
      - name: "Sun Elevation Down Dynamic"
        unique_id: sun_elevation_down_dynamic
        unit_of_measurement: "°"
        icon: mdi:weather-sunset-down
        state: >
          {% set day = now().timetuple().tm_yday %}
          {% set lat = state_attr('zone.home', 'latitude') | float(52.0) %}

          {# Reference values for 50°N #}
          {% set summer = -1.0 %}
          {% set winter = 2.0 %}

          {# Sinusoidal interpolation (physically correct) #}
          {% set seasonal_factor = sin(2 * pi * (day - 80.75) / 365) %}
          {% set base = winter + (summer - winter) * (seasonal_factor + 1) / 2 %}

          {# Latitude adjustment #}
          {% set adjustment = (lat - 50) * 0.2 %}
          {% set final = base + adjustment %}

          {{ final | round(1) }}

Step 2: Restart Home Assistant

Settings → System → Restart

Step 3: Verify Sensors

Developer Tools → States → Search for:

Both should show numeric values (e.g., 2.3)

Step 4: Configure CCA Blueprint

In your CCA automation configuration:

  1. Navigate to Sun Elevation Settings section
  2. Find the new Dynamic Sensor fields:
    • ☀️ Sun Elevation Up Sensor (Dynamic): Select sensor.sun_elevation_up_dynamic
    • ☀️ Sun Elevation Down Sensor (Dynamic): Select sensor.sun_elevation_down_dynamic
  3. Save automation

Done! 🎉 Your covers now adapt automatically to seasons.

⚠️ Common Mistake: Inverted Values

CRITICAL: Make sure your summer and winter values are NOT inverted!

Many users initially configure these values backwards. Here’s how to verify you have them correct:

✅ Correct Configuration

Opening sensor (Sun Elevation Up Dynamic):

{% set summer = -2.0 %}  # ✅ LOWER value for summer (opens EARLIER)
{% set winter = 5.0 %}   # ✅ HIGHER value for winter (opens LATER)

Closing sensor (Sun Elevation Down Dynamic):

{% set summer = -1.0 %}  # ✅ LOWER value for summer (closes LATER)
{% set winter = 2.0 %}   # ✅ HIGHER value for winter (closes EARLIER)

❌ Common Mistake (INVERTED)

If you have this, it’s WRONG:

# Opening sensor - INVERTED (WRONG!)
{% set summer = 5.0 %}   # ❌ Summer value HIGHER than winter
{% set winter = -2.0 %}  # ❌ Winter value LOWER than summer

# Closing sensor - INVERTED (WRONG!)
{% set summer = 2.0 %}   # ❌ Summer value HIGHER than winter
{% set winter = -1.0 %}  # ❌ Winter value LOWER than summer

🧪 Quick Test

After setting up your sensors, verify the values in Developer Tools:

In Summer (June-July):

In Winter (December-January):

If your values are the opposite, your configuration is INVERTED!

🎯 Remember the Logic

📊 How It Works

Both Sensors Throughout Year

The graph above visualizes how both opening and closing sensors work together throughout the year, creating different “open window” durations in summer vs winter.

Understanding the Comparison Logic

The dynamic sensors provide threshold values that are compared with the current sun elevation:

Opening Logic (Sun Elevation Up):

Closing Logic (Sun Elevation Down):

Automatic Features

✅ Reads your latitude from zone.home automatically ✅ Calculates optimal thresholds for your location ✅ Interpolates smoothly between summer and winter values ✅ Updates daily to follow sun’s annual path ✅ No maintenance required after initial setup

Reference Values

The sensors use these baseline values for 50°N latitude (Central Europe):

Sensor Summer (Jun 21) Winter (Dec 21) Range
Opening -2.0° 5.0° 7.0° span
Closing -1.0° 2.0° 3.0° span

Automatic latitude adjustment: ±0.2° per degree difference from 50°N

Values at Different Latitudes

Latitude Comparison

The graph above shows how the opening sensor thresholds automatically adjust for different latitudes across Europe.

Location Latitude Opening Summer Opening Winter
Tromsø 🇳🇴 69.6°N 1.9° 8.9°
Stockholm 🇸🇪 59.3°N -0.1° 6.9°
Copenhagen 🇩🇰 55.7°N -0.9° 6.1°
Berlin 🇩🇪 52.5°N -1.5° 5.5°
London 🇬🇧 51.5°N -1.7° 5.3°
Paris 🇫🇷 48.9°N -2.2° 4.8°
Vienna 🇦🇹 48.2°N -2.4° 4.6°
Milan 🇮🇹 45.5°N -3.1° 3.9°
Rome 🇮🇹 41.9°N -3.8° 3.2°
Athens 🇬🇷 38.0°N -4.6° 2.4°

🔧 Customization

When to Customize

You probably DON’T need to customize if:

You SHOULD customize if:

Modify the summer and winter values to shift timing:

{# Original values #}
{% set summer = -2.0 %}
{% set winter = 5.0 %}

{# Open earlier in morning #}
{% set summer = -4.0 %}   # Lower value = earlier opening
{% set winter = 3.0 %}

{# Open later in morning #}
{% set summer = 0.0 %}   # Higher value = later opening
{% set winter = 7.0 %}

Rule of thumb: Each 1° change shifts timing by approximately 4-6 minutes.

Method 2: Adjust Latitude Factor (Advanced)

Change latitude sensitivity by modifying the 0.2 multiplier:

{# Standard (recommended) #}
{% set adjustment = (lat - 50) * 0.2 %}

{# More aggressive latitude adjustment #}
{% set adjustment = (lat - 50) * 0.3 %}

{# Less aggressive latitude adjustment #}
{% set adjustment = (lat - 50) * 0.1 %}

Method 3: Different Summer/Winter Ratios

Create asymmetric behavior:

{# Aggressive summer (very early), conservative winter #}
{% set summer = -5.0 %}
{% set winter = 3.0 %}

{# Conservative summer, aggressive winter (very late) #}
{% set summer = -1.0 %}
{% set winter = 8.0 %}

🎯 Examples by Use Case

Early Bird Setup (Opens Early)

# Opening sensor
{% set summer = -4.0 %}  # Was: -2.0
{% set winter = 3.0 %}   # Was: 5.0

# Closing sensor
{% set summer = -3.0 %}  # Was: -1.0
{% set winter = 0.0 %}   # Was: 2.0

Effect: Covers open ~30 min earlier, close ~30 min earlier

Night Owl Setup (Opens Late)

# Opening sensor
{% set summer = 0.0 %}   # Was: -2.0
{% set winter = 7.0 %}   # Was: 5.0

# Closing sensor
{% set summer = 1.0 %}   # Was: -1.0
{% set winter = 4.0 %}   # Was: 2.0

Effect: Covers open ~30 min later, close ~30 min later

Maximum Privacy (Stays Closed Longer)

# Opening sensor - very late
{% set summer = 3.0 %}
{% set winter = 10.0 %}

# Closing sensor - very early
{% set summer = 1.0 %}
{% set winter = 5.0 %}

Effect: Minimum exposure time, maximum privacy

Energy Saving (Solar Heat Gain)

# Opening sensor - early to capture morning sun
{% set summer = -5.0 %}
{% set winter = 2.0 %}

# Closing sensor - late to keep warmth inside
{% set summer = -4.0 %}
{% set winter = 0.0 %}

Effect: Opens early (solar gain), closes late (heat retention)

📐 Mathematical Background

Sine Wave Explanation

The diagram above shows how the sine function transforms the seasonal cycle into smooth threshold values.

The Sine Formula

elevation = winter + (summer - winter) × (sin(2π × (day - 80.75) / 365) + 1) / 2

Why Day 80.75?

Day 80.75 ≈ March 21 (Spring Equinox)

This is the reference point where:

Key Dates in Solar Cycle

        Dec 21 (Day 355)           Jan 1
      MAXIMUM THRESHOLD        MAXIMUM THRESHOLD
              ╲╱                      ╲╱
            ╱  ╲                    ╱  ╲
          ╱      ╲                ╱      ╲
        ╱          ╲            ╱          ╲
     ╱              ╲        ╱              ╲
Mar 21                ╲    ╱                Sep 23
(Day 80)               ╲  ╱                 (Day 266)
EQUINOX                 ╲╱                  EQUINOX
                        ╱╲
                      ╱    ╲
                    ╱        ╲
                  ╱            ╲
                ╱                ╲
              ╱                    ╲
            ╱                        ╲
          ╱                            ╲
        Jun 21 (Day 172)
     MINIMUM THRESHOLD

Note: For threshold values with summer < winter,
      the sine curve is inverted compared to sun's declination

Step-by-Step Calculation

Example: September 20 (Day 263), 52°N (Berlin), Opening sensor

# 1. Get inputs
day = 263
lat = 52.0
summer = -2.0
winter = 5.0

# 2. Calculate seasonal factor
days_from_equinox = 263 - 80.75 = 182.25
radians = 2 × π × 182.25 / 365 = 3.14 rad
sin_value = sin(3.14) ≈ 0.00
seasonal_factor = 0.00

# 3. Calculate base elevation
base = 5.0 + (-2.0 - 5.0) × (0.00 + 1) / 2
base = 5.0 + (-7.0) × 0.5
base = 1.5°

# 4. Apply latitude adjustment
adjustment = (52.0 - 50.0) × 0.2 = 0.4°
final = 1.5 + 0.4 = 1.9°

# Result: Threshold = 1.9° (halfway between summer and winter)

Sine Function Properties

Value Range: -1 to +1

         1.0 ┤     ╭───╮
             │   ╱       ╲
         0.5 ┤ ╱           ╲
             │╱             ╲
         0.0 ┼               ╲     ╱
             │                ╲   ╱
        -0.5 ┤                 ╲ ╱
             │                  ╰
        -1.0 ┤
             └─┬───┬───┬───┬───┬─
              0   π/2  π  3π/2 2π
           (Day 80) (172) (266) (355)

Transformation to 0-1 range:

normalized = (sin_value + 1) / 2

This ensures smooth interpolation between winter (0) and summer (1) values.

🧪 Testing & Verification

Check Current Values

Developer Tools → Template → Test this:

{{ states('sensor.sun_elevation_up_dynamic') }}
{{ states('sensor.sun_elevation_down_dynamic') }}

Should return numbers like: 2.3 and 0.1

Verify Seasonal Changes

Check values at different dates:

{# Current date #}
{{ states('sensor.sun_elevation_up_dynamic') }}

{# Simulate summer (Day 172) #}
{% set day = 172 %}
{% set lat = state_attr('zone.home', 'latitude') | float(50.0) %}
{% set summer = -2.0 %}
{% set winter = 5.0 %}
{% set seasonal_factor = sin(2 * pi * (day - 80.75) / 365) %}
{% set base = winter + (summer - winter) * (seasonal_factor + 1) / 2 %}
{% set adjustment = (lat - 50) * 0.2 %}
{{ (base + adjustment) | round(1) }}
{# Should be close to -2.0° #}

{# Simulate winter (Day 355) #}
{% set day = 355 %}
{# ... same calculation ... #}
{# Should be close to 5.0° (or adjusted for your latitude) #}

Test with Automation

Enable Automation Traces to verify sensor usage:

  1. Developer Tools → States → Find your CCA automation
  2. Click ⋮ menu → Traces
  3. Look for trigger t_open_5 or t_close_5
  4. Check value_template shows sensor value

🐛 Troubleshooting

Sensor shows “unknown” or “unavailable”

Cause: Template syntax error or missing zone.home

Solution:

  1. Check Configuration → Logs for template errors
  2. Verify zone.home exists in Developer Tools → States
  3. Check latitude is valid: {{ state_attr('zone.home', 'latitude') }}

Values seem incorrect

Cause: Default values don’t match your preferences

Solution: Adjust summer/winter reference values (see Customization)

Covers open/close at wrong times

Diagnosis table:

Problem Current Threshold Action
Opens too early Too low (e.g., -3°) Increase summer/winter values
Opens too late Too high (e.g., +8°) Decrease summer/winter values
Closes too early Too high (e.g., +5°) Decrease summer/winter values
Closes too late Too low (e.g., -6°) Increase summer/winter values

Automation not using sensors

Check:

  1. ✅ Sensors exist and show numeric values
  2. ✅ CCA automation configured with sensor entities
  3. ✅ CCA version supports dynamic sensors (2025.XX.XX+)
  4. ✅ Fixed values in CCA are not set to same values as sensors

Sensors not updating

Normal behavior: Sensors update when:

Not needed: Sensors don’t need to update more than once per day - daily changes are gradual.

🌐 Regional Adaptations

Northern Europe (55-70°N)

Extreme seasonal variation requires wider range:

# Opening sensor
{% set summer = -5.0 %}  # Much lower minimum
{% set winter = 7.0 %}   # Much higher maximum

# Closing sensor
{% set summer = -4.0 %}
{% set winter = 3.0 %}

Mediterranean (35-45°N)

Less variation, higher year-round sun:

# Opening sensor
{% set summer = -4.0 %}  # Lower baseline
{% set winter = 8.0 %}   # Higher baseline

# Closing sensor
{% set summer = -2.0 %}
{% set winter = 4.0 %}

Southern Hemisphere

Invert the seasons by adding 182.5 days (6 months):

{% set seasonal_factor = sin(2 * pi * (day - 80.75 + 182.5) / 365) %}

This shifts the curve so:

📚 Advanced Topics

Non-Linear Latitude Adjustment

For extreme latitudes, use quadratic adjustment:

{% set lat_diff = lat - 50 %}
{% set adjustment = lat_diff * 0.2 + (lat_diff ** 2) * 0.01 %}

This increases sensitivity at higher/lower latitudes.

Monthly Lookup Tables

For maximum control, use discrete monthly values:

{% set month = now().month %}
{% set monthly_values = {
  1: -2.0, 2: -1.0, 3: 1.0, 4: 3.0,
  5: 4.5, 6: 5.0, 7: 4.5, 8: 3.0,
  9: 1.0, 10: -1.0, 11: -1.5, 12: -2.0
} %}
{{ monthly_values[month] }}

Hysteresis Integration

Add hysteresis to prevent rapid oscillation:

# In CCA configuration
Sun Elevation Up: 5.0°
Brightness Hysteresis: 1000 lx  # Add this for stability

Hysteresis is handled by CCA, not in the sensors.

💡 Pro Tips

1. Start Conservative

Use default values for 1-2 weeks before adjusting. This helps you understand baseline behavior.

2. Adjust in Small Steps

Change values by ±0.5° to ±1.0° at a time. Large changes can cause unexpected behavior.

3. Seasonal Tuning

Fine-tune in spring/autumn (equinoxes) when changes are fastest. This ensures good behavior year-round.

4. Consider Obstacles

Account for buildings, trees, hills:

# Blocked sunrise by building - delay opening
{% set summer = 1.0 %}  # Higher = later
{% set winter = 7.0 %}

5. Different Sensors Per Room

East-facing rooms might need different values than west-facing:

# East (morning sun) - open earlier
sensor.sun_elevation_up_dynamic_east:
  {% set summer = -4.0 %}
  {% set winter = 3.0 %}

# West (evening sun) - open later
sensor.sun_elevation_up_dynamic_west:
  {% set summer = 0.0 %}
  {% set winter = 7.0 %}

6. Combine with Time Constraints

Use CCA’s time windows to limit operation:

Time Up Early: 06:00
Time Up Late: 10:00
+ Dynamic Sensor
= Opens between 06:00-10:00 when sun reaches threshold

7. Monitor with Graphs

Add sensors to Lovelace dashboard to visualize annual cycle:

type: history-graph
entities:
  - sensor.sun_elevation_up_dynamic
  - sensor.sun_elevation_down_dynamic
  - sun.sun
hours_to_show: 168  # 1 week
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