Are you thinking about going solar for your home? One of the first things you should consider is which direction your solar panels should face on the roof. You must determine the best direction for your brand-new solar panels in order for them to generate the most power.
In general, the professional who comes to install your solar panels will assist you in determining the best direction. If you live in the United States, however, you must follow the rule of thumb that your solar panels should face true south.
Why? It’s simple: the more sunlight that hits your panels, the more electricity you’ll generate. This translates to lower electricity bills.
True South vs Regular South
The compass indicates regular south, also known as “magnetic” south. True, a compass does not show the true south. A compass shows the earth’s geomagnetic field’s south pole. The general direction is correct, but it is not entirely precise. The iron and nickel in the earth’s outer core cause the compass needle to deviate slightly from “true” south.
To correct the compass reading, the solar installer will calculate the magnetic declination of your location. Another method for determining true south is to observe the shadows at noon, when shadows from vertical objects fall from north to south. You can also look at Google Earth’s view of your house; if you center the focus on your house and select “Grid” from the View menu, you can see Google’s north-south gridlines.
What should you do if the roof does not face south?
If your roof faces east-west, you can compensate by using larger collectors or more solar panels to increase the solar collector. You can also choose to mount the panels somewhere other than your roof, such as a south-facing wall or your yard. Remember to always mount the panels on the ground if you go with the yard. It is not only cost-effective, but it also provides easy access when cleaning the panels.
Select the Best Tilt for Your Solar Panels
Your solar installer will also assist you in determining the best tilt for your system by calculating the angle based on your latitude. In the United States, multiply your latitude by 0.76, then add 3.1 degrees. Consult with the installer for more specific information on the ideal tilt of panels.
Despite the fact that most people prefer a fixed position, you can adjust the panel angle depending on the season to ensure you get the most power. In general, as you get closer to the equator, your solar panels should start facing straight, and as you get closer to the poles, they should be aimed lower in the sky.
There is one exception to the rule
If you live in an area with high time-of-use electricity rates, you should probably disregard the “true south” rule. Many people use more electricity in the evening when they get home from school or work and turn on various appliances such as TVs, air conditioners, microwaves, and so on.
Some utility companies try their hardest to avoid the evening surge in electricity usage by raising the cost of electricity during these times. That is where you, as a solar owner, can save some money. Installing solar panels on your roof reduces your reliance on the grid, which means you use less power during peak hours. However, if your panels are facing south, they will not produce as many kilowatt-hours as they could if they were oriented to catch the afternoon sun.