Van Conversion Solar Panel Calculator

Our Solar Calculator is designed to help you determine the ideal solar panel wattage for your van conversion. By inputting your daily energy consumption, average sun hours per day, and solar panel efficiency, the calculator will provide an accurate estimate of the required solar panel wattage. This calculation assumes you want to run only from solar without using other power sources like shore power or split charging.

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Formulas Used

The primary formulas used in this calculator are:

 

Required Solar Panel Wattage (W) = Daily Energy Consumption (Wh) / (Average Sun Hours per Day × Panel Efficiency)

 

Area Required (m²) = Required Solar Panel Wattage (W) / Solar Panel Wattage per m²

 

This formula ensures that the solar panel capacity accounts for your energy needs based on your location's average sun hours and the efficiency of the solar panels.

 

Solar Panel Efficiency

The typical efficiency of monocrystalline solar panels ranges from 18-20%. This means that 18-20% of the sunlight that hits the panel is converted into electrical energy. Several factors can affect the efficiency of solar panels, including:

• Temperature: High temperatures can reduce the efficiency of solar panels. Most panels are tested at 25°C (77°F), and efficiency decreases as the temperature rises.

• Shade: Even partial shading of a panel can significantly reduce its efficiency. It's important to install panels in locations that receive full sunlight.

• Angle and Orientation: The tilt angle and orientation of the solar panels can affect their performance. Panels should be angled to maximize exposure to the sun throughout the year. Optimal tilt means panels are directly facing the sun at the ideal angle for maximum efficiency, which can improve efficiency by 10-20% or more.

• Dirt and Debris: Accumulation of dirt, dust, and other debris on the surface of the panels can reduce their efficiency. Regular cleaning is necessary to maintain optimal performance.

• Age: Solar panels degrade over time, with a typical degradation rate of about 0.5-1% per year. This means that after 20 years, a panel might operate at around 80-90% of its original efficiency.

 

Effect of Solar Panel Tilt

The graphic below shows the effect of solar panel tilt on power output in summer versus winter. Optimal tilt significantly improves power output, especially during winter months. For an 800W solar array, in summer you might expect an increase from 5kWh to 6kWh when you tilt optimally. But the big difference comes in winter with a jump from 2kWh to 4kWh.