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Solar Planner

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Solar Planner

Comprehensive solar planning: weather analysis, peak sun hours, tilt optimization, and power generation estimates

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Location Specifications

Historical Weather Averages

Temperature & Humidity

Historical weather averages inform HVAC load planning. Hot months (above 25°C) also cause solar panel efficiency losses—panels lose ~0.4% output per degree above 25°C. Use humidity data to estimate dehumidifier loads in humid climates (35-50W per 10% above 50% RH in poorly insulated spaces).

Month High (°F) Low (°F) Mean (°F) Humidity (%) Wind Gusts (mph) Wind Speed (mph) Max Wind Gust (mph)

Wind Speed

Wind data helps you plan for structural loads and cooling effects. Maximum monthly wind gusts inform mounting hardware requirements (most panels are rated for 50-60 mph sustained winds). Higher sustained winds can actually improve panel efficiency by cooling them, reducing temperature derating losses by 1-2%. Use this data when selecting mounting systems and evaluating site exposure.

Peak Sun Hours (PSH) & Panel Tilt Angle

kWh/m²/day on panel surface at different tilt angles

Peak Sun Hours (PSH) represents the average daily solar energy received per square meter of panel surface. Higher PSH means your system can be smaller and cheaper while producing the same energy. For example, a location with 6 PSH needs only half the panels of a location with 3 PSH to generate the same power. Monthly Optimal Tilt adjusts the panel angle each month for maximum energy capture (+10-20% annually), while Yearly Fixed Tilt uses a constant angle set to the location's latitude (simpler installation, slightly lower output).

Tilt angles show optimal panel orientation. Monthly Optimal Tilt tracks the sun's seasonal path (e.g., 60° in winter, 20° in summer at 40° latitude) for maximum output. Yearly Fixed Tilt uses your latitude angle (simplest—panels never move). At 40° latitude, winter production is ~30% lower than summer regardless of tilt method due to shorter days and sun angle.

Month Monthly Optimal Yearly Fixed Flat (0°)
Tilt (°) PSH Tilt (°) PSH PSH

System Specifications

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Solar Power Generation

Estimate your solar panel output based on PSH data

Power generation estimates for each month, comparing three tilt methods. Monthly Optimal Tilt maximizes output (+10-20% annually) but requires adjustable mounts ($200-500 extra). Yearly Fixed Tilt is the most common (simplest installation, latitude angle). Flat (0°) loses 10-30% efficiency but is necessary for flat roofs or RV installations. Compare annual totals to your electrical loads to size your system.

Month Monthly Optimal Yearly Fixed Flat (0°)
Daily (kWh) Monthly (kWh) Daily (kWh) Monthly (kWh) Daily (kWh) Monthly (kWh)
Annual Total - - -

Enter your panel wattage above to see estimated power generation

Hourly Power Generation

Generation vs. Consumption Comparison

Compare your solar generation against total electrical loads

Solar generation compared to electrical load consumption for each month. Positive values (green) mean excess solar that can charge batteries or feed the grid. Negative values (red) mean you'll need battery reserves, grid power, or generator backup. Aim for 100%+ annual coverage to account for weather variability and system degradation over time.

Month Solar Generation Consumption Surplus
(kWh/month) (kWh/day) (kWh/month) (kWh/day) (kWh/month) (kWh/day)
Annual Total - - -

Enter panel wattage and add loads to see comparison

% Loads Covered by Solar

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Battery Capacity Needed

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This is the minimum usable battery bank size to power your loads for the configured days without solar input.

Generator Size Recommended

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This accounts for your peak load plus 20% safety margin for motor startup surges. Actual runtime during deficit periods depends on battery capacity. Diesel generators typically cost $0.30-0.50 per kWh in fuel alone.

Generator Annual Runtime

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Generator Annual Fuel

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Total Annual Solar Generation

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Average Daily Solar Generation

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Total Annual Consumption

0.00 kWh/year

Average Daily Consumption

0.00 kWh/day

Raw weather data from Visual Crossing Weather API.

Calculations and Analysis performed by Copper Tech.

© 2026 Copper Tech LLC. All rights reserved.

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Saved System Configurations

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Solar Panel Configuration

W

The total rated power output of all solar panels in watts under standard test conditions (STC).

%

System efficiency accounting for inverter losses (~3-4%), wiring losses (~1-2%), and mismatch losses (~1-2%).

Accounts for power loss from dust, dirt, pollen, and bird droppings on panels. 0.95 = 5% loss (occasional cleaning), 0.90 = 10% loss (infrequent cleaning).

Battery & Generator Configuration

Battery Settings

%

Usable battery capacity. 80% is recommended for lithium batteries.

days

Consecutive days of backup power without solar input. Off-grid systems: 3-5 days (account for extended cloudy periods), Grid-tied with backup: 1-2 days (short outages only). More days = larger, more expensive battery bank. For reference, a 7-day autonomy doubles your battery investment compared to 3 days.

%

Round-trip efficiency (charge + discharge losses combined). Lithium batteries: 90-95% (recommended default: 92%), Lead-acid batteries: 70-85%. Higher efficiency means less solar oversizing needed. For example, with 90% efficiency, you need 10% more solar panels to account for charging losses.

Generator Settings

L/kWh

Diesel: 0.25-0.30 L/kWh, Gas: 0.30-0.40 L/kWh (at 75% load).

hrs/day

Estimated hours the generator runs on days when solar generation falls short of loads. Conservative estimate: 6-8 hours (covers evening peak and morning loads). Actual runtime depends on battery capacity—larger batteries reduce generator cycles. For example, with 10 kWh of batteries, you might only need 4-6 hours of generator runtime.

%

Oversizing for startup surges. 20% recommended.

Electrical Loads

Understanding System Losses

System Efficiency accounts for electrical conversion losses:

  • Inverter efficiency (~96-98%): Converting DC to AC power
  • Wiring losses (~1-2%): Resistance in cables
  • Mismatch losses (~1-2%): Panels don't all perform identically

Default 82% efficiency = 96% inverter × 98% wiring × 98% mismatch × 98% other.

Temperature Derating (automatic): Panels lose ~0.4% per °C above 25°C. On hot days (60°C cell temp), expect ~14% power reduction.

Soiling Factor accounts for dirt accumulation:

  • 0.98-1.00 (2% loss): Weekly cleaning, rainy climate
  • 0.95 (5% loss): Monthly cleaning, typical (default)
  • 0.90-0.92 (8-10% loss): Infrequent cleaning, dusty/arid climate

Common Household Loads

  • Refrigerator: 150-800W, 24 hrs/day
  • Air Conditioner: 1000-3500W, 4-12 hrs/day
  • Water Heater: 3000-4500W, 2-4 hrs/day
  • LED Lighting: 10-20W per bulb, 4-8 hrs/day
  • TV: 50-200W, 4-8 hrs/day
  • Computer: 100-400W, 4-12 hrs/day
  • Washer/Dryer: 1500-5000W, 1-2 hrs/day
  • Dishwasher: 1200-1500W, 1-2 hrs/day

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