import math import json from datetime import datetime, timedelta from astral import LocationInfo from astral.sun import sun, elevation, azimuth import pytz class BackSideOnlySimulation: def __init__(self): # Panel specifications (Hanersun N-TOPCon 700W) self.panel_power = 700 # watts self.panel_efficiency = 0.225 # 22.5% self.bifaciality_factor = 0.80 # Average of 75-85% self.panel_area = 2.384 * 1.303 # m² # Location: Lago Brown, Chile self.location = LocationInfo("Lago Brown", "Chile", "America/Santiago", -47.3919449, -72.3174973) self.timezone = pytz.timezone('America/Santiago') # Direct Normal Irradiance - constant when sun is shining (ideal conditions) self.dni_clear_sky = 900 # W/m² for clear sky conditions # Different albedo values for comparison self.albedo_types = { 'clay': 0.15, # jíl 'grass': 0.25, # tráva 'sand': 0.35, # písek 'concrete': 0.40, # beton 'snow_old': 0.65, # starý sníh 'snow_fresh': 0.85 # čerstvý sníh } def get_solar_position(self, date, hour, minute=0): """Get precise solar position using astronomical calculations""" dt = datetime(date.year, date.month, date.day, hour, minute, 0) dt = self.timezone.localize(dt) # Get solar elevation and azimuth solar_elevation = elevation(self.location.observer, dt) solar_azimuth = azimuth(self.location.observer, dt) return solar_elevation, solar_azimuth def calculate_panel_self_shading(self, panel_tilt, solar_elevation): """Calculate how much panel shades its own ground reflection area""" if panel_tilt >= 90: # Vertical panel - no self-shading return 1.0 if solar_elevation <= 0: return 0.0 # For tilted panels, calculate shadow effect # More tilted panel = more self-shading of ground shadow_angle = math.radians(panel_tilt) sun_angle = math.radians(solar_elevation) # Shadow length factor - how much ground is shaded if solar_elevation < panel_tilt: # Low sun - significant shading shadow_factor = 0.3 + 0.7 * (solar_elevation / panel_tilt) else: # High sun - less shading shadow_factor = 0.7 + 0.3 * math.cos(shadow_angle - sun_angle) return max(0.2, min(1.0, shadow_factor)) # Between 20-100% def calculate_diffuse_view_factor(self, panel_tilt): """Calculate view factor for diffuse sky radiation""" # View factor to sky for back side of tilted panel tilt_rad = math.radians(panel_tilt) if panel_tilt == 90: # Vertical sky_view_factor = 0.5 # Sees half the sky else: # Tilted panel back side - sees more sky as it tilts away from ground sky_view_factor = (1 - math.cos(tilt_rad)) / 2 return sky_view_factor def calculate_ground_view_factor(self, panel_tilt): """Calculate view factor for ground reflection""" tilt_rad = math.radians(panel_tilt) if panel_tilt == 90: # Vertical ground_view_factor = 0.5 # Sees half the ground else: # Tilted panel back side - sees more ground as it tilts toward ground ground_view_factor = (1 + math.cos(tilt_rad)) / 2 return ground_view_factor def calculate_back_side_irradiance(self, date, hour, minute, panel_tilt, ground_albedo): """Calculate irradiance on back side only - no direct light""" solar_elev, solar_az = self.get_solar_position(date, hour, minute) if solar_elev <= 0: return 0 # No sun # 1. DIFFUSE SKY RADIATION (isotropic sky model) diffuse_factor = 0.15 # 15% of total radiation is diffuse sky_diffuse = self.dni_clear_sky * diffuse_factor # View factor to sky for back side sky_view_factor = self.calculate_diffuse_view_factor(panel_tilt) back_diffuse = sky_diffuse * sky_view_factor # 2. GROUND REFLECTED RADIATION # Total ground irradiance (direct + diffuse) ground_irradiance = self.dni_clear_sky * math.sin(math.radians(solar_elev)) + sky_diffuse # Ground reflection ground_reflected = ground_irradiance * ground_albedo # View factor to ground for back side ground_view_factor = self.calculate_ground_view_factor(panel_tilt) # Self-shading effect - tilted panels shade their reflection area self_shading_factor = self.calculate_panel_self_shading(panel_tilt, solar_elev) back_ground = ground_reflected * ground_view_factor * self_shading_factor # Total back side irradiance total_back_irradiance = back_diffuse + back_ground # Apply bifacial efficiency back_irradiance_effective = total_back_irradiance * self.bifaciality_factor return back_irradiance_effective def calculate_monthly_production_back_only(self, panel_tilt, ground_albedo, albedo_name): """Calculate monthly energy production for back side only""" monthly_production = {} # Only winter months: May, June, July, August winter_months = [5, 6, 7, 8] for month in winter_months: # Representative date for month (15th day) date = datetime(2024, month, 15) daily_production = 0 half_hourly_data = [] # Calculate for each half hour of the day (48 intervals) for half_hour in range(48): hour = half_hour // 2 minute = 0 if half_hour % 2 == 0 else 30 back_irr = self.calculate_back_side_irradiance(date, hour, minute, panel_tilt, ground_albedo) if back_irr > 0: # Power calculation: only from back side power = (back_irr / 1000) * self.panel_power # Energy for 30 minutes (0.5 hour) daily_production += power * 0.5 time_str = f"{hour:02d}:{minute:02d}" half_hourly_data.append({ 'time': time_str, 'solar_elevation': round(self.get_solar_position(date, hour, minute)[0], 1), 'back_irradiance': round(back_irr, 2), 'power': round(power, 1) }) else: time_str = f"{hour:02d}:{minute:02d}" half_hourly_data.append({ 'time': time_str, 'solar_elevation': 0, 'back_irradiance': 0, 'power': 0 }) # Days in month days_in_month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31][month-1] monthly_energy = daily_production * days_in_month / 1000 # kWh monthly_production[month] = { 'energy_kwh': round(monthly_energy, 1), 'daily_production': round(daily_production, 1), 'half_hourly_data': half_hourly_data } return monthly_production def run_simulation(self): """Run back-side only simulation for all configurations and albedo types""" configurations = [ {'name': 'Vertical North-South', 'tilt': 90}, {'name': 'Tilt 20°', 'tilt': 20}, {'name': 'Tilt 30°', 'tilt': 30}, {'name': 'Tilt 45°', 'tilt': 45}, {'name': 'Tilt 60°', 'tilt': 60}, {'name': 'Tilt 70°', 'tilt': 70} ] results = {} for albedo_name, albedo_value in self.albedo_types.items(): print(f" Albedo {albedo_name} ({albedo_value}):") albedo_results = {} for config in configurations: print(f" - {config['name']}") production = self.calculate_monthly_production_back_only(config['tilt'], albedo_value, albedo_name) albedo_results[config['name']] = production results[albedo_name] = albedo_results return results def generate_html_report(self, results): """Generate HTML report for back side only simulation""" months_czech = ['Květen', 'Červen', 'Červenec', 'Srpen'] months_english = ['May', 'June', 'July', 'August'] winter_months = [5, 6, 7, 8] html_content = f""" Analýza POUZE zadní strany panelu - Zimní měsíce - Lago Brown, Chile

🌅 Analýza POUZE zadní strany bifaciálního panelu

Hanersun N-TOPCon 700W • Zimní měsíce • Různá albeda povrchů

🔬 Fyzikální model zadní strany panelu

🌍 Albedo různých povrchů

""" albedo_descriptions = { 'clay': 'Jíl (původní simulace)', 'grass': 'Tráva (střední odrazivost)', 'sand': 'Písek (vyšší odrazivost)', 'concrete': 'Beton (stavební povrch)', 'snow_old': 'Starý sníh (vysoká odrazivost)', 'snow_fresh': 'Čerstvý sníh (maximální odrazivost)' } for albedo_name, albedo_value in self.albedo_types.items(): desc = albedo_descriptions.get(albedo_name, albedo_name) html_content += f"""
{albedo_name.title()}: {albedo_value}
{desc}
""" html_content += """

📊 Měsíční výroba - POUZE zadní strana panelu

""" # Generate table for each month config_order = ['Vertical North-South', 'Tilt 20°', 'Tilt 30°', 'Tilt 45°', 'Tilt 60°', 'Tilt 70°'] for month_idx, month in enumerate(winter_months): month_name = months_english[month_idx] month_czech = months_czech[month_idx] html_content += f"""

{month_czech} ({month_name}) - Pouze zadní strana

""" for config in config_order: html_content += f"" html_content += """ """ # Add rows for each albedo type for albedo_name, albedo_value in self.albedo_types.items(): html_content += f""" """ # Find best value for highlighting month_values = [] for config in config_order: value = results[albedo_name][config][month]['energy_kwh'] month_values.append(value) best_value = max(month_values) for config in config_order: value = results[albedo_name][config][month]['energy_kwh'] cell_class = 'best-value' if value == best_value else '' html_content += f"" html_content += "" html_content += "
Albedo / Konfigurace{config}
{albedo_name.title()}
({albedo_value})		{value}
" html_content += """

📝 Pozorování z tabulky:

  • Vertikální panely mají nejlepší výkon při vysokém albedu (sníh)
  • Self-shading efekt - nakloněné panely ztrácí část ground reflection
  • Albedo má obrovský vliv - čerstvý sníh vs jíl = 5-6x rozdíl
  • Nejlepší konfigurace se mění podle albeda povrchu

🌅 Simulace pouze zadní strany panelu s různými albedy
Datum: 12.08.2025
Poznámka: Bez přímého slunce - pouze difúzní světlo a ground reflection

""" with open('/home/www/claudev.cz/orb3/solar_panel_report_back_side_only.html', 'w', encoding='utf-8') as f: f.write(html_content) def main(): simulation = BackSideOnlySimulation() print("🌅 Spouštím simulaci POUZE zadní strany panelu...") print(f"Panel: Hanersun N-TOPCon 700W Bifacial") print(f"Lokace: {simulation.location.latitude}°, {simulation.location.longitude}°") print("Zimní měsíce: Květen, Červen, Červenec, Srpen") print("Albeda: jíl, tráva, písek, beton, starý sníh, čerstvý sníh") print() # Run simulation print("Running back-side only simulation...") results = simulation.run_simulation() # Generate HTML report simulation.generate_html_report(results) print() print("✅ HTML report pouze zadní strany byl vytvořen: solar_panel_report_back_side_only.html") # Show comparison print() print("📊 Porovnání albeda pro červen, vertikální panel:") for albedo_name, albedo_value in simulation.albedo_types.items(): energy = results[albedo_name]['Vertical North-South'][6]['energy_kwh'] print(f" {albedo_name} ({albedo_value}): {energy} kWh") if __name__ == "__main__": results = main()