There are several factors that determine how many solar panels you will need for your home.  In this post we will explain how your historic electricity consumption, available roof space, the azimuth of your home, shading, soiling, and equipment selection effect the number of panels you need.

How Many Solar Panels to Power a House?

Historic Electrical Consumption -  To determine how much electricity a home solar energy system will need to produce to meet your needs, we will need to calculate the average amount of electricity you use.  To do this, it is best to average out your last 2 years of consumption.

Available Roof Space for Solar Panel Placement - Ideally solar panels on Southern California homes should face South, East, or West to spend as much time as possible in direct sunlight.  The best azimuth for solar panels to face is 180º.  The tilt of a roof also effects how much electricity a solar panel will produce.  Too flat of a tilt will not perform well in the winter months when the sun is low on the horizon, and too steep of a pitch reduces production in the summer months when the sun is almost directly overhead.  The perfect roof for Solar in Southern California faces due south, has a 14º to 18º tilt and is large enough to place as many solar panels as you need on 1 roof section.  However there is no need to fret because panels facing east or west, or panels with a less than optimal tilt will only see a small decrease in production. Shading - Solar panels require light to create electricity.  Shade will reduce the amount of electricity your solar panels produce.  We use a tool that calculates how much shade nearby trees, chimneys, and other objects will produce and where the shadows from these objects will be cast year round to be sure we place your panels in the best location. Soiling - Living in a particularly dusty area can effect the amount of energy your system will produce.  It is important to keep solar panels clear of dirt, dust, and debris.  It is recommended to clean your panels at least quarterly if you live in a dusty region. Equipment Selection - Solar panels come in many sizes, and have different efficiency levels.  The more efficient a solar panel is, the more electricity it can produce.  You can have 2 solar panels that are the same size but if the efficiency is different the more efficient panel will produce more power.  This can be important if you have limited roof space.  High efficiency solar panels typically cost a little bit more, but can be worth it in certain applications.

The best way to get an accurate answer to "How Many Solar Panels Do I Need" is to have a Free Consultation with a SolarMax Renewable Energy Consultant.  We will take a look at your unique situation and offer you the best available options.

Below is a link to a tool that can calculate the estimated production of a solar energy system based on the information above: