Can I calculate my solar array needs for different seasons?

Understanding Seasonal Energy Demand

To calculate your solar array needs for different seasons, you need to know your energy usage patterns. Start by analyzing your past energy bills or create a detailed energy usage schedule. For example, let’s say you consume 3,000 kWh of electricity per month during the summer, but only 2,500 kWh during the winter. You’ll want to use the higher summer usage number to determine your solar array size, as it will be the most demanding time of year.

Calculating Peak Sun Hours (PSH)

To accurately size your solar array, you need to know the number of peak sun hours (PSH) your location receives per year. PSH is a measure of the amount of sunlight your solar panels receive during the peak sun hour, typically between 9am and 3pm. In the United States, PSH varies depending on your latitude and time of year. For example, a location at 35°N latitude receives about 5.5 hours of PSH in the summer, but only 4.5 hours in the winter. You can use online tools or consult with a solar professional to determine your specific PSH numbers.

Sizing Your Solar Array

Once you have your energy usage patterns and PSH numbers, you can calculate your solar array size. A general rule of thumb is to oversize your solar array by 20-30% to account for system losses and ensure you meet your energy demands. For our example, let’s say you need a 10 kW solar array to meet your summer energy demands, and your location receives 5.5 hours of PSH in the summer. Using a solar array sizing tool or consulting with a solar professional, you can determine that a 12 kW solar array would be a suitable size for your needs, taking into account system losses and PSH variations throughout the year.